Roof Insulation Board Thickness

Exceptional dimensional stability and rated for extreme hail rockwool stone wool insulation roof boards have meet both the fm severe hail and the ul 2218a standard for impact resistance.

Roof insulation board thickness.

Rigid roof insulation board. It comes in standard size 4 8 sheets and smaller sizes in many different thicknesses from 1 4 inch to 2 inches. 5 8 thickness meets the requirements of type x per astm c 1177. Fm class 1 for fire barrier requirements and ul class a unlimited slope with excellent surface burning characteristics.

So you need to know an insulation product s thickness as well as its r value in order to compare it to another product. Hitting amazing levels of 0 13w m will need 300mm of mineral wool or 180mm of rigid foam. Foam board insulation is easy to use and is a great diy way to add some insulation. Excellent lttr value compared to any other fm class 1 rated products of equivalent thickness.

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. Eight inches of poor quality insulation may have a higher and better r value than one inch of top quality insulation. This is best done when the roof covering needs replacing anyway. Some types of thicker foam board insulation are available but they may need to be special ordered.

A flat roof should preferably be insulated from above. 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. Meets the requirements of astm c 1177. 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.

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 same insulation will hold more heat the thicker it is installed. This product provides two layers of insulation installed in one application which reduces labor and material costs. 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.