Roof Insulation R Value Canada

I calculate insulation resistance to heat loss or r percentage improvement always as relative to the original number.

Roof insulation r value canada.

R value chart for enerfoil tm rigid foam faced insulation. In such cases where r value is assigned this may decrease the r value requirement for batt insulation. R values of common types of insulation. One method involves installing rigid board insulation on top of the existing roof see figure 5 25.

For a very good introductory overview article on r value see r values over at the website of. 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. The higher the r value the greater the insulation performance. 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.

The increase r21 r3 exactly 18 the value by which you are increasing the r value. The percentage increase increase increase original number 100. You should of course see the manufacturer provided technical data sheet for the r value of specific products. R3 r18 r21 total roof r value.

Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. The r value of the insulation for every inch of thickness depends on the type of insulation. When determining how much insulation you need don t guesstimate calculate. 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.

R value measures how well certain building insulation materials can resist heat. The recommended r value for attic insulation in ontario is between r 50 and r 60. 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. An rsi 3 52 r20 per 152 mm batt compressed into a 140 mm cavity has a thermal resistance value of 3 34 r19.

Conditioned per atsm c1289 test method astm c5181 2. 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. See the department of energy s doe ranges for recommended levels of insulation below. Thickness inches r value in i p imperial rsi r value in metric 0 5.