Roof Insulation Board Thickness

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.

Roof insulation board thickness.

This product provides two layers of insulation installed in one application which reduces labor and material costs. A flat roof should preferably be insulated from above. Rigid roof insulation board. Hitting amazing levels of 0 13w m will need 300mm of mineral wool or 180mm of rigid foam.

Firestone isogard hd composite cover board is ideal for both new construction and reroof applications with available thicknesses from 1 5 to 4 two board sizes and three coated glass facers that provide mold resistance. Not only do we withstand hail damage but our roof boards maintain their bond to the roof membrane lowering the likelihood of a catastrophic roof failure. 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. Coated fiberglass facer ideal for fully adhered systems provides a broader compatibility and higher performance with roofing adhesives.

It comes in standard size 4 8 sheets and smaller sizes in many different thicknesses from 1 4 inch to 2 inches. Some types of thicker foam board insulation are available but they may need to be special ordered. This is best done when the roof covering needs replacing anyway. Foam board insulation is easy to use and is a great diy way to add some insulation.

Fm class 1 for fire barrier requirements and ul class a unlimited slope with excellent surface burning characteristics. Composed of a closed cell polyisocyanurate foam core bonded in the foaming process to 1 2 thick duraboard an expanded perlite mineral aggregate board on one side and a fiber glass reinforced facer on the other. Meets the requirements of astm c 1177. Excellent lttr value compared to any other fm class 1 rated products of equivalent thickness.

So you need to know an insulation product s thickness as well as its r value in order to compare it to another product. 5 8 thickness meets the requirements of type x per astm c 1177. The same insulation will hold more heat the thicker it is installed. Fm approved subject to the conditions of approval as a roof insulation when installed as shown in the current edition of the factory mutual research approvals guide.