Floor Slab Insulation Thickness

Slab on grade floors with a floor surface less than 12 inches below grade should be insulated in accordance with information provided in the insulation and fenestration requirements by component table which is reproduced following this paragraph.

Floor slab insulation thickness. Insulation sheets should be laid tightly together with the joints staggered to avoid movement. 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. Insulation below the floor slab. 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.

There will be a damp proof membrane under the insulation and possibly a second membrane on top depending on the type of screed. 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. If the insulation is installed below the slab the thermal capacity of the building is increased helping to maintain steady internal temperatures. 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.

Get free shipping on qualified under slab foam board insulation or buy online pick up in store today in the. 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. Protect the exposed top of the perimeter insulation from any damage until covered by skirting or wall finish. Insulation is placed below the concrete floor slab.

Insulation requirements for slab on grade floors can be found in section r402 2 9 of the 2012 iecc and section n1102 2 9 of the 2012 irc. 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 is laid on the concrete and covered with a screed. Both codes state slab edge insulation is not required in jurisdictions designated by the building official as having a very heavy termite infestation.

Where insulation is positioned above the slab the slab and dpm can be installed either way round. Product thickness in 2 in 2 1 5 in 1 2 375 in 1 3 in 1 insulation location. 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.