How To Insulate A Concrete Slab Roof

Flat roofs with a concrete deck are more commonly found in commercial buildings than domestic builds which are typically built with timber deck construction.

How to insulate a concrete slab roof. This is for a house with an r 11 insulated slab. This will help in two ways. Up to 80 of heat loss in a floor slab occurs around the edges. A second solution would have been placing the slab and then building a sleeper system on top of it to support the floor.

After placing the headers and tubes at over the slab pave the roof slab ensure all tubes are placed well and compact with concrete mixture so that after paving the roof will look like a normal concrete floor. The concrete deck can offer greater speed of roof construction which is an important consideration on many larger commercial projects. The air gap in the tubes will act a insulation since heat travel through air will be less. The chart above is from a house with r 19 walls and an r 40 roof.

One solution would have been installing rigid insulation under the slab turning it up on the perimeter to form a giant pan and then casting the concrete slab inside the pan. Continuous insulation is applied directly to the underside of the slab and extends inward horizontally from the perimeter for the distance specified or continuous insulation is applied downward from the top of the slab and then extends horizontally to the interior or the exterior from the perimeter for the distance specified. Check out the btu loss through the un insulated concrete slab on this house. The area between the stemwalls is usually filled with compacted gravel to support the slab.

As we build better that slab becomes a larger of the loss of heat. Because they are easier to insulate slab foundations with stemwalls are preferable to monolithic slabs. At a minimum this type of foundation requires vertical perimeter insulation to separate the slab from the stemwall. The first thing to consider when looking into different types of concrete floors is why it s so important to insulate the floor slab.