Recommended Flat Roof Insulation Thickness

Since your attic is insulated i would advise at least 2 of polyiso insulation in the roof for good measure.

Recommended flat roof insulation thickness. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. A flat roof should preferably be insulated from above. Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces. R value is a measure of insulation s ability to resist heat traveling through it.

With solutions ranging from our optim r vacuum insulation panels to our therma range of pir insulation we can provide the best solution for flat roof insulation for roofs with mechanically fixed bonded or torch applied waterproofing systems. The higher the r value the better the thermal performance of the insulation. For every type and material of insulation check the r value per inch of thickness that the manufacturer has listed. Better to have 3 or more.

It should be of the maximum available thickness. First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of 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. Whether the flat roof being installed will be walked on or not flat roof insulation board typically has a hard faced surface and good compressive strength both for extra stability and.

Recommended home insulation r values. Flat roof insulation thickness. In general how the insulation s method of installation can give you an idea of how it compares to other types of insulation. Using insulation board in a flat roofing insulation build up is a widely accepted industry standard as it s one of the best weight bearing insulation types.

Recommended roof insulation r value is 38 r but ideal is to have 50 r or more. See the department of energy s doe ranges for recommended levels of insulation below. Your attic should have a certain amount of insulation in it and the recommended level of insulation for your attic is dependent on where you live. The typical u value of an existing uninsulated flat roof is 1 5w m2k.

Insulation level are specified by r value. As for insulation thickness it depends on how much you can afford. Our range of high and optimum performance flat roof insulation products are suitable for use in a range of flat roofs. A layer of rigid insulation board can be added either on top of the roof s weatherproof layer or directly on top of the timber roof surface with a new weatherproof layer on top of the insulation.

The table below shows what levels of insulation are cost effective for different climates and. 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.