Residential Flat Roof Insulation

The type that is right for your flat roof insulation job depends upon the state of the roof expert opinion on the best type and your budget.

Residential flat roof insulation.

Rockwool stone wool roof insulation combines the thermal performance dimensional stability impact resistance and acoustic control required to increase the performance of many flat roof assemblies. In climate zone 5 the prescriptive table of the international residential code requires at least r 49 of ceiling insulation. With a flat roof however this becomes a major concern. That accounts for its materials membrane insulation and decking as well as snow and rainfall and even for equipment like an air conditioner.

Different types of roofing insulation exist including blanket insulation blown insulation and rigid insulation. The roof is only four years old so removing it is not an option he says ruling out a layer of exterior rigid foam. Better to have 3 or more. Pros and cons for flat roof materials all three types of flat roofing cost 250 to 350 per square 100 square feet but prices vary according to region and size of the roof.

The target should be to achieve a u value of 0 25w m2k or better. From there the flat roof system you choose will determine the materials you apply. These products provide a high r value inch excellent sound attenuation characteristics and outstanding fire performance. To achieve this add 100 to 160mm of insulation above the structural deck dependant upon insulant conductivity.

Flat roofs usually come with a 10 to 20 year warranty but can last 25 years if you build the roofs right and maintain them using commonsense rules. With 2 6 rafters that s a tall order and jordan adds a couple of major caveats. As for insulation thickness it depends on how much you can afford. Recommended roof insulation r value is 38 r but ideal is to have 50 r or more.

Rockwool products are available with a bitumen or mineral coated fiberglass face to be used in a number of roofing solutions. Since your attic is insulated i would advise at least 2 of polyiso insulation in the roof for good measure. Underneath the basics flat roofs are usually constructed with a ceiling nailed to joists which support a deck usually wood in residential construction a vapor barrier insulation and a roof board.