Insulation Under Concrete Roof

This foam board insulation is the rigid pink or blue panels that can be found at home centers in many different thicknesses.

Insulation under concrete roof.

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. Concrete contractors learned that a layer of poly helps to keep a slab dry because it stops upward vapor diffusion from the soil. It provides an r value of 4 per inch of thickness and is the cheapest type of foam board insulation. Using the correct insulation and correct detailing thickness is the only way of guaranteeing zero condensation.

State applicable energy ashrae zone minimum r value state local ms mississippi ashrae 90 1 2010 2 r 20 3 r 20 state local mo missouri 2012 iecc 4 r 25 5 r 25 state only mt montana 2012 iecc 6 r 30. In this case the insulation must lie directly on top of the ceiling. The concrete deck can offer greater speed of roof construction which is an important consideration on many larger commercial projects. 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.

Eps is used under roofing over foundation walls and beneath siding. Infrastop 48 x 125 under concrete slab reflective layered bubble foil insulation 140 00 as low as. Minimum insulation r value requirements non residential above roof deck. Roof ceiling insulation insulation in roof ceiling constructions must be placed in direct contact with the infiltration barrier.

In most cases the attic is ventilated and the infiltration barrier is the drywall ceiling. 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. There are also provisions for fire classification weather protection re roofing roof drainage and solar power. Finally some contractors in cold climates began installing a continuous horizontal layer of rigid foam insulation under their concrete slabs.

The foil within the product acts to spread out the heat signature of the heating coils.