How To Insulate A Concrete Slab Roof

Check out this article for a list of slab edge insulation solutions and episode 125 for my interview with henry edney of maxraft.

How to insulate a concrete slab roof. 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. This will help in two ways. To insulate a flat roof with a concrete deck we recommend a warm deck construction method where the vapour control layer is sandwiched between the concrete deck and a layer of rigid pir insulation boards. 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. Flat roofs with a concrete deck are more commonly found in commercial buildings than domestic builds which are typically built with timber deck construction. Check out the btu loss through the un insulated concrete slab on this house. The air gap in the tubes will act a insulation since heat travel through air will be less.

A second solution would have been placing the slab and then building a sleeper system on top of it to support the floor. Perimeter slab insulation heat loss through an insulated slab windows 33 roof ceiling 8 slab 15 6 doors 5 walls 39 insulation and fenestration criteria table 402 1 1 insulation and fenestration requirements by componenta climate zone fenestration u factorb skylightb u factor glazed fenestrationb e shgc ceiling r value wood frame wall r value. The first thing to consider when looking into different types of concrete floors is why it s so important to insulate the floor slab. 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.

This is for a house with an r 11 insulated slab. As we build better that slab becomes a larger of the loss of heat. At a minimum this type of foundation requires vertical perimeter insulation to separate the slab from the stemwall. Because they are easier to insulate slab foundations with stemwalls are preferable to monolithic slabs.