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.

Insulation under concrete roof. 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. The foil within the product acts to spread out the heat signature of the heating coils. 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.

Concrete contractors learned that a layer of poly helps to keep a slab dry because it stops upward vapor diffusion from the soil. Eventually polyethylene was invented. Using the correct insulation and correct detailing thickness is the only way of guaranteeing zero condensation. In most cases the attic is ventilated and the infiltration barrier is the drywall ceiling.

In this case the insulation must lie directly on top of the ceiling. 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. Finally some contractors in cold climates began installing a continuous horizontal layer of rigid foam insulation under their concrete slabs. The concrete deck can offer greater speed of roof construction which is an important consideration on many larger commercial projects.

California roofing requirements under the california residential code cover everything from what suitable materials to use to requirements for roof coverings to roof insulation. There are also provisions for fire classification weather protection re roofing roof drainage and solar power. 129 50 infrastop 48 x 50 under concrete slab reflective layered bubble foil insulation. 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.

It provides an r value of 4 per inch of thickness and is the cheapest type of foam board insulation.