Roof Insulation R Value Canada

An rsi 3 52 r20 per 152 mm batt compressed into a 140 mm cavity has a thermal resistance value of 3 34 r19.

Roof insulation r value canada.

Know exactly how much you need with our project calculators. R value chart for enerfoil tm rigid foam faced 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. R value of various materials.

R3 r18 r21 total roof r value. The two distinct types of attic insulation are loose fill material also commonly known as blown in insulation and batting. For a very good introductory overview article on r value see r values over at the website of. The recommended r value for attic insulation in ontario is between r 50 and r 60.

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 increase r21 r3 exactly 18 the value by which you are increasing the r value. In such cases where r value is assigned this may decrease the r value requirement for batt insulation. You should of course see the manufacturer provided technical data sheet for the r value of specific products.

Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. 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 measures how well certain building insulation materials can resist heat. R values of common types of insulation.

The percentage increase increase increase original number 100. When determining how much insulation you need don t guesstimate calculate. 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. Thickness inches r value in i p imperial rsi r value in metric 0 5.

Conditioned per atsm c1289 test method astm c5181 2. I calculate insulation resistance to heat loss or r percentage improvement always as relative to the original number. One method involves installing rigid board insulation on top of the existing roof see figure 5 25. The higher the r value the greater the insulation performance.