Concrete Slab Foam Insulation

Spray foam for sure has uses where it is the best choice by a long shot but under a slab is not the place.

Concrete slab foam insulation.

Polylevel uses a high density polyurethane foam to fill voids and stabilize and lift sinking concrete slabs. Does the order of the. For more information on this issue see choosing rigid foam. With the soil no longer supporting the slab the concrete will sink creating an uneven surface.

As soil underneath a concrete slab shrinks settles or washes away this leaves empty space or voids beneath the slab. They both come in various rated compressive strengths from 10 psi to about 80 psi. Geolift works for driveways sidewalks patios garage floors even pool decks. Concrete 4 existing drywall 2 plywood 5 wood 3 sheathing type.

Of these two materials green builders prefer eps because eps is manufactured with a more environmentally benign blowing agent than xps. When building a slab on grade eps rigid foam insulation is the most common choice of insulation for performance and cost. Geolift can help to lift existing concrete surfaces and fix those problem areas around your house with much less labor. Foamular does not absorb water like other types of foam board which makes it ideal for below grade and under slab installations.

Finally some contractors in cold climates began installing a continuous horizontal layer of rigid foam insulation under their concrete slabs. The most common insulation materials for use under a concrete slab are extruded polystyrene xps and expanded polystyrene eps. Xps and eps rigid insulation is used under concrete slabs. 40 psi x 8 wide tire x 12 long tire print 3 840 lbs.

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. Say you use an average and relatively inexpensive rating of 40 psi then the insulation will support. Of the slab s total heat loss certainteed effect of slab edge insulation rem design simulations 8 increase in total heating consumption with no slab edge insulation 62 of heat loss through slab edge 16 insulation located below grade shall be extended the distance provided in table 402 1 1. Many builders bevel the top of the vertical insulation so that none of the rigid foam is visible after the concrete slab is placed.

Foamular 250 foam board. Eps 3 xps 2 faced or unfaced. The foam layer isolates the room temperature slab from the cold soil under the slab. Home depot does sell the right solution for residential concrete slab insulation.

R 5 78 rigid foam insulation model 320817 14 68. At this point we ve got a sandwich with three or four layers and the question arises. Foamular provides r 5 per inch of thickness winter and summer.