Roof Insulation R Value Canada

R3 r18 r21 total roof r value.

Roof insulation r value canada.

I calculate insulation resistance to heat loss or r percentage improvement always as relative to the original number. Thickness inches r value in i p imperial rsi r value in metric 0 5. For a very good introductory overview article on r value see r values over at the website of. If installed uncompressed in a 152 mm cavity e g some manufactured framing products it will retain its full thermal resistance value of 3 52 m2 k w.

Conditioned per atsm c1289 test method astm c5181 2. One method involves installing rigid board insulation on top of the existing roof see figure 5 25. Foam plastic insulation on the interior of the building envelope must adhere to the requirements of protection of foamed plastics as per 9 10 17 10 of the national building code of canada. The r value of the insulation for every inch of thickness depends on the type of insulation.

R value measures how well certain building insulation materials can resist heat. The percentage increase increase increase original number 100. The higher rsi value of rigid insulation means a smaller increase in the roof thickness although several layers of insulation may be needed to meet the desired rsi level. R value of various materials.

R value chart for enerfoil tm rigid foam faced insulation. 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. The recommended r value for attic insulation in ontario is between r 50 and r 60. When determining how much insulation you need don t guesstimate calculate.

You should of course see the manufacturer provided technical data sheet for the r value of specific products. An rsi 3 52 r20 per 152 mm batt compressed into a 140 mm cavity has a thermal resistance value of 3 34 r19. The higher the r value the greater the insulation performance. R values of common types of insulation.

Depending on where you live and the part of your home you re insulating walls crawlspace attic etc you ll need a different r value. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. The two distinct types of attic insulation are loose fill material also commonly known as blown in insulation and batting. In such cases where r value is assigned this may decrease the r value requirement for batt insulation.