Residential Flat Roof Insulation

The typical u value of an existing uninsulated flat roof is 1 5w m2k.

Residential flat roof insulation.

The target should be to achieve a u value of 0 25w m2k or better. Different types of roofing insulation exist including blanket insulation blown insulation and rigid insulation. With a flat roof however this becomes a major concern. 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.

Since your attic is insulated i would advise at least 2 of polyiso insulation in the roof for good measure. Rockwool products are available with a bitumen or mineral coated fiberglass face to be used in a number of roofing solutions. From there the flat roof system you choose will determine the materials you apply. The roof is only four years old so removing it is not an option he says ruling out a layer of exterior rigid foam.

These products provide a high r value inch excellent sound attenuation characteristics and outstanding fire performance. 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. 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.

That accounts for its materials membrane insulation and decking as well as snow and rainfall and even for equipment like an air conditioner. 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. 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. Better to have 3 or more.

With 2 6 rafters that s a tall order and jordan adds a couple of major caveats. In climate zone 5 the prescriptive table of the international residential code requires at least r 49 of ceiling insulation. Thermafiber residential mineral wool blankets are ideal for insulating walls floor ceilings and attic spaces in homes.