Alternative Wall Construction
From: Charles Ehrlich (chasinnernet.com)
Date: Fri, 14 Oct 94 01:13 CDT
I've recently completed some research on alternative building
products (walls) and techniques.  As it seems there is quite 
a bit of interest in energy efficiency in this group, and because 
I'd like to expand my list, I present it to you here.  Apologies
in advance for the poor formatting.

This is a list of my preferred alternative building products
and methods, mostly for walls, in order of my personal preference.

InteGrid Building Systems
J. Gregory Otto, President
1396 Campus Drive
Berkeley, CA  94708
(510) 845-1100 Phone
(510) 845-6886 FAX
10" thick by 10' long prefab polystyrene and concrete units 
can be cut into 15" by 15" blocks. End caps for wall openings.
Entire wall is assembled and held in place with epoxy while 
steel reinforcing is positioned.  Concrete poured into the
core of units for entire wall at once forming an internal
post-and-beam construction, flexible and strong.
R-24 thermal insulation
53dB sound reduction
Two hour fire rating by U.L. at 1920 degrees
UBC compliance
Does not wick water, but not water proof
Stucco and tile can be directly applied to the wall
Pest-proof
Structural strength of a 5-3/8" poured wall
86% recycled, post-consumer, polystyrene by volume
Construction costs equivalent to 6" stud frame construction.
Engineer must be consulted for three story structures or over.

InSteel Construction Systems, Inc.
2610 Sidney Lanier Drive
Brunswick, GA  31525
(912) 264-3772 Phone
(800) 545-3181 Phone
(912) 264-3774 FAX
Panels of polystyrene and steel mesh 4' wide by reasonable 
length in 8" increments, can be cut in field.
Final construction is two layers of Shotcrete (sprayed on)
surrounding core of polystyrene forming a "space frame"
Made from recycled steel (not from recycled polystyrene)
CABO 1 and 2 story dwelling compliance
HUD compliance
Excellent thermal and sound barrier (no specifics given)
Excellent thermal mass characteristics.

Structural Insulated Panel Association
1511 K. Street, NW Suite 600
Washington, DC  20005
(202) 347-7800
See also Progressive Architecture, Nov. 1993
A specific mfgr:
Better Building Systems
418 Broad Street
Nevada City, CA  95959
(800) 200-2794 Phone
(916) 265-2794 Phone
(916) 265-9349 Fax
The general beast is a stressed panel of wood, sometimes
made of post manufacturing byproducts adhered to a core
of insulating material like polystyrene or expanded
polystyrene.  Thickness vary.
Units usually ordered pre-cut for wall openings
R-24 to R-35
More costly than traditional building methods
Good load bearing and shear strength.
Good for roofs because it spans well requires fewer joists.

Steel framing is also considered an alternative building
material and its popluarity is growing rapidly because of
the easy with which it can replace traditional "stick"
framing methods.
I personally have strong reservations because of the very
poor thermal charactericstics which must be mitigated with
external thermal sheathing thereby greatly increasing the
cost and complications in construction.  From the Calif.
Energy Commission:

New 1995 Residential Standards
Steel frame structures must show equivalence to wood frame
structures for meeting mandatory envelope (floor, walls,
roof/ceiling) insulation requirements.  (This is a
clarification of intent for those CA builders who don't
care about having livable homes).

Table B-2: Framed wall assembly R-values
Framing Type      Cavity     Sheathing   Wood Frame   Metal
                  R-Value    R-Value     U-Value      U-Value
2x4 @ 16" O.C.    R-11       -none-      10.8         3.46
                  R-11       8           18.8         13.3
2x4 @ 16" O.C.    R-13       -none-      11.9         5.50
                  R-13       2           13.8         7.46
                  R-13       4           15.8         9.52
                  R-13       6           17.9         11.5
.               R-13       8           20.8         13.5

The table continues, but I think this makes it pretty clear.
I could think of no better way to throw away insulation than
by building a building with steel studs.

Don't believe a steel framing salesperson.  There are very
few bona-fide tests showing any methods of insulating steel 
studs that match the insulative value of wood studs.

The last alternative is called "Engineered wall framing"
system (EWF) and was tested by PG&E's Research and Developmnt
department under the ACT Squared project.  With this method,
"Oriented Strand Wood" products replace timber as the main
structural building member.  Oriented Strand wood is made
from pieces of wood cut from small, fast-growing trees and
other wood milling by-products.  The wood is stripped, 
embued with polyurethane resin and press formed into sheets
up to 35 feet long, 5-1/2" thick and 8 feet wide.  It can
then be sawed into narrow boards.

These OSW boards are much stronger than timber and a modified
framing systems reduce the thermal conductivity of the wall
construction by reducing the area of conductive paths through
the non-insulated parts of the wall.  A traditional timber
stud wall has 35% wood/wall ratio while the EWF wall has only
a 9% wood/wall ratio.  The method also requires less material
due to increased spacing between vertical members and the
ability to omit a double-top plate which offsets the higher 
price of OSW.  It does not shrink or warp.

Some argue that steel stud walls, to be thermally competitive 
with wood stud walls, need to be built in a similar manner.  
The problem with either OSW or Steel stud engineered walls is 
that contractors are affraid of these new methods and building
inspectors aren't going to know anything about them either.

If it isn't obvious, I'm quite excited about the Integrid
product I mentioned first.  No other alternative building
products have the U.L. fire rating.  None match the structural
strengh (except perhaps Insteel).  The product has been used
in Europe for a number of years.  Contractors and inspectors
are more apt to accept Integrid becasue of its similarity to
traditional CMU (Concrete Masonry Units).  

I met with the president today and I think he has a great product.
I am, however, in no way affiliated with them.

These are my own opinions and do not represent an endorsement
or reccommendation of these products by me or my employer.

-Chas
chas [at] innernet.com


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