posted 8 years ago
I've wondered about the expense of perlite. I've yet to research it. Asbestos free vermiculite might be another option; so might cinders from a local volcano.
If you go cinder, I'd look into those places that I mentioned, unless you find another volcano closer.
What happens to lime on horizontal surfaces? Does it break up?
It takes a long time to carbonate at decent thickness. It can break up depending on traffic. You said garage and basement, i like durability there. Its akin to a softwood pine floor, when there are more durable materials more suitable for a floor.
Does lime adhere to cinder block substrates?
Like a dream. The reason why modern Masons add lime to their Portland mortar (besides stamped prints) is because mainly of its plastic, sticky, workable properties. I'm still scraping it off my Glass
That is an interesting idea about laying pavers on Pumice/ scoria. Do you stabilize these materials in any way? Are the pavers laid dry or mortared?
I typically like screed cinder subfloors loose for maximum r value, ease of use, sustainability, etc. I've laid good brick tight and dry, irregulars mortared, big wood and concrete pavers with Adobe grout, and flagstone laid dry with mortar grout.
I've used some rock wood bats. It is supposed to resist mold. The reason I'm worried about any bat material, or any modular material for that matter, is that air can infiltrate around seams and contact a cold wall, forming a little condensation spring. Though I suppose I could plaster really well to keep cracks down.
Lay it tight and there are no gaps. A render is airtight.
Where do you get the salvaged rigid insulation? Is it from demolitions?
I suggested craigslist earlier since you live in the big city. You could also try commercial roofing companies when they do tear offs and apply new membrane. Or repurposed materials. They're up there too.
You'd think that here in dry Colorado, mold would be the least of my worries! But not only am I having to gut my house, but many of my friends are doing the same. These neighborhoods were post WWII building boom areas, and I think quality control suffered.
Detail that moisture well. In an uninsulated basement, gutter, drain away from foundation, vent appliances correctly. If you have larger basement moisture problems, I don't know your situation.
The new crop of blowing agents in spray foam is much more sustainable. I know you likely want to use more inert for your families sensitivities, but I was impressed with a basement Spray job that I saw. Is there à MgO airKrete company out there?
If this basement doesn't include bedrooms and family rooms, does it make more sense to just better insulate it's ceiling for the rest of the house? If so, then you could Lime wash or skim the block for piece of mind and aesthetics and devote your resources to other projects.