Recommended R Value For Attic Insulation Canada

Your attic should have a certain amount of insulation in it and the recommended level of insulation for your attic is dependent on where you live.

Recommended r value for attic insulation canada.

As a benchmark one inch of solid wood has an r value of 1. In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and an inch of blown cellulose in an attic has an r value of 3 2 3 7. R value measures how well certain building insulation materials can resist heat. See the department of energy s doe ranges for recommended levels of insulation below.

Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system. The amount of insulation recommended for your home will vary depending on a number of factors. After installing insulation in the existing cavities nail or screw strapping 2 x 2 or 2 x 3 on edge perpendicular to the rafters and studs. In such cases where r value is assigned this may decrease the r value requirement for batt insulation.

Inspecting your attic 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. Insulation level are specified by r value.

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. If your attic is not too cramped consider adding strapping onto the rafter bottoms and wall studs to allow for more insulation up to the recommended minimum level for attic insulation if possible. The higher the r value the better the thermal performance of the insulation. R value is a measure of insulation s ability to resist heat traveling through it.

First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation. Know exactly how much you need with our project calculators. The table below shows what levels of insulation are cost effective for different climates and. The higher the r value the greater the insulation performance.

Where you live different climates require different insulation r values. You will need a higher r value of insulation if you live in the north than if you live closer to the us border.