[Greenbuilding] [BULK] Re: VIroc

[Chris Green]

Keith Winston wrote:
> Chris: EIFS means Exterior Insulation and Finish Systems: they are 
> used on big box stores, indeed probably the majority of large 
> commercial jobs. 
I had a look around and see these systems resulted in a lot of class 
action lawsuits, especially in Georgia. I found this comment in the 
NACHI forum archives from Sept. 2005 from Dan Bowers, a certified home 
inspector from Mission, KS :
> We did 127 stucco or EIFS inspections in 4 months. We found 2 houses 
> that had the EIFS, stucco or architectural details installed correctly.
Source:
http://www.nachi.org/bbsystem/viewtopic.php?p=161727

The inspections were carried out mostly in the Kansas and MO area in the 
summer of 2005. These were houses 4 to 6 years old, I believe from 
following the discussion. 2 properly installed EIFS systems out of 127 
is not a good track record.  The track record for the installations is, 
I hope, a lot better.
> They consist of foam applied to the outside of the shell, with some 
> kind of synthetic plaster applied on top of that. They are prone to 
> problems if not properly detailed, but they are done very very 
> frequently now so I assume they've ironed out a lot of the early problems.
It doesn't appear to be the case. At least for residential applications.
> They aren't particularly green in my book, except for potentially 
> creating a tight well-insulated wall. In principle you might finish 
> them with a natural plaster or something, but you're probably 
> increasing the chance of some kind of failure. I often prescribe a 
> foam layer applied under siding to make up for poor insulation in a 
> rehab, so I'm 1/2 the way to an EIFS...
For a house I worked on this fall, it was decided to install foam boards 
on the exterior with another sheet of ply on the outside, creating 
something like a DIY non-structural SIPS panel. The building inspection 
department guys had a meeting about this and subsequently ordered that 
we drill1" holes through the assembly in each stud cavity to let any 
moisture that got in from inside the building escape (we live in a dry 
desert so most of thee water is from inside the house). Being the low 
man on the totem pole, I got the job and drilled something like 120-140 
holes one morning with an auger bit*. I calculated there is about 98 sq. 
inches of holes through the walls.
>
> I think one thing we fall into as green builders is a heightened level 
> of attention on materials and implications, but reduced attention in 
> some cases to basic building detailing. One of my biggest concerns 
> about straw bale building, for example, is that I think it's hard to 
> get the details right (at least here in DC, high summer humidity and 
> periodic driving rains). I agree with those that rated longevity as an 
> important green characteristic. 
I'm quite partial to SB building and agree that proper detailing is the 
key to good construction, not only for SB but the other methods as 
well.. Each environment and microclimate poses different challenges, so 
each new SB building is another living and inhabited laboratory. Thanks 
to the internet, and the willingness to share knowledge, the technology 
is maturing quite rapidly.
Some people are discussing ways to install temperature and moisture 
sensors inside the walls of the houses and collect the data from them in 
a central data base for analysis.. I guess you could say this is the 
left-brained side of SB building... :-)

Have you explored the prefabricated straw bale wall system that the 
folks at GenX Systems have developed?
Their method is to prefabricate the wall panels inside a shop and under 
controlled (dry) conditions, then take the panels to the building site 
and do a tilt-up installation. The panels can either be infill or load 
bearing, I believe.  I think this method has a lot of promise. It should 
be a lot easier to keep a tight watch on the detailing. Such a system 
means a very quick installation schedule and therefore you're not so 
vulnerable to local weather problems, and this in turn lengthens the 
optimum construction season.
It's worth exploring.
http://www.genxsystems.com/

Come to think of it, a lot of things are worth exploring. We're on an 
adventure here.

Cheers,

Chris Green.