Building Envelope

Stuart Fix wrote:

George Hawirko wrote:Since PH are so air tight, stupid mistakes in construction using wood will almost always give you mold/mould and rot, so any savings using wood, witch are zip,, will also always cost you more

This unavoidable rot issue might be more prevalent in BC where you are, but on the Prairies and many other areas, it simply isn't an issue. Regardless, good design following building science principles should eliminate rot/mold issues. I agree you have an exciting product, with structural EPS, but I think we'll have to agree to disagree for the time being on the long term sustainability of whole home EPS vs. lumber construction. I'd love to see some LCA data on the product you're using. Have you thought of contacting the ATHENA Institute to get this done?

I agree with Stuart on his point about the relationship b/w geographic location and prevalence of wood rot/mold.  I live in Saskatchewan, and have upgraded many residential building envelops in homes > 70 years old.  The only vapor barrier these homes have are multiple coats of paint on the walls and lots of organic matter, like sawdust and paper, in the walls for insulation, a good recipe for moisture damage & rot.  However, as our relative humidity is so low, I have yet to witness even mild-moderate moisture damage, with exception to poorly maintained & ventilated shower surrounds, plumbing systems & poorly ventilated bathrooms.  In my region, I am confident in stating that careful design and building practices can prevent mold/rot and ensure building longevity.