Construction Design-Using Fibrous Sub-Slab Insulation with In-Floor Heat

I’ve written about sub-slab insulation and heated floors several times over the past couple years, this post is about something I’ve been thinking about for a while now, using a fibrous insulation, like Rockwool’s ComfortBoard 80 or 110 under a concrete slab with hot water heat.  The questions I had about this strategy are one, will there be an issue with compression of the insulation when concrete is poured over the product?  And two, will a staple be able to hold the hot water tubing in place?

Rockwool ComfortBoard being installed below a concrete slab.  Photo by Travis Brungardt

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Construction Design-Closed Cell Spray Foam Below a Slab

This post originally appeared on GreenBuildingAdvisor – Green Building Advisor is the one-stop source for builders, remodelers, architects & homeowners looking for expert advice on green products, strategies & proven construction details.

I was introduced to using closed cell spray foam (CCSF) below a slab a few years ago by New England contractor Wade Paquin of WKP Construction. He was insulating the below grade slabs of his new homes by spraying a couple inches over a bed of stone, then pouring the concrete. I have now had the opportunity to try this insulation method over a couple projects, Continue reading “Construction Design-Closed Cell Spray Foam Below a Slab”

Building Science-A Benefit of Exterior Insulation

I’m a big fan of exterior insulation.  It’s rarely used in my area, mostly because the State of Minnesota has eliminated that code requirement.  It has to to with our wide use of polyethylene sheeting as a vapor retarder on the warm in winter side of a wall assembly and then adding a low permeance plastic insulation product as exterior insulation.  These plastic foams would be the choice for most contractors, lower cost and easy to source.  Very slow vapor movement in either direction when a wall assembly becomes wet.  This posting isn’t going to get into the foam insulations, but more into what exterior insulation can do for a home. Continue reading “Building Science-A Benefit of Exterior Insulation”