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.
Recommended r value for attic insulation canada.
Recommended home insulation r values.
Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system.
First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation.
The higher the r value the greater the insulation performance.
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.
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.
See the department of energy s doe ranges for recommended levels of insulation below.
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.
Recommended r value for attic insulation canada the recommended r value for insulation of attics in canada depends on the area as it is a value that changes a lot from area to area.
When determining how much insulation you need don t guesstimate calculate.
R value is a measure of insulation s ability to resist heat traveling through it.
You will need a higher r value of insulation if you live in the north than if you live closer to the us border.
The province the city and the area greatly influence the difference in r value for the insulation of an attic.
The amount of insulation recommended for your home will vary depending on a number of factors.
The higher the r value the better the thermal performance of the insulation.
The table below shows what levels of insulation are cost effective for different climates and.
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.
As a benchmark one inch of solid wood has an r value of 1.
In such cases where r value is assigned this may decrease the r value requirement for batt insulation.
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.
Inspecting your attic insulation.
Know exactly how much you need with our project calculators.