Best Insulation Over Concrete Slab

Yet expanded polystyrene eps performs as well or better than xps and at a substantially lower cost.

Best insulation over concrete slab.

One option for insulating on top of a slab is to apply rigid foam insulation directly to the slab then install the subfloor on top of the insulation. If your basement slab lacks sub slab foam you ll have to install the insulation above the slab. When building a slab on grade eps rigid foam insulation is the most common choice of insulation for performance and cost. Foamular does not absorb water like other types of foam board which makes it ideal for below grade and under slab installations.

If the slab has hydronic tubing the minimum r value of this insulation increases to r 15. Use a good quality foam board adhesive to adhere the foam to the concrete. We recommend at least 1 inch of foam board. Foamular provides r 5 per inch of thickness winter and summer.

I wouldn t go as far as saying you couldn t use spray foam below a slab but i m not sure why you d want to. In climate zones 4 and 5 the code requires certain slabs below grade slabs that are less than 12 in. Allow this to dry then roll out 6 mil polyethylene sheeting over the floor to provide moisture protection. Home depot does sell the right solution for residential concrete slab insulation.

This method is simple but it has. When it comes to concrete and insulation contractors tend to be most familiar with extruded polystyrene xps. 4 where rainfall can be heavy use a fine tooth trowel to apply cold cut back asphalt mastic over the entire slab use about one gallon per 100 square feet of floor. Foamular 250 foam board.

Tim healeyinstead of a conventional sleeper system to support the subflooring an uninterrupted layer of foam sits directly on top of the concrete slab. There are several ways to install subflooring above the rigid foam. Below grade to have r 10 vertical insulation at the slab perimeter extending downward from the top of the slab to a depth of at least 2 ft. Two layers of 3 4 inch osb subflooring then float unattached on top of the foam to provide a solid and stable underpinning for the wide board wood floors.