Rigid Insulation Below Concrete Slab

In climate zones 4 and 5 the code requires certain slabs below grade slabs that are less than 12 in.

Rigid insulation below concrete slab.

Eps 3 xps 2 faced or unfaced. For under slab applications the rigid foam insulation typically should be installed over a gravel base with a poly vapor diffusion retarder between the gravel and insulation. For installation on concrete foundations and under floor slabs the rigid foam insulation you choose can make a difference of tens of thousands of dollars on a project. Horizontal insulation placed less than 12 inches below the ground surface or that portion of horizontal insulation extending outward more than 24 inches from the foundation edge should be protected against damage by use of a concrete slab or asphalt paving on the ground surface directly above the insulation or by cementitious board plywood.

R 7 7 rigid foam insulation model 310891 18 35 18 35. A careful evaluation of these materials performance attributes against the project s needs can dramatically shrink labor and material costs. Below grade under slab system with foamular rigid board insulation. If the slab has hydronic tubing the minimum r value of this insulation increases to r 15.

One of the best ways to save money on rigid foam insulation installed under concrete slabs is to ensure the material is not over engineered. 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. Slab is one foot or less below grade r 10 insulation required extending 2 feet below grade for climate zones 4 and 5 4 feet below grade for climate zone 6 insulation should extend downward from the top of the slab with two options to reduce slab edge insulation r value exterior slab insulation must be protected 46. Where the heating is likely to be turned on and off such as in new build domestic properties and a faster thermal response is required the floating floor arrangement of.

Concrete 4 existing drywall 2 plywood 5 wood 3 sheathing type. Additional insulation is applied along the edges of the slab because that is a primary surface for heat loss. Their researchers found that xps insulation installed below grade for 15 years had absorbed 67 percent or more moisture. Target an appropriate compressive strength.

Don t worry if the concrete contractors put a few holes in the poly. Insulation below the slab suits continuous low level heating gradually warming the thermal mass of the concrete and sustaining it at a consistent temperature. Owens corning enclosure solutions.