Rubber Roof Membrane R Value

Both types have an r value ranging from 4 r to 6 r per 1 inch of insulation thickness.

Rubber roof membrane r value. For a very good introductory overview article on r value see r values over at the website of. Expanded polystyrene eps with the highest r value per dollar eps is used for roof wall and floor insulation. Xps is semipermeable with a perm rating of 1. For white and black membranes the table outlines the necessary adjustments in r values to maintain a roof assembly s energy performance.

Gaf tpo roofing membranes include. Eps can be used for ground contact and does not retain water over time. After it ages a few months the r value will reduce to somewhere. Mechanically attached installation uses heavy duty screws and barbed plates to hold the membrane down tightly and is not affected by possible iso de lamination.

The amount shown is an average amount used for roof system r value calculations. For a 1 inch board equivalent of 6 r value. For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1 93721. The membrane is attached using 12 o c.

You should of course see the manufacturer provided technical data sheet for the r value of specific products. We recommend having at least 20 r value worth of material for optimal energy efficiency. Please note that the r values for roof membranes shingles tiles air films and roof deck materials might or might not be permitted by your local code to be included when total roof assembly r. The average cost of extruded polystyrene insulation is 0 42 sq ft.

To convert rsi to r value multiply the rsi by 5 67826. For example while optimum performance using a black membrane the assembly must utilize insulation with an r value of 29. While expensive the best insulation is polyiso rigid foam. The average r value is r 5.

R value of various materials. Extruded expanded polystyrene insulation is commonly used in inverted roof membrane assemblies irma. Quite the contrary in colder regions ashrae zones 4 through 8. You can expect to pay about 55 100 sq ft.

It is top quality and the most cost effective product for your flat roof. Pattern with perimeter sheets attached 6 o c. For a 1 in thick panel.