Residential Flat Roof Insulation

Can a flat roof be insulated from inside from the ceiling of the area below.

Residential flat roof insulation.

Insulating a roof from inside is technically feasible. Rockwool products are available with a bitumen or mineral coated fiberglass face to be used in a number of roofing solutions. Better to have 3 or more. The target should be to achieve a u value of 0 25w m2k or better.

These products provide a high r value inch excellent sound attenuation characteristics and outstanding fire performance. Recommended roof insulation r value is 38 r but ideal is to have 50 r or more. 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.

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. 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. This system was often used in the past but is not recommended nowadays. 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. 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. It s what s called the cold roof principle. 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. Different types of roofing insulation exist including blanket insulation blown insulation and rigid insulation. As for insulation thickness it depends on how much you can afford. From there the flat roof system you choose will determine the materials you apply.

In fact it may cause damage in the long term.