Flat Roof Insulation Thickness

Flat roof insulation thickness the chosen insulation laid on top of this should be able to take the weight of anything put above it on the roof without compression or protected from compression by further sheeting.

Flat roof insulation thickness.

Better to have 3 or more. U value of a flat roof to comply with part l of the building regulations 2010 all roofs to rooms except those in unheated buildings should be thermally insulated to a maximum u value of of 0 18 w m k. Achieving a u value of 0 20w m meaning your roof will be better insulated than your walls will need 120mm thickness of rigid foam or 200mm of mineral wool or natural insulation. The typical u value of an existing uninsulated flat roof is 1 5w m2k.

As for insulation thickness it depends on how much you can afford. However if we do not include removal of old roofing you are looking at about 7 50 to 9 00 per foot of roofing plus about 2 50 to 3 00 per foot of 5 thick insulation say about 10 12 per square foot. Since your attic is insulated i would advise at least 2 of polyiso insulation in the roof for good measure. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.

Find your zone on the map and then use the chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces. Rockwool products are available with a bitumen or mineral coated fiberglass face to be used in a number of roofing solutions. 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. 120mm of kingspan tr26 or similar will make the.

It should be of the maximum available thickness. A lower u value indicates better insulation properties hence u value requirements usually specify a maximum value.