[Ferro List] 3 questions for Walter

[Keith B]

Hi Walter,

Any more details on what you are planning for your "insulating concrete 
layer"?  At 40 pcf for an all mineral lightweight mix, I would expect a 
thermal performance of R1 plus or minus a bit, but authoritative data 
seems notably lacking in the area.  Further, vermiculite or perlite 
mixes generally end up very porous, so I presume you are relying on your 
hard skin for waterproofing, but is there a risk of internal 
condensation build up in your coldest weather?  I ask because I've 
recently been reading a paper on an exotic system which suggests that 
one may be able to do better, both thermally and regarding permeability 
and water storage, with an OPC one.

kb

Walter Jeffries wrote:
> . We still need to do the insulating layer on the cottage roof  
> and then the final hard coat. That is a project for this summer.
>
> Here's a link to a model, ...insulating concrete layer over the roof...
>
> http://sugarmtnfarm.com/blog/2007/09/dog-house-bottles-roof.html
>