Residential Flat Roof Insulation

From there the flat roof system you choose will determine the materials you apply.

Residential flat roof insulation.

Recommended roof insulation r value is 38 r but ideal is to have 50 r or more. The roof is only four years old so removing it is not an option he says ruling out a layer of exterior rigid foam. Thermafiber residential mineral wool blankets are ideal for insulating walls floor ceilings and attic spaces in homes. That accounts for its materials membrane insulation and decking as well as snow and rainfall and even for equipment like an air conditioner.

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. Rockwool products are available with a bitumen or mineral coated fiberglass face to be used in a number of roofing solutions. The typical u value of an existing uninsulated flat roof is 1 5w m2k. 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.

To achieve this add 100 to 160mm of insulation above the structural deck dependant upon insulant conductivity. Different types of roofing insulation exist including blanket insulation blown insulation and rigid insulation. Since your attic is insulated i would advise at least 2 of polyiso insulation in the roof for good measure. The target should be to achieve a u value of 0 25w m2k or better.

In climate zone 5 the prescriptive table of the international residential code requires at least r 49 of ceiling insulation. Better to have 3 or more. 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. 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.

With 2 6 rafters that s a tall order and jordan adds a couple of major caveats. Products are also inorganic non combustible and mold resistant. As for insulation thickness it depends on how much you can afford.