Roxul For Roof Rafters

Rigid foam also can be installed above the roof sheathing in tandem with air permeable insulation between the rafters.

Roxul for roof rafters.

Installing stone wool insulation in the attic space of a low slope roof can provide increased thermal efficiency. Rigid foam on roof sheathing with air permeable insulation between the rafters. In this case the rigid foam can be thinner than when it s used alone. Other relevant factors include the type of wood being used for the rafters the size of the rafters and the load that the rafters need to support.

When determining how much insulation you need don t guesstimate calculate. 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. 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. The spacing between rafters in a given building is part of the engineering calculations that determine the required structure of the roof.

Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run. Rafters are commonly spaced about 24 inches 61 cm apart. Code specifies the minimum r value of the rigid foam layer. The number of rafters needed will be determined by the length of your roof.

R value measures how well certain building insulation materials can resist heat. Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch.