Residential Flat Roof Insulation

With 2 6 rafters that s a tall order and jordan adds a couple of major caveats.

Residential flat roof insulation.

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. Products are also inorganic non combustible and mold resistant. 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. The typical u value of an existing uninsulated flat roof is 1 5w m2k. 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. 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.

Thermafiber residential mineral wool blankets are ideal for insulating walls floor ceilings and attic spaces in homes. Different types of roofing insulation exist including blanket insulation blown insulation and rigid 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. 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.

Since your attic is insulated i would advise at least 2 of polyiso insulation in the roof for good measure. To achieve this add 100 to 160mm of insulation above the structural deck dependant upon insulant conductivity. These products provide a high r value inch excellent sound attenuation characteristics and outstanding fire performance. That accounts for its materials membrane insulation and decking as well as snow and rainfall and even for equipment like an air conditioner.

With a flat roof however this becomes a major concern. Rockwool products are available with a bitumen or mineral coated fiberglass face to be used in a number of roofing solutions. The roof is only four years old so removing it is not an option he says ruling out a layer of exterior rigid foam.