Floor Slab Insulation Thickness

Insulation is laid on the concrete and covered with a screed.

Floor slab insulation thickness.

There are fewer restrictions on the thickness of the insulation in comparison with above slab insulation and there is less of an issue with point loading as the load is spread over the slab rather than the insulation. Insulation sheets should be laid tightly together with the joints staggered to avoid movement. The insulation is then laid followed by a polythene separating layer and either a concrete screed or tongue and groove chipboard ready to receive the specified floor finish. 2x4 wall 2 2x6 wall 2 attic 2 basement 3 crawlspace 2 exterior sheathing 3 exterior wall foundation 4 floor 1 garage 3 under slab.

Both codes state slab edge insulation is not required in jurisdictions designated by the building official as having a very heavy termite infestation. Lightweight rigid polyisocyanurate pir foam insulation boards such. If the insulation is installed below the slab the thermal capacity of the building is increased helping to maintain steady internal temperatures. 2015 iecc irc section r402 2 10 n1102 2 10 slab on grade floors.

Ground bearing floors can include insulation either below or above the concrete slab the choice the designer makes will have an impact on the temperatures inside the building as follows. There will be a damp proof membrane under the insulation and possibly a second membrane on top depending on the type of screed. Protect the exposed top of the perimeter insulation from any damage until covered by skirting or wall finish. Product thickness in 2 in 2 1 5 in 1 2 375 in 1 3 in 1 insulation location.

Insulation is placed below the concrete floor slab. The edge insulation should be at least 25mm thick and height should extend from the top of the concrete slab to the top of the finished floor screed. In this scenario a rigid foam insulation is usual and as you d want the same u value in the roof we need the same thickness of insulation 180mm. 4 10 2012 3 climate zones e301 1 6 5 8 4 slab r value table 402 1 1 insulation and fenestration requirements by component e402 1 1 climatezone slab r valued 4 10 2 ft 5 10 2 ft 6 10 4 ft 9.

A 50mm thick layer of proprietary floor slab insulation is usually enough to reach and maintain the target u value but this should be checked with an architect first. Where insulation is positioned above the slab the slab and dpm can be installed either way round. Insulation below the floor slab.