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RE: [hreg] Green Homes 101 - Wall Systems

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  • Gary Beck
    Thanks, I had a long flight so I’m reply with more detail. What is the best a generic name to best describe the system in this photo? Several manufacturers
    Message 1 of 10 , Nov 17, 2004
    • 0 Attachment

      Thanks, I had a long flight so I’m reply with more detail.

       

      What is the best a generic name to best describe the system in this photo?  Several manufacturers have supplied this type of panel system. They all have 2 to 4 inch foam cores (1), factory sandwiched between 2" x 2" heavy steel grids (2) which connected by steel truss wires (3), completed with each side getting field applied about 1 ¼ to 1 ½ inches* of shotcrete or gunite (4)  (*minimum of ¾ inches of concrete covering the steel).  

       

      The more recognized “ICF” system (Insulated Concrete Form) describes a ‘concrete-and-rebar-on-the-inside’ system available from many manufacturers. ICF companies are also more prevalent. But for this type of manufacturer panel system, what generic name best describes it?  Maybe use ‘grid wall’, without any caps and without hyphens, or “ICW” for Insulated Concrete Wall (probably also trademarked). 

       

      Trademarks** aside, I agree ‘ICW’ style systems have been around for a while, but unfortunately were skipped in latest IRC-2003 which has added and recognized ICF probably due to prevalence.   This prevalence is probably also since it is basically easier to find companies to pump concrete inside an ICF wall, than it is to find a company to apply concrete or shotcrete to the outside of ‘ICW’ walls.  For ‘ICW’ systems (I like that) I believe the “3D” brand was developed in Austria, but apparently this was after several small US companies made different styles panels and panel manufacturing machines. Besides Mexico (where ICW is also used for roof and deck flooring) and the pockets of projects in the Western US, ICW systems are used more in Austria and Germany where masonry homes are more the norm.  

       

      For a coastal installation, I don’t see how there would be a significant salt air corrosion issue for this type of reinforced concrete system, any more than a wood frame house would have with steel nails.  Nails are about 10 gauge, and while the grid wire in these ‘ICW’ panels is smaller at 12 to 14 gauge, connected by 11 gauge, all steel is fully encapsulated in concrete. All these grid wall systems require a minimum of ¾ inch of concrete OVER the steel grid. The ¾” inside and outside comes from accepted concrete practices, and is probably listed somewhere in ACI or IBC specifications.  After the ¾ inches of concrete, typically masonry paint or similar colored coating system is applied on top of the concrete exterior to provide further water protection. You could probably get a similar added protection by adding polymer plus pigment to the concrete.  

       

      To my thinking the real safety design advantage comes from repetitive application of the steel inside the wall, somewhat similar to a nailed diaphragm wall in wood frame. Having 14 to 12 gauge steel every 2 inches horizontally and vertically on both inside and outside is very repetitive. And for coastal construction, my primary concern is for wind storm resistance for which both ICF and ICW systems outperform everything.

       

      Regarding past projects, I am not familiar with ‘SolarWall’ - is a thermal mass system? The La Porte house I supported used ICW type panels supplied from Ft Worth that were made by original ‘Archer’ machines.  A few years ago I saw a project which used 3D manufactured panels go up on Bissonette near Rice University. I have been told that several area churches have been built from Archer or other ICW panels, one somewhere the west side of town near Alief. I’m sure there are probably 30 to 50 structures in the Houston area which used this type system.  

       

      I like the ICW (or grid wall) type systems for their strength and apparent low installed cost. Cost is always a strong driving force behind any new home building system adoption, and time will tell if ICF and ICW become more broadly adapted. As an engineer, I also support the American Wood Council’s design approaches to High Wind Resistant Wood Frame Construction for anything near the coast. In the low income home in La Porte we applied a high wind wood frame roof system to ICW walls for lowest cost, but the optimal design would use a SIP roof system on ICW or ICF walls. But what can I say? I’m a civil engineer and like the ‘magic mud’ of concrete in all its forms. So I like these quiet, strong, pest resistant and energy efficient ICF/IWC homes, especially in a hurricane.

       

      Gary Beck, P.E.  Tel: 713-530-1950

      Eco-Holdings LLC

      Low Energy and Wind Storm Design

       

      ** PS: I wonder if 2x4™ or Stud™ is owned by Kirby or Weyerhauser?…hmmm

       

      -----Original Message-----
      From: Environment Associates Architects [mailto:laverne@...]
      Sent: Monday, November 15, 2004 11:15 PM
      To:
      hreg@yahoogroups.com
      Subject: Re: [hreg] Green Homes 101 - Wall Systems

       

      Gary:

       

      FYI, there is a trade marked product called GridWall that is similar to Rastra and PerformWall that is manufactured in San Antonio.  So I guess you will have to come up with another name since Amazon Forms One, Inc., probably won't be very enthusiastic about using their Grid-Wall (TM) name for the system you described.  Go to www.AmazonGridwall.com

       

      I'm curious.  What you described sounds very similar to a product called "SolarWall" that I used to build a home I designed in the late 70's.  Nearer the coast, where corrosion from salty air is a real problem, how corrosion resistant is the reinforcing in the system you described? I have to assume that it should be as it is probably galvanized after being welded together.  Is this assumption correct?  Whose system are you actually using for the projects you describe?  Are you familiar with a home built with this "SolarWall" system in the late 70's west of Houston off SH359 between Alt US 90 & Katy?

       

      It is good to know you provide engineering support services.

       

      LaVerne A. Williams, AIA, LEED AP
      architect & building ecologist
      laverne@...
      ENVIRONMENT ASSOCIATES, Architects & Consultants
      5828 Langfield Road
      Houston, TX 77092-1429
      713.528.0000
      866.815.2527 toll free
      www.environmentassoc.com
      30 Years of Leadership in Healthy, High Performance Homes / Green Architecture

      Consulting / Design Counseling / Design / Construction Documents / Construction Administration Services

       

       

      ----- Original Message -----

      From: Gary Beck

      Sent: Monday, November 15, 2004 7:41 PM

      Subject: RE: [hreg] Green Homes 101 - Wall Systems

       

      Finding all these new green and energy efficient sources is more than half the battle!  I can not help with the recessed lighting, but I can help with wall and roof systems and would like to add comments on to the listed wall systems under paragraph 5:

       

      5.      Materials:

      a.       Rastra/Cempo/Perform Wall – blocks made from recycled polystyrene

      b.      Insulated Concrete Form (ICF) and Grid-Wall systems construction

      c.       Compressed Straw Walls – for interior

      d.      Hebel Block – aerated cement

      e.       Galvalume Roofing – 30 year roof product

      f.        Sarnafil Membrane roof

       

      In the listing of green or energy efficient wall building systems, between “a” and “b”, I suggest we should add the term ‘Grid-Wall’. This is my generic name for panels mfrd using steel grids over EPS core.  I became familiar with it last year when I engineered a low income ‘grid-wall’ pilot home in La Porte* (not very pretty but strong and inexpensive).  Now we are finishing a 2nd much nicer contemporary ranch grid-wall design that will soon go up soon nearer to Galveston Bay.

       

      I found that ‘grid-wall’ systems are very common in Mexico and somewhat common in the western US states, probably due with seismic issues. But this high strength also is perfect for Hurricane resistant homes and structures.    Grid-Wall type system has been provided under various names from various manufacturers under names like “3D-Panel”, “Archer-Panel”, “Z-Panel”, “W-Panel”.  I’m sure each mfr will say theirs is different and better, but regardless, all are much stronger than wood frame (3D did a 60,000 lb test load held by one 4’x8’ panel). All 4 systems I have researched appear fairly similar with a basic 2”x2” grid formed from 11 to 14 gauge galvanized steel welded wire rigidly held ¾” off each side of a 2 to 4 inch thick EPS panel core.  4’x8’ panels are field joined and then have 1.5 inches of shotcrete field added and finished to complete the system that is very very strong, termite proof, and very energy efficient.  

       

      Although these grid-walls are not yet common enough to be added into the new IRC 2003 (like the ICF systems), they still may be worth considering since a structural steel material comparison between most of the mfrs panels shows equal or greater steel area per linear foot than what the IRC 2003 requires for ICF construction.  I don’t know what a finished ICF system wall costs per sf of wall surface area, but I was able to help a recent project price the grid-wall at $4/wall-surface-sf installed on a 2500 sf home.  I have to assume that grid-wall costs can become very competitive since the 1.5 inch interior and exterior shotcrete sections is also the reinforced steel structure, so no added cost from covering with hardi-plank, brick, stucco, sheetrock etc. is required.

       

      For those interested in alternate systems like Grid-Wall, ICF, or Wood Frame High Wind Resistant design, ECO can provide engineering and design support.

       

      Gary Beck, P.E.

      Eco-Holdings LLC

      www.eco-holdings.com

      * We put up an info website based around this original LaPorte project called www.stormhaus.com

       

       

      -----Original Message-----
      From: Tom Ritter [mailto:tom@...]
      Sent: Monday, November 15, 2004 11:57 AM
      To:
      hreg@yahoogroups.com
      Subject: RE: [hreg] Green Homes 101 - Native and Water-wise Plants

       

      In the section 2 of the outline below, it mentions not using any recessed lights between conditioned space and the unconditioned attic and says there is a new product of an “air-tight recessed light”.  Does anyone know where I could find this light.  If they are not readily available, does anyone know where I can find insulation “caps” or something similar for my existing recessed lights in the above-mentioned location?

       

      Thanks for any input,


      Tom

       

      2.      Lighting:

      a.       Compact fluorescent rather than incandescent

                                                         i.      Larger first cost, but money saved in energy

                                                       ii.      Less heat produced (incandescent: 80% heat, 20% light)

                                                      iii.      Fewer watts required to light the same space

      b.      No recessed lights between conditioned space and unconditioned attic

                                                         i.      Insulation leak

                                                       ii.      New product: air-tight recessed lights, should reduce this problem

       

       


      From: Anica Landreneau [mailto:alandreneau@...]
      Sent: Monday, November 15, 2004 10:44 AM
      To: sustainable-houston@...; 'HREG'
      Subject: [hreg] Green Homes 101 - Native and Water-wise Plants

       

      RE: Residential Green Building education and training

       

      Dear Concerned Residents

       

      Green Homes 101 sponsored by Cultivate Green and Houston Advanced Research Center (HARC) was a great success.  We hope you will share what you learned and encourage others to participate in future seminars.  We the volunteers of the Cultivate Green program want to thank you for your participation in the Green Homes 101.  Remember that a green home can also be a remodeled dwelling so the possibilities for change are endless.

       

      Due to your interest and feedback from Green Homes 101, our next event will be 12/15/04 from 6:00-9:00pm and will address the use of native and water wise plants as a vital element of green residential development.  Mark Bowen and Charles Tapley will cover theses topics and share their wealth of knowledge concerning regional native plants and how and where to use them. This seminar will also be held at the U of H College of Architecture.

       

      The following is a recap the Green Homes 101 that you attended.

       

      Mike Myers of Aspen Building Systems led a wide ranging discussion of all aspects of what makes a home green as well as what products, materials, design practices, and site considerations do (or do not) go into green home.  Mike opened his conversation by stating a central theme of the evening: all components and systems in a building, and on the site, are (and should be) interconnected; it is a fallacy to consider any single aspect of the building in isolation from all the others.  For this reason, it is best to have as many points of view represented as possible when designing the home.  To demonstrate the problems created by the “design by components” paradigm, Mike brought up the example of ductwork; in most houses, the ducts are added as an unplanned afterthought, and follow contorted paths through the unconditioned attic.  In this paradigm, there are two major, unnecessary inefficiencies in the system: a larger pump is required to force air around all the curves, and energy is lost due to the large temperature difference between the (frequently leaky) ducts and the unconditioned attic.  Another important theme: just because it is the status quo does not mean that it makes any sense! 

       

      Products and specifics:

      1.      General:

      a.       Look for Energy Star label

      b.      Look for low or zero VOC products

      2.      Lighting:

      a.       Compact fluorescent rather than incandescent

                                                         i.      Larger first cost, but money saved in energy

                                                       ii.      Less heat produced (incandescent: 80% heat, 20% light)

                                                      iii.      Fewer watts required to light the same space

      b.      No recessed lights between conditioned space and unconditioned attic

                                                         i.      Insulation leak

                                                       ii.      New product: air-tight recessed lights, should reduce this problem

      3.      Insulation/sealing/climate control:

      a.       Important to ‘sandwich’ vertical insulation for efficiency

      b.      Seal home as completely as possible

                                                         i.      Dupont House Wrap

                                                       ii.      Requires mechanical ventilation system

      1.      Allows control of intake (location, filter, dehumidify)

      c.       Efficient use of air ducts

                                                         i.      Mastic, not duct tape for sealing

                                                       ii.      Ducts in conditioned space (or condition attic)

                                                      iii.      Minimize turns in ducts

      d.      Don’t forget to insulate behind the bathtub!

      4.      Water:

      a.       Rain water, capture in barrels

                                                         i.      Use for irrigation, commodes

      b.      Point of use/on demand water heating

                                                         i.      Save space (no storage tank)

                                                       ii.      Less piping required

                                                      iii.      Hot water immediately

                                                     iv.      Energy saved (do not heat pipes, or run water while waiting)

      5.      Materials:

      a.       Rastra/Cempo/Perform Wall – blocks made from recycled polystyrene

      b.      Insulated Concrete Form (ICF) construction

      c.       Compressed Straw Walls – for interior

      d.      Hebel Block – aerated cement

      e.       Galvalume Roofing – 30 year roof product

      f.        Sarnafil Membrane roof

       

      We look forward to seeing you at the next Cultivate Green Seminar.

       

      Thanks again,

      Brian Yeoman

       

       

      Anica Landreneau, LEED-AP

      Marketing Coordinator

      Browne Penland McGregor Stephens Architects, Inc.

      520 Post Oak Blvd. Suite 880

      Houston, TX 77027

      713.850.1733 x10

      alandreneau@...

      www.bpmsa.com

       

       

       

       

       




    • Gary Beck
      Thanks, I had a long flight so I’m replying with more detail (maybe too long - now in better English!). What is the best generic name to describe the system
      Message 2 of 10 , Nov 17, 2004
      • 0 Attachment

        Thanks, I had a long flight so I’m replying with more detail (maybe too long - now in better English!).

         

        What is the best generic name to describe the system in this photo?  Several manufacturers have supplied this type of panel system. They all have 2 to 4 inch foam cores (1), factory sandwiched between 2" x 2" heavy steel grids (2) which connected by steel truss wires (3), completed with each side getting field applied about 1 ¼ to 1 ½ inches* of shotcrete or gunite (4)  (*minimum of ¾ inches of concrete covering the steel).  

         

        The more recognized “ICF” system (Insulated Concrete Form) describes a ‘concrete-and-rebar-on-the-inside’ system available from many manufacturers. ICF companies are also more prevalent. But for this type of manufacturer panel system, what generic name best describes it?  Maybe use ‘grid wall’, without any caps and without hyphens, or “ICW” for Insulated Concrete Wall (probably also trademarked). 

         

        Trademarks** aside, I agree ‘ICW’ style systems have been around for a while, but unfortunately were skipped in latest IRC-2003 which has added and recognized ICF probably due to prevalence.   This prevalence is probably also since it is basically easier to find a company to pump concrete inside an ICF wall, than it is to find a company to apply concrete or shotcrete to the outside of ‘ICW’ walls.  For ‘ICW’ systems (I like that) I believe the “3D” brand was developed in Austria, but apparently this was after several small US companies made different styles panels and panel manufacturing machines. Besides Mexico (where ICW is also used for roof and deck flooring) and the pockets of projects in the Western US, ICW systems are used more in Austria and Germany where masonry homes are more the norm.  

         

        For a coastal installation, I don’t see how there would be a significant salt air corrosion issue for this type of reinforced concrete system, any more than a wood frame house would have with steel nails.  Nails are about 10 gauge, and while the grid wire in these ‘ICW’ panels is smaller at 12 to 14 gauge, connected by 11 gauge, all steel is fully encapsulated in concrete. All these grid wall systems require a minimum of ¾ inch of concrete OVER the steel grid. The ¾” inside and outside comes from accepted concrete practices, and is probably listed somewhere in ACI or IBC specifications.  After the ¾ inches of concrete, typically masonry paint or similar colored coating system is applied on top of the concrete exterior to provide further water protection. You could probably get a similar added protection by adding polymer plus pigment to the concrete.  

         

        To my thinking the real safety design advantage comes from repetitive application of the steel inside the wall, somewhat similar to a nailed diaphragm wall in wood frame. Having 14 to 12 gauge steel every 2 inches horizontally and vertically on both inside and outside is very repetitive. And for coastal construction, my primary concern is for wind storm resistance for which both ICF and ICW systems outperform everything.

         

        Regarding past projects, I am not familiar with ‘SolarWall’ - is a thermal mass system? The La Porte house I supported used ICW type panels supplied from Ft Worth that were made by original ‘Archer’ machines.  A few years ago I saw a project which used 3D manufactured panels go up on Bissonette near Rice University. I have been told that several area churches have been built from Archer or other ICW panels, one somewhere the west side of town near Alief. I’m sure there are probably 30 to 50 structures in the Houston area which used this type system.  

         

        I like the ICW (or grid wall) type systems for their strength and apparent low installed cost. Cost is always a strong driving force behind any new home building system adoption, and time will tell if ICF and ICW become more broadly adapted. As an engineer, I also support the American Wood Council’s design approaches to High Wind Resistant Wood Frame Construction for anything near the coast. In the low income home in La Porte we applied a high wind wood frame roof system to ICW walls for lowest cost, but the optimal design would use a SIP roof system on ICW or ICF walls. But what can I say? I’m a civil engineer and like the ‘magic mud’ of concrete in all its forms. So I like these quiet, strong, pest resistant and energy efficient ICF/IWC homes, especially in a hurricane.

         

        Gary Beck, P.E.  Tel: 713-530-1950

        Eco-Holdings LLC

        Low Energy and Wind Storm Design

         

        ** PS: I wonder if 2x4™ or Stud™ is owned by Kirby or Weyerhaeuser?…hmmm

         

        5.      Materials:

        a.       Rastra/Cempo/Perform Wall – blocks made from recycled polystyrene

        b.      Insulated Concrete Form (ICF) and Insulated Concrete Wall (ICW) systems construction

        c.       Compressed Straw Walls – for interior

        d.      Hebel Block – aerated cement

        e.       Galvalume Roofing – 30 year roof product

        f.        Sarnafil Membrane roof

         

        -----Original Message-----
        From: Environment Associates Architects [mailto:laverne@...]
        Sent:
        Monday, November 15, 2004 11:15 PM
        To:
        hreg@yahoogroups.com
        Subject: Re: [hreg] Green Homes 101 - Wall Systems

         

        Gary:

         

        FYI, there is a trade marked product called GridWall that is similar to Rastra and PerformWall that is manufactured in San Antonio.  So I guess you will have to come up with another name since Amazon Forms One, Inc., probably won't be very enthusiastic about using their Grid-Wall (TM) name for the system you described.  Go to www.AmazonGridwall.com

         

        I'm curious.  What you described sounds very similar to a product called "SolarWall" that I used to build a home I designed in the late 70's.  Nearer the coast, where corrosion from salty air is a real problem, how corrosion resistant is the reinforcing in the system you described? I have to assume that it should be as it is probably galvanized after being welded together.  Is this assumption correct?  Whose system are you actually using for the projects you describe?  Are you familiar with a home built with this "SolarWall" system in the late 70's west of Houston off SH359 between Alt US 90 & Katy?

         

        It is good to know you provide engineering support services.

         

        LaVerne A. Williams, AIA, LEED AP
        architect & building ecologist
        laverne@...
        ENVIRONMENT ASSOCIATES, Architects & Consultants
        5828 Langfield Road
        Houston, TX 77092-1429
        713.528.0000
        866.815.2527 toll free
        www.environmentassoc.com
        30 Years of Leadership in Healthy, High Performance Homes / Green Architecture

        Consulting / Design Counseling / Design / Construction Documents / Construction Administration Services

         

         

        ----- Original Message -----

        From: Gary Beck

        To: hreg@yahoogroups.com

        Sent: Monday, November 15, 2004 7:41 PM

        Subject: RE: [hreg] Green Homes 101 - Wall Systems

         

        Finding all these new green and energy efficient sources is more than half the battle!  I can not help with the recessed lighting, but I can help with wall and roof systems and would like to add comments on to the listed wall systems under paragraph 5:

         

        5.      Materials:

        a.       Rastra/Cempo/Perform Wall – blocks made from recycled polystyrene

        b.      Insulated Concrete Form (ICF) and Insulated Concrete Wall (ICW) systems construction

        c.       Compressed Straw Walls – for interior

        d.      Hebel Block – aerated cement

        e.       Galvalume Roofing – 30 year roof product

        f.        Sarnafil Membrane roof

         

        In the listing of green or energy efficient wall building systems, between “a” and “b”, I suggest we should add the term ‘Grid-Wall’. This is my generic name for panels mfrd using steel grids over EPS core.  I became familiar with it last year when I engineered a low income ‘grid-wall’ pilot home in La Porte* (not very pretty but strong and inexpensive).  Now we are finishing a 2nd much nicer contemporary ranch grid-wall design that will soon go up soon nearer to Galveston Bay.

         

        I found that ‘grid-wall’ systems are very common in Mexico and somewhat common in the western US states, probably due with seismic issues. But this high strength also is perfect for Hurricane resistant homes and structures.    Grid-Wall type system has been provided under various names from various manufacturers under names like “3D-Panel”, “Archer-Panel”, “Z-Panel”, “W-Panel”.  I’m sure each mfr will say theirs is different and better, but regardless, all are much stronger than wood frame (3D did a 60,000 lb test load held by one 4’x8’ panel). All 4 systems I have researched appear fairly similar with a basic 2”x2” grid formed from 11 to 14 gauge galvanized steel welded wire rigidly held ¾” off each side of a 2 to 4 inch thick EPS panel core.  4’x8’ panels are field joined and then have 1.5 inches of shotcrete field added and finished to complete the system that is very very strong, termite proof, and very energy efficient.  

         

        Although these grid-walls are not yet common enough to be added into the new IRC 2003 (like the ICF systems), they still may be worth considering since a structural steel material comparison between most of the mfrs panels shows equal or greater steel area per linear foot than what the IRC 2003 requires for ICF construction.  I don’t know what a finished ICF system wall costs per sf of wall surface area, but I was able to help a recent project price the grid-wall at $4/wall-surface-sf installed on a 2500 sf home.  I have to assume that grid-wall costs can become very competitive since the 1.5 inch interior and exterior shotcrete sections is also the reinforced steel structure, so no added cost from covering with hardi-plank, brick, stucco, sheetrock etc. is required.

         

        For those interested in alternate systems like Grid-Wall, ICF, or Wood Frame High Wind Resistant design, ECO can provide engineering and design support.

         

        Gary Beck, P.E.

        Eco-Holdings LLC

        www.eco-holdings.com

        * We put up an info website based around this original LaPorte project called www.stormhaus.com

         

         

        -----Original Message-----
        From: Tom Ritter [mailto:tom@...]
        Sent:
        Monday, November 15, 2004 11:57 AM
        To:
        hreg@yahoogroups.com
        Subject: RE: [hreg] Green Homes 101 - Native and Water-wise Plants

         

        In the section 2 of the outline below, it mentions not using any recessed lights between conditioned space and the unconditioned attic and says there is a new product of an “air-tight recessed light”.  Does anyone know where I could find this light.  If they are not readily available, does anyone know where I can find insulation “caps” or something similar for my existing recessed lights in the above-mentioned location?

         

        Thanks for any input,


        Tom

         

        2.      Lighting:

        a.       Compact fluorescent rather than incandescent

                                                           i.      Larger first cost, but money saved in energy

                                                         ii.      Less heat produced (incandescent: 80% heat, 20% light)

                                                        iii.      Fewer watts required to light the same space

        b.      No recessed lights between conditioned space and unconditioned attic

                                                           i.      Insulation leak

                                                         ii.      New product: air-tight recessed lights, should reduce this problem

         

         


        From: Anica Landreneau [mailto:alandreneau@...]
        Sent: Monday, November 15, 2004 10:44 AM
        To: sustainable-houston@...; 'HREG'
        Subject: [hreg] Green Homes 101 - Native and Water-wise Plants

         

        RE: Residential Green Building education and training

         

        Dear Concerned Residents

         

        Green Homes 101 sponsored by Cultivate Green and Houston Advanced Research Center (HARC) was a great success.  We hope you will share what you learned and encourage others to participate in future seminars.  We the volunteers of the Cultivate Green program want to thank you for your participation in the Green Homes 101.  Remember that a green home can also be a remodeled dwelling so the possibilities for change are endless.

         

        Due to your interest and feedback from Green Homes 101, our next event will be 12/15/04 from 6:00-9:00pm and will address the use of native and water wise plants as a vital element of green residential development.  Mark Bowen and Charles Tapley will cover theses topics and share their wealth of knowledge concerning regional native plants and how and where to use them. This seminar will also be held at the U of H College of Architecture.

         

        The following is a recap the Green Homes 101 that you attended.

         

        Mike Myers of Aspen Building Systems led a wide ranging discussion of all aspects of what makes a home green as well as what products, materials, design practices, and site considerations do (or do not) go into green home.  Mike opened his conversation by stating a central theme of the evening: all components and systems in a building, and on the site, are (and should be) interconnected; it is a fallacy to consider any single aspect of the building in isolation from all the others.  For this reason, it is best to have as many points of view represented as possible when designing the home.  To demonstrate the problems created by the “design by components” paradigm, Mike brought up the example of ductwork; in most houses, the ducts are added as an unplanned afterthought, and follow contorted paths through the unconditioned attic.  In this paradigm, there are two major, unnecessary inefficiencies in the system: a larger pump is required to force air around all the curves, and energy is lost due to the large temperature difference between the (frequently leaky) ducts and the unconditioned attic.  Another important theme: just because it is the status quo does not mean that it makes any sense! 

         

        Products and specifics:

        1.      General:

        a.       Look for Energy Star label

        b.      Look for low or zero VOC products

        2.      Lighting:

        a.       Compact fluorescent rather than incandescent

                                                           i.      Larger first cost, but money saved in energy

                                                         ii.      Less heat produced (incandescent: 80% heat, 20% light)

                                                        iii.      Fewer watts required to light the same space

        b.      No recessed lights between conditioned space and unconditioned attic

                                                           i.      Insulation leak

                                                         ii.      New product: air-tight recessed lights, should reduce this problem

        3.      Insulation/sealing/climate control:

        a.       Important to ‘sandwich’ vertical insulation for efficiency

        b.      Seal home as completely as possible

                                                           i.      Dupont House Wrap

                                                         ii.      Requires mechanical ventilation system

        1.      Allows control of intake (location, filter, dehumidify)

        c.       Efficient use of air ducts

                                                           i.      Mastic, not duct tape for sealing

                                                         ii.      Ducts in conditioned space (or condition attic)

                                                        iii.      Minimize turns in ducts

        d.      Don’t forget to insulate behind the bathtub!

        4.      Water:

        a.       Rain water, capture in barrels

                                                           i.      Use for irrigation, commodes

        b.      Point of use/on demand water heating

                                                           i.      Save space (no storage tank)

                                                         ii.      Less piping required

                                                        iii.      Hot water immediately

                                                       iv.      Energy saved (do not heat pipes, or run water while waiting)

        5.      Materials:

        a.       Rastra/Cempo/Perform Wall – blocks made from recycled polystyrene

        b.      Insulated Concrete Form (ICF) construction

        c.       Compressed Straw Walls – for interior

        d.      Hebel Block – aerated cement

        e.       Galvalume Roofing – 30 year roof product

        f.        Sarnafil Membrane roof

         

        We look forward to seeing you at the next Cultivate Green Seminar.

         

        Thanks again,

        Brian Yeoman

         

         

        Anica Landreneau, LEED-AP

        Marketing Coordinator

        Browne Penland McGregor Stephens Architects, Inc.

        520 Post Oak Blvd. Suite 880

        Houston, TX 77027

        713.850.1733 x10

        alandreneau@...

        www.bpmsa.com

         

         

         

         

         



         

      • Environment Associates Architects
        Gary: SolarWall looks to be the very same system you are describing, except it dates from the 1970 s. The corrosion issue for me is this: I am very resource
        Message 3 of 10 , Nov 17, 2004
        • 0 Attachment
          Gary:
           
          SolarWall looks to be the very same system you are describing, except it dates from the 1970's. 
           
          The corrosion issue for me is this:  I am very resource conscious.  I hate waste.  I dislike buildings that, once built, could house people over several generations, but last maybe two generations at best because wholistic considerations for the environment in which they are built were not accounted for.  While I no longer design homes In coastal environments like Pirates Beach and similar places that are that close to the Gulf (due to my personal ethics concerning sustainability issues) (I still do Bay homes) , when I did design homes in these environments, I refused to design wood frame homes in coastal environment unless they used stainless steel or double or triple coated galvanized framing clips and fasteners because of corrosion issues.  Non-stainless steel or un-coated steel fasteners were not allowed on my projects. 
           
          Since concrete is very hydroscopic (i.e., it absorbs moisture very rapidly), the reason I asked if some mesh other than un-coated steel was being used, is that, unless a coating was applied to the shotcrete like you suggested, water penetration to the un-coated steel is an issue,  since as the steel corrodes, it expands, thereby causing the shotcrete to "spall" off over time (by first cracking the shotcrete, this allows more salt laden water to penetrate to accelerate the corrosion and expansion of the steel and the spalling process).  And since coatings on concrete seem to have a very limited life span (and a very limited time where they don't develop appearance problems too if they create some sort of film that is impermeable to water vapor), it would seem like corrosion resistant reinforcing would be highly preferred over un-coated steel in coastal environments.  Otherwise, since the "ICW" system has superior windstorm and storm surge resistance over most other systems, it seems very wasteful not to go a step further with corrosion resistant reinforcing so that the building has the potential to last several generations, rather than about one generation before corrosion really starts to become a problem.  Since the reinforcing is integral to the structure's success to withstand Nature's forces, as it fails from corrosion, so does the entire structure. 
           
          Since I abhor waste, without corrosion resistant reinforcing, it seems to me that this is not a sustainable approach to building in corrosive environments, whereas with corrosion resistant reinforcing, the "ICW" wall system would certainly be a lot greener way to build than most systems being used along the coast today.   Once you get away from coastal conditions, using non-corrosion resistance reinforcing is not much of an issue as long as decent roof overhangs are used to keep exterior walls dry except from occasional blowing rains.   
           
          Hope this helps. 
           
          LaVerne A. Williams, AIA, LEED AP
          architect & building ecologist
          laverne@...
          ENVIRONMENT ASSOCIATES, Architects & Consultants
          5828 Langfield Road
          Houston, TX 77092-1429
          713.528.0000
          866.815.2527 toll free
          www.environmentassoc.com
          30 Years of Leadership in Healthy, High Performance Homes / Green Architecture
          Consulting / Design Counseling / Design / Construction Documents / Construction Administration Services
           
          ----- Original Message -----
          From: Gary Beck
          Sent: Wednesday, November 17, 2004 10:00 AM
          Subject: RE: [hreg] Green Homes 101 - Wall Systems

          Thanks, I had a long flight so I’m reply with more detail.

           

          What is the best a generic name to best describe the system in this photo?  Several manufacturers have supplied this type of panel system. They all have 2 to 4 inch foam cores (1), factory sandwiched between 2" x 2" heavy steel grids (2) which connected by steel truss wires (3), completed with each side getting field applied about 1 ¼ to 1 ½ inches* of shotcrete or gunite (4)  (*minimum of ¾ inches of concrete covering the steel).  

           

          The more recognized “ICF” system (Insulated Concrete Form) describes a ‘concrete-and-rebar-on-the-inside’ system available from many manufacturers. ICF companies are also more prevalent. But for this type of manufacturer panel system, what generic name best describes it?  Maybe use ‘grid wall’, without any caps and without hyphens, or “ICW” for Insulated Concrete Wall (probably also trademarked). 

           

          Trademarks** aside, I agree ‘ICW’ style systems have been around for a while, but unfortunately were skipped in latest IRC-2003 which has added and recognized ICF probably due to prevalence.   This prevalence is probably also since it is basically easier to find companies to pump concrete inside an ICF wall, than it is to find a company to apply concrete or shotcrete to the outside of ‘ICW’ walls.  For ‘ICW’ systems (I like that) I believe the “3D” brand was developed in Austria, but apparently this was after several small US companies made different styles panels and panel manufacturing machines. Besides Mexico (where ICW is also used for roof and deck flooring) and the pockets of projects in the Western US, ICW systems are used more in Austria and Germany where masonry homes are more the norm.  

           

          For a coastal installation, I don’t see how there would be a significant salt air corrosion issue for this type of reinforced concrete system, any more than a wood frame house would have with steel nails.  Nails are about 10 gauge, and while the grid wire in these ‘ICW’ panels is smaller at 12 to 14 gauge, connected by 11 gauge, all steel is fully encapsulated in concrete. All these grid wall systems require a minimum of ¾ inch of concrete OVER the steel grid. The ¾” inside and outside comes from accepted concrete practices, and is probably listed somewhere in ACI or IBC specifications.  After the ¾ inches of concrete, typically masonry paint or similar colored coating system is applied on top of the concrete exterior to provide further water protection. You could probably get a similar added protection by adding polymer plus pigment to the concrete.  

           

          To my thinking the real safety design advantage comes from repetitive application of the steel inside the wall, somewhat similar to a nailed diaphragm wall in wood frame. Having 14 to 12 gauge steel every 2 inches horizontally and vertically on both inside and outside is very repetitive. And for coastal construction, my primary concern is for wind storm resistance for which both ICF and ICW systems outperform everything.

           

          Regarding past projects, I am not familiar with ‘SolarWall’ - is a thermal mass system? The La Porte house I supported used ICW type panels supplied from Ft Worth that were made by original ‘Archer’ machines.  A few years ago I saw a project which used 3D manufactured panels go up on Bissonette near Rice University. I have been told that several area churches have been built from Archer or other ICW panels, one somewhere the west side of town near Alief. I’m sure there are probably 30 to 50 structures in the Houston area which used this type system.  

           

          I like the ICW (or grid wall) type systems for their strength and apparent low installed cost. Cost is always a strong driving force behind any new home building system adoption, and time will tell if ICF and ICW become more broadly adapted. As an engineer, I also support the American Wood Council’s design approaches to High Wind Resistant Wood Frame Construction for anything near the coast. In the low income home in La Porte we applied a high wind wood frame roof system to ICW walls for lowest cost, but the optimal design would use a SIP roof system on ICW or ICF walls. But what can I say? I’m a civil engineer and like the ‘magic mud’ of concrete in all its forms. So I like these quiet, strong, pest resistant and energy efficient ICF/IWC homes, especially in a hurricane.

           

          Gary Beck, P.E.  Tel: 713-530-1950

          Eco-Holdings LLC

          Low Energy and Wind Storm Design

           

          ** PS: I wonder if 2x4™ or Stud™ is owned by Kirby or Weyerhauser?…hmmm

           

          -----Original Message-----
          From: Environment Associates Architects [mailto:laverne@...]
          Sent: Monday, November 15, 2004 11:15 PM
          To:
          hreg@yahoogroups.com
          Subject: Re: [hreg] Green Homes 101 - Wall Systems

           

          Gary:

           

          FYI, there is a trade marked product called GridWall that is similar to Rastra and PerformWall that is manufactured in San Antonio.  So I guess you will have to come up with another name since Amazon Forms One, Inc., probably won't be very enthusiastic about using their Grid-Wall (TM) name for the system you described.  Go to www.AmazonGridwall.com

           

          I'm curious.  What you described sounds very similar to a product called "SolarWall" that I used to build a home I designed in the late 70's.  Nearer the coast, where corrosion from salty air is a real problem, how corrosion resistant is the reinforcing in the system you described? I have to assume that it should be as it is probably galvanized after being welded together.  Is this assumption correct?  Whose system are you actually using for the projects you describe?  Are you familiar with a home built with this "SolarWall" system in the late 70's west of Houston off SH359 between Alt US 90 & Katy?

           

          It is good to know you provide engineering support services.

           

          LaVerne A. Williams, AIA, LEED AP
          architect & building ecologist
          laverne@...
          ENVIRONMENT ASSOCIATES, Architects & Consultants
          5828 Langfield Road
          Houston, TX 77092-1429
          713.528.0000
          866.815.2527 toll free
          www.environmentassoc.com
          30 Years of Leadership in Healthy, High Performance Homes / Green Architecture

          Consulting / Design Counseling / Design / Construction Documents / Construction Administration Services

           

           

          ----- Original Message -----

          From: Gary Beck

          Sent: Monday, November 15, 2004 7:41 PM

          Subject: RE: [hreg] Green Homes 101 - Wall Systems

           

          Finding all these new green and energy efficient sources is more than half the battle!  I can not help with the recessed lighting, but I can help with wall and roof systems and would like to add comments on to the listed wall systems under paragraph 5:

           

          5.      Materials:

          a.       Rastra/Cempo/Perform Wall – blocks made from recycled polystyrene

          b.      Insulated Concrete Form (ICF) and Grid-Wall systems construction

          c.       Compressed Straw Walls – for interior

          d.      Hebel Block – aerated cement

          e.       Galvalume Roofing – 30 year roof product

          f.        Sarnafil Membrane roof

           

          In the listing of green or energy efficient wall building systems, between “a” and “b”, I suggest we should add the term ‘Grid-Wall’. This is my generic name for panels mfrd using steel grids over EPS core.  I became familiar with it last year when I engineered a low income ‘grid-wall’ pilot home in La Porte* (not very pretty but strong and inexpensive).  Now we are finishing a 2nd much nicer contemporary ranch grid-wall design that will soon go up soon nearer to Galveston Bay.

           

          I found that ‘grid-wall’ systems are very common in Mexico and somewhat common in the western US states, probably due with seismic issues. But this high strength also is perfect for Hurricane resistant homes and structures.    Grid-Wall type system has been provided under various names from various manufacturers under names like “3D-Panel”, “Archer-Panel”, “Z-Panel”, “W-Panel”.  I’m sure each mfr will say theirs is different and better, but regardless, all are much stronger than wood frame (3D did a 60,000 lb test load held by one 4’x8’ panel). All 4 systems I have researched appear fairly similar with a basic 2”x2” grid formed from 11 to 14 gauge galvanized steel welded wire rigidly held ¾” off each side of a 2 to 4 inch thick EPS panel core.  4’x8’ panels are field joined and then have 1.5 inches of shotcrete field added and finished to complete the system that is very very strong, termite proof, and very energy efficient.  

           

          Although these grid-walls are not yet common enough to be added into the new IRC 2003 (like the ICF systems), they still may be worth considering since a structural steel material comparison between most of the mfrs panels shows equal or greater steel area per linear foot than what the IRC 2003 requires for ICF construction.  I don’t know what a finished ICF system wall costs per sf of wall surface area, but I was able to help a recent project price the grid-wall at $4/wall-surface-sf installed on a 2500 sf home.  I have to assume that grid-wall costs can become very competitive since the 1.5 inch interior and exterior shotcrete sections is also the reinforced steel structure, so no added cost from covering with hardi-plank, brick, stucco, sheetrock etc. is required.

           

          For those interested in alternate systems like Grid-Wall, ICF, or Wood Frame High Wind Resistant design, ECO can provide engineering and design support.

           

          Gary Beck, P.E.

          Eco-Holdings LLC

          www.eco-holdings.com

          * We put up an info website based around this original LaPorte project called www.stormhaus.com

           

           

          -----Original Message-----
          From: Tom Ritter [mailto:tom@...]
          Sent: Monday, November 15, 2004 11:57 AM
          To:
          hreg@yahoogroups.com
          Subject: RE: [hreg] Green Homes 101 - Native and Water-wise Plants

           

          In the section 2 of the outline below, it mentions not using any recessed lights between conditioned space and the unconditioned attic and says there is a new product of an “air-tight recessed light”.  Does anyone know where I could find this light.  If they are not readily available, does anyone know where I can find insulation “caps” or something similar for my existing recessed lights in the above-mentioned location?

           

          Thanks for any input,


          Tom

           

          2.      Lighting:

          a.       Compact fluorescent rather than incandescent

                                                             i.      Larger first cost, but money saved in energy

                                                           ii.      Less heat produced (incandescent: 80% heat, 20% light)

                                                          iii.      Fewer watts required to light the same space

          b.      No recessed lights between conditioned space and unconditioned attic

                                                             i.      Insulation leak

                                                           ii.      New product: air-tight recessed lights, should reduce this problem

           

           


          From: Anica Landreneau [mailto:alandreneau@...]
          Sent: Monday, November 15, 2004 10:44 AM
          To: sustainable-houston@...; 'HREG'
          Subject: [hreg] Green Homes 101 - Native and Water-wise Plants

           

          RE: Residential Green Building education and training

           

          Dear Concerned Residents

           

          Green Homes 101 sponsored by Cultivate Green and Houston Advanced Research Center (HARC) was a great success.  We hope you will share what you learned and encourage others to participate in future seminars.  We the volunteers of the Cultivate Green program want to thank you for your participation in the Green Homes 101.  Remember that a green home can also be a remodeled dwelling so the possibilities for change are endless.

           

          Due to your interest and feedback from Green Homes 101, our next event will be 12/15/04 from 6:00-9:00pm and will address the use of native and water wise plants as a vital element of green residential development.  Mark Bowen and Charles Tapley will cover theses topics and share their wealth of knowledge concerning regional native plants and how and where to use them. This seminar will also be held at the U of H College of Architecture.

           

          The following is a recap the Green Homes 101 that you attended.

           

          Mike Myers of Aspen Building Systems led a wide ranging discussion of all aspects of what makes a home green as well as what products, materials, design practices, and site considerations do (or do not) go into green home.  Mike opened his conversation by stating a central theme of the evening: all components and systems in a building, and on the site, are (and should be) interconnected; it is a fallacy to consider any single aspect of the building in isolation from all the others.  For this reason, it is best to have as many points of view represented as possible when designing the home.  To demonstrate the problems created by the “design by components” paradigm, Mike brought up the example of ductwork; in most houses, the ducts are added as an unplanned afterthought, and follow contorted paths through the unconditioned attic.  In this paradigm, there are two major, unnecessary inefficiencies in the system: a larger pump is required to force air around all the curves, and energy is lost due to the large temperature difference between the (frequently leaky) ducts and the unconditioned attic.  Another important theme: just because it is the status quo does not mean that it makes any sense! 

           

          Products and specifics:

          1.      General:

          a.       Look for Energy Star label

          b.      Look for low or zero VOC products

          2.      Lighting:

          a.       Compact fluorescent rather than incandescent

                                                             i.      Larger first cost, but money saved in energy

                                                           ii.      Less heat produced (incandescent: 80% heat, 20% light)

                                                          iii.      Fewer watts required to light the same space

          b.      No recessed lights between conditioned space and unconditioned attic

                                                             i.      Insulation leak

                                                           ii.      New product: air-tight recessed lights, should reduce this problem

          3.      Insulation/sealing/climate control:

          a.       Important to ‘sandwich’ vertical insulation for efficiency

          b.      Seal home as completely as possible

                                                             i.      Dupont House Wrap

                                                           ii.      Requires mechanical ventilation system

          1.      Allows control of intake (location, filter, dehumidify)

          c.       Efficient use of air ducts

                                                             i.      Mastic, not duct tape for sealing

                                                           ii.      Ducts in conditioned space (or condition attic)

                                                          iii.      Minimize turns in ducts

          d.      Don’t forget to insulate behind the bathtub!

          4.      Water:

          a.       Rain water, capture in barrels

                                                             i.      Use for irrigation, commodes

          b.      Point of use/on demand water heating

                                                             i.      Save space (no storage tank)

                                                           ii.      Less piping required

                                                          iii.      Hot water immediately

                                                         iv.      Energy saved (do not heat pipes, or run water while waiting)

          5.      Materials:

          a.       Rastra/Cempo/Perform Wall – blocks made from recycled polystyrene

          b.      Insulated Concrete Form (ICF) construction

          c.       Compressed Straw Walls – for interior

          d.      Hebel Block – aerated cement

          e.       Galvalume Roofing – 30 year roof product

          f.        Sarnafil Membrane roof

           

          We look forward to seeing you at the next Cultivate Green Seminar.

           

          Thanks again,

          Brian Yeoman

           

           

          Anica Landreneau, LEED-AP

          Marketing Coordinator

          Browne Penland McGregor Stephens Architects, Inc.

          520 Post Oak Blvd. Suite 880

          Houston, TX 77027

          713.850.1733 x10

          alandreneau@...

          www.bpmsa.com

           

           

           

           

           





        • Gary Beck
          I looked at Amazon which looks like Rastra, both nice systems. I tried to find SolarWall but that name led to a different site for ‘SolarCrete’ Wall system
          Message 4 of 10 , Nov 18, 2004
          • 0 Attachment

            I looked at Amazon which looks like Rastra, both nice systems. I tried to find SolarWall but that name led to a different site for ‘SolarCrete’ Wall system website. It used a fiber reinforced concrete on a much thicker foam core and did not appear to use any steel grid in the concrete.  I also happened to go down Bissonnet near Sheppard the other day and saw the ICW panel home built a few years ago. Don’t stop there but I believe the address is 2111 Bissonnet and can be seen on a drive by. Nice looking, very substantial and contemporary.

             

            Water is can remain present inside even cured concrete, and new moisture will try to go through slabs etc. if given the opportunity to go from higher to lower concentration areas.  Water should not flow through an ICW wall since it has the barrier EPS core – it has no where to go.  But I agree that a finish coating should probably be used to better seal a concrete wall, but this is also preference for a uniform stucco wall color finish so I assume always used.  Also if the concrete were ¼ inch thick, I could see how it might spall. Whereas the reason ¾ inch is an acceptable minimum by most published concrete specifications is to eliminate these types of issues. Thin steel mesh (galvanized and not galvanized) stucco systems are a common system, and while cracking may occur with incorrect application or design, I have not seen where general spalling is an issue. A similar system, but with much lighter steel mesh much nearer the surface is used in gunite swimming pools and spalling does not appear to be an issue. I see no problem with ICW systems where ¾ inch of shotcrete is composited with 14 gauge steel positioned every 2 inches.

             

            I am also a big supporter of sustainable construction (USGBC-LEED accredited etc.) and even more so of low energy consumption buildings. Unfortunately I am learning that sustainability can be many moving targets, and also in the eye of the beholder, or the eye of the supporting industry.  There are so many issues and opinions to consider. One is the long term energy consumption of a wood/fiberglass insulation structure Vs ICF or ICW.  Another is the amount of energy used to produce the higher amount of concrete used in ICF versus ICW. Another can be the use of grown wood versus produced EPS and concrete, or the type of chemical treatments used in treated wood and its effect on ground water. Or the energy and petrochemical processes used just to make styrene in the EPS.  If you prefer ‘pure’ renewables like wood or straw Consider the petroleum used in the fertilizer to grow harvest, process into building components, and transport.  The pesticides used to stop wood eating insects. Or just the sheer volume of new construction wood waste entering capacity limited landfills (Landfills don’t want it!).  One positive thing I did notice on the La Porte project was that ICW system, being panelized 4 x 8 units, has a minimal amount of wall system waste compared to typical wood frame construction.  OSB SIP panels up to 8’x 24’ handle this waste issue even better by leaving most of the waste at the plant. So how to decide?  For many it comes down to cost and in this group personal sustainability preference.  My experience with ICW is that it has great characteristics (strength, energy, pests, sound), is lower in construction waste, and appears to be cost effective at least for smaller simpler home designs.    

             

            What would be absolutely great would be for this group to arrange a Houston tour of a 1/2 dozen “Alternate Construction System Homes” with a probing question poll to each owner on their opinions on durability, cost, time to complete, quality of life, etc.

             

            Gary Beck, P.E.  Tel: 713-530-1950

            Eco-Holdings LLC

            Low Energy and Wind Storm Design

             

            PS: Some references I have come across for anyone wanting to review the structural performance of various ICW panel systems: ICBO Evaluation Service report ER-5154, US Department of Housing and Urban Development  Bulletins #687 and #1120 Rev 1, International Conference of Building Officials Report No. 2440, National Evaluation Service Inc Report No. NER-454.

             

             

             

             

            -----Original Message-----
            From: Environment Associates Architects [mailto:laverne@...]
            Sent: Wednesday, November 17, 2004 9:35 PM
            To: hreg@yahoogroups.com
            Subject: Re: [hreg] Green Homes 101 - Wall Systems

             

            Gary:

             

            SolarWall looks to be the very same system you are describing, except it dates from the 1970's. 

             

            The corrosion issue for me is this:  I am very resource conscious.  I hate waste.  I dislike buildings that, once built, could house people over several generations, but last maybe two generations at best because wholistic considerations for the environment in which they are built were not accounted for.  While I no longer design homes In coastal environments like Pirates Beach and similar places that are that close to the Gulf (due to my personal ethics concerning sustainability issues) (I still do Bay homes) , when I did design homes in these environments, I refused to design wood frame homes in coastal environment unless they used stainless steel or double or triple coated galvanized framing clips and fasteners because of corrosion issues.  Non-stainless steel or un-coated steel fasteners were not allowed on my projects. 

             

            Since concrete is very hydroscopic (i.e., it absorbs moisture very rapidly), the reason I asked if some mesh other than un-coated steel was being used, is that, unless a coating was applied to the shotcrete like you suggested, water penetration to the un-coated steel is an issue,  since as the steel corrodes, it expands, thereby causing the shotcrete to "spall" off over time (by first cracking the shotcrete, this allows more salt laden water to penetrate to accelerate the corrosion and expansion of the steel and the spalling process).  And since coatings on concrete seem to have a very limited life span (and a very limited time where they don't develop appearance problems too if they create some sort of film that is impermeable to water vapor), it would seem like corrosion resistant reinforcing would be highly preferred over un-coated steel in coastal environments.  Otherwise, since the "ICW" system has superior windstorm and storm surge resistance over most other systems, it seems very wasteful not to go a step further with corrosion resistant reinforcing so that the building has the potential to last several generations, rather than about one generation before corrosion really starts to become a problem.  Since the reinforcing is integral to the structure's success to withstand Nature's forces, as it fails from corrosion, so does the entire structure. 

             

            Since I abhor waste, without corrosion resistant reinforcing, it seems to me that this is not a sustainable approach to building in corrosive environments, whereas with corrosion resistant reinforcing, the "ICW" wall system would certainly be a lot greener way to build than most systems being used along the coast today.   Once you get away from coastal conditions, using non-corrosion resistance reinforcing is not much of an issue as long as decent roof overhangs are used to keep exterior walls dry except from occasional blowing rains.   

             

            Hope this helps. 

             

            LaVerne A. Williams, AIA, LEED AP
            architect & building ecologist
            laverne@...
            ENVIRONMENT ASSOCIATES, Architects & Consultants
            5828 Langfield Road
            Houston, TX 77092-1429
            713.528.0000
            866.815.2527 toll free
            www.environmentassoc.com
            30 Years of Leadership in Healthy, High Performance Homes / Green Architecture

            Consulting / Design Counseling / Design / Construction Documents / Construction Administration Services

             

            ----- Original Message -----

            From: Gary Beck

            Sent: Wednesday, November 17, 2004 10:00 AM

            Subject: RE: [hreg] Green Homes 101 - Wall Systems

             

            Thanks, I had a long flight so I’m reply with more detail.

             

            What is the best a generic name to best describe the system in this photo?  Several manufacturers have supplied this type of panel system. They all have 2 to 4 inch foam cores (1), factory sandwiched between 2" x 2" heavy steel grids (2) which connected by steel truss wires (3), completed with each side getting field applied about 1 ¼ to 1 ½ inches* of shotcrete or gunite (4)  (*minimum of ¾ inches of concrete covering the steel).  

             

            The more recognized “ICF” system (Insulated Concrete Form) describes a ‘concrete-and-rebar-on-the-inside’ system available from many manufacturers. ICF companies are also more prevalent. But for this type of manufacturer panel system, what generic name best describes it?  Maybe use ‘grid wall’, without any caps and without hyphens, or “ICW” for Insulated Concrete Wall (probably also trademarked). 

             

            Trademarks** aside, I agree ‘ICW’ style systems have been around for a while, but unfortunately were skipped in latest IRC-2003 which has added and recognized ICF probably due to prevalence.   This prevalence is probably also since it is basically easier to find companies to pump concrete inside an ICF wall, than it is to find a company to apply concrete or shotcrete to the outside of ‘ICW’ walls.  For ‘ICW’ systems (I like that) I believe the “3D” brand was developed in Austria, but apparently this was after several small US companies made different styles panels and panel manufacturing machines. Besides Mexico (where ICW is also used for roof and deck flooring) and the pockets of projects in the Western US, ICW systems are used more in Austria and Germany where masonry homes are more the norm.  

             

            For a coastal installation, I don’t see how there would be a significant salt air corrosion issue for this type of reinforced concrete system, any more than a wood frame house would have with steel nails.  Nails are about 10 gauge, and while the grid wire in these ‘ICW’ panels is smaller at 12 to 14 gauge, connected by 11 gauge, all steel is fully encapsulated in concrete. All these grid wall systems require a minimum of ¾ inch of concrete OVER the steel grid. The ¾” inside and outside comes from accepted concrete practices, and is probably listed somewhere in ACI or IBC specifications.  After the ¾ inches of concrete, typically masonry paint or similar colored coating system is applied on top of the concrete exterior to provide further water protection. You could probably get a similar added protection by adding polymer plus pigment to the concrete.  

             

            To my thinking the real safety design advantage comes from repetitive application of the steel inside the wall, somewhat similar to a nailed diaphragm wall in wood frame. Having 14 to 12 gauge steel every 2 inches horizontally and vertically on both inside and outside is very repetitive. And for coastal construction, my primary concern is for wind storm resistance for which both ICF and ICW systems outperform everything.

             

            Regarding past projects, I am not familiar with ‘SolarWall’ - is a thermal mass system? The La Porte house I supported used ICW type panels supplied from Ft Worth that were made by original ‘Archer’ machines.  A few years ago I saw a project which used 3D manufactured panels go up on Bissonette near Rice University. I have been told that several area churches have been built from Archer or other ICW panels, one somewhere the west side of town near Alief. I’m sure there are probably 30 to 50 structures in the Houston area which used this type system.  

             

            I like the ICW (or grid wall) type systems for their strength and apparent low installed cost. Cost is always a strong driving force behind any new home building system adoption, and time will tell if ICF and ICW become more broadly adapted. As an engineer, I also support the American Wood Council’s design approaches to High Wind Resistant Wood Frame Construction for anything near the coast. In the low income home in La Porte we applied a high wind wood frame roof system to ICW walls for lowest cost, but the optimal design would use a SIP roof system on ICW or ICF walls. But what can I say? I’m a civil engineer and like the ‘magic mud’ of concrete in all its forms. So I like these quiet, strong, pest resistant and energy efficient ICF/IWC homes, especially in a hurricane.

             

            Gary Beck, P.E.  Tel: 713-530-1950

            Eco-Holdings LLC

            Low Energy and Wind Storm Design

             

            ** PS: I wonder if 2x4™ or Stud™ is owned by Kirby or Weyerhauser?…hmmm

             

            -----Original Message-----
            From: Environment Associates Architects [mailto:laverne@...]
            Sent: Monday, November 15, 2004 11:15 PM
            To: hreg@yahoogroups.com
            Subject: Re: [hreg] Green Homes 101 - Wall Systems

             

            Gary:

             

            FYI, there is a trade marked product called GridWall that is similar to Rastra and PerformWall that is manufactured in San Antonio.  So I guess you will have to come up with another name since Amazon Forms One, Inc., probably won't be very enthusiastic about using their Grid-Wall (TM) name for the system you described.  Go to www.AmazonGridwall.com

             

            I'm curious.  What you described sounds very similar to a product called "SolarWall" that I used to build a home I designed in the late 70's.  Nearer the coast, where corrosion from salty air is a real problem, how corrosion resistant is the reinforcing in the system you described? I have to assume that it should be as it is probably galvanized after being welded together.  Is this assumption correct?  Whose system are you actually using for the projects you describe?  Are you familiar with a home built with this "SolarWall" system in the late 70's west of Houston off SH359 between Alt US 90 & Katy?

             

            It is good to know you provide engineering support services.

             

            LaVerne A. Williams, AIA, LEED AP
            architect & building ecologist
            laverne@...
            ENVIRONMENT ASSOCIATES, Architects & Consultants
            5828 Langfield Road
            Houston, TX 77092-1429
            713.528.0000
            866.815.2527 toll free
            www.environmentassoc.com
            30 Years of Leadership in Healthy, High Performance Homes / Green Architecture

            Consulting / Design Counseling / Design / Construction Documents / Construction Administration Services

             

             

            ----- Original Message -----

            From: Gary Beck

            Sent: Monday, November 15, 2004 7:41 PM

            Subject: RE: [hreg] Green Homes 101 - Wall Systems

             

            Finding all these new green and energy efficient sources is more than half the battle!  I can not help with the recessed lighting, but I can help with wall and roof systems and would like to add comments on to the listed wall systems under paragraph 5:

             

            5.      Materials:

            a.       Rastra/Cempo/Perform Wall – blocks made from recycled polystyrene

            b.      Insulated Concrete Form (ICF) and Grid-Wall systems construction

            c.       Compressed Straw Walls – for interior

            d.      Hebel Block – aerated cement

            e.       Galvalume Roofing – 30 year roof product

            f.        Sarnafil Membrane roof

             

            In the listing of green or energy efficient wall building systems, between “a” and “b”, I suggest we should add the term ‘Grid-Wall’. This is my generic name for panels mfrd using steel grids over EPS core.  I became familiar with it last year when I engineered a low income ‘grid-wall’ pilot home in La Porte* (not very pretty but strong and inexpensive).  Now we are finishing a 2nd much nicer contemporary ranch grid-wall design that will soon go up soon nearer to Galveston Bay.

             

            I found that ‘grid-wall’ systems are very common in Mexico and somewhat common in the western US states, probably due with seismic issues. But this high strength also is perfect for Hurricane resistant homes and structures.    Grid-Wall type system has been provided under various names from various manufacturers under names like “3D-Panel”, “Archer-Panel”, “Z-Panel”, “W-Panel”.  I’m sure each mfr will say theirs is different and better, but regardless, all are much stronger than wood frame (3D did a 60,000 lb test load held by one 4’x8’ panel). All 4 systems I have researched appear fairly similar with a basic 2”x2” grid formed from 11 to 14 gauge galvanized steel welded wire rigidly held ¾” off each side of a 2 to 4 inch thick EPS panel core.  4’x8’ panels are field joined and then have 1.5 inches of shotcrete field added and finished to complete the system that is very very strong, termite proof, and very energy efficient.  

             

            Although these grid-walls are not yet common enough to be added into the new IRC 2003 (like the ICF systems), they still may be worth considering since a structural steel material comparison between most of the mfrs panels shows equal or greater steel area per linear foot than what the IRC 2003 requires for ICF construction.  I don’t know what a finished ICF system wall costs per sf of wall surface area, but I was able to help a recent project price the grid-wall at $4/wall-surface-sf installed on a 2500 sf home.  I have to assume that grid-wall costs can become very competitive since the 1.5 inch interior and exterior shotcrete sections is also the reinforced steel structure, so no added cost from covering with hardi-plank, brick, stucco, sheetrock etc. is required.

             

            For those interested in alternate systems like Grid-Wall, ICF, or Wood Frame High Wind Resistant design, ECO can provide engineering and design support.

             

            Gary Beck, P.E.

            Eco-Holdings LLC

            www.eco-holdings.com

            * We put up an info website based around this original LaPorte project called www.stormhaus.com

             

             

            -----Original Message-----
            From: Tom Ritter [mailto:tom@...]
            Sent: Monday, November 15, 2004 11:57 AM
            To: hreg@yahoogroups.com
            Subject: RE: [hreg] Green Homes 101 - Native and Water-wise Plants

             

            In the section 2 of the outline below, it mentions not using any recessed lights between conditioned space and the unconditioned attic and says there is a new product of an “air-tight recessed light”.  Does anyone know where I could find this light.  If they are not readily available, does anyone know where I can find insulation “caps” or something similar for my existing recessed lights in the above-mentioned location?

             

            Thanks for any input,


            Tom

             

            2.      Lighting:

            a.       Compact fluorescent rather than incandescent

                                                               i.      Larger first cost, but money saved in energy

                                                             ii.      Less heat produced (incandescent: 80% heat, 20% light)

                                                            iii.      Fewer watts required to light the same space

            b.      No recessed lights between conditioned space and unconditioned attic

                                                               i.      Insulation leak

                                                             ii.      New product: air-tight recessed lights, should reduce this problem

             

             


            From: Anica Landreneau [mailto:alandreneau@...]
            Sent: Monday, November 15, 2004 10:44 AM
            To: sustainable-houston@...; 'HREG'
            Subject: [hreg] Green Homes 101 - Native and Water-wise Plants

             

            RE: Residential Green Building education and training

             

            Dear Concerned Residents

             

            Green Homes 101 sponsored by Cultivate Green and Houston Advanced Research Center (HARC) was a great success.  We hope you will share what you learned and encourage others to participate in future seminars.  We the volunteers of the Cultivate Green program want to thank you for your participation in the Green Homes 101.  Remember that a green home can also be a remodeled dwelling so the possibilities for change are endless.

             

            Due to your interest and feedback from Green Homes 101, our next event will be 12/15/04 from 6:00-9:00pm and will address the use of native and water wise plants as a vital element of green residential development.  Mark Bowen and Charles Tapley will cover theses topics and share their wealth of knowledge concerning regional native plants and how and where to use them. This seminar will also be held at the U of H College of Architecture.

             

            The following is a recap the Green Homes 101 that you attended.

             

            Mike Myers of Aspen Building Systems led a wide ranging discussion of all aspects of what makes a home green as well as what products, materials, design practices, and site considerations do (or do not) go into green home.  Mike opened his conversation by stating a central theme of the evening: all components and systems in a building, and on the site, are (and should be) interconnected; it is a fallacy to consider any single aspect of the building in isolation from all the others.  For this reason, it is best to have as many points of view represented as possible when designing the home.  To demonstrate the problems created by the “design by components” paradigm, Mike brought up the example of ductwork; in most houses, the ducts are added as an unplanned afterthought, and follow contorted paths through the unconditioned attic.  In this paradigm, there are two major, unnecessary inefficiencies in the system: a larger pump is required to force air around all the curves, and energy is lost due to the large temperature difference between the (frequently leaky) ducts and the unconditioned attic.  Another important theme: just because it is the status quo does not mean that it makes any sense! 

             

            Products and specifics:

            1.      General:

            a.       Look for Energy Star label

            b.      Look for low or zero VOC products

            2.      Lighting:

            a.       Compact fluorescent rather than incandescent

                                                               i.      Larger first cost, but money saved in energy

                                                             ii.      Less heat produced (incandescent: 80% heat, 20% light)

                                                            iii.      Fewer watts required to light the same space

            b.      No recessed lights between conditioned space and unconditioned attic

                                                               i.      Insulation leak

                                                             ii.      New product: air-tight recessed lights, should reduce this problem

            3.      Insulation/sealing/climate control:

            a.       Important to ‘sandwich’ vertical insulation for efficiency

            b.      Seal home as completely as possible

                                                               i.      Dupont House Wrap

                                                             ii.      Requires mechanical ventilation system

            1.      Allows control of intake (location, filter, dehumidify)

            c.       Efficient use of air ducts

                                                               i.      Mastic, not duct tape for sealing

                                                             ii.      Ducts in conditioned space (or condition attic)

                                                            iii.      Minimize turns in ducts

            d.      Don’t forget to insulate behind the bathtub!

            4.      Water:

            a.       Rain water, capture in barrels

                                                               i.      Use for irrigation, commodes

            b.      Point of use/on demand water heating

                                                               i.      Save space (no storage tank)

                                                             ii.      Less piping required

                                                            iii.      Hot water immediately

                                                           iv.      Energy saved (do not heat pipes, or run water while waiting)

            5.      Materials:

            a.       Rastra/Cempo/Perform Wall – blocks made from recycled polystyrene

            b.      Insulated Concrete Form (ICF) construction

            c.       Compressed Straw Walls – for interior

            d.      Hebel Block – aerated cement

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