Insulation Under Concrete Slab Roof

The concrete deck can offer greater speed of roof construction which is an important consideration on many larger commercial projects.

Insulation under concrete slab roof.

In cold climates it is advisable to use a minimum of 2 inches of extruded polystyrene under the slab. Perimeter slab insulation should cover as much of the exposed concrete as allowed by code. Slabs that include embedded hydronic tubing for radiant heat always need a continuous layer of horizontal insulation under the entire slab. Ecofoil under slab insulation consists of a layer of metalized foil centered between a layer of bubble insulation laminated to each side with a permanent bond.

Slab edge may be responsible for about 60 of the slab s total heat loss certainteed effect of slab edge insulation rem design simulations 8 increase in total heating consumption with no slab edge insulation 62 of heat loss through slab edge 16. Creating a void between the old ceiling and new is better but ideally you need to eventually consider insulating the top of the concrete roof with solid insulation and a better covering grp or epdm. Historically used as a stable roof insulation eps has gained wide acceptance in wall below grade and under slab applications due to its low moisture absorption strength and stable long term thermal performance. Eps insulation blocks can be custom cut into a variety of shapes and sizes to meet wide ranging job specifications.

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. Designers generally insulate both directly under the slab and around the perimeter as well. Flat concrete roofs are generally not ventilated since the ceiling internally is generally a plaster and skim coat directly to the underside of the cold concrete. The reflectix concrete slab insulation is an innovative easy to handle product that increases the energy efficiency of radiant floor and snow melt systems under concrete.

120 25 infrastop 48 x 125 under concrete slab reflective layered bubble foil insulation. It can be tempting to cut the insulation at ground level to avoid seeing it but this creates an area for heat to move in or out of the home and there will be heat loss through the floor and foundation if not fully insulated. Many increase the under slab insulating foam board thickness to 3 or 4 inches at the outer 2 to 4 feet of the slab. A continuous layer of horizontal insulation reduces heat loss in the winter and it reduces condensation of humid air on the slab during the summer.