Unfortunately, you’ll have a hard time finding a straightforward answer to the question posed in the title of this article. As any insulation company will tell you, the reality of insulation is a little more complicated than simply assigning a single value to every situation. However, this is no reason for despair since there are some general guidelines that make choosing the right insulation R-value simpler.
What is R-value?
R-value is a measure of an insulation’s ability to block heat. The higher the value, the better an insulation material will retain heat and prevent it from dissipating. Generally, the thickness of the insulation is tied to the r-value, meaning the thicker the insulation layer, the higher the r-value.
Choosing R-value Based on Region
If you’ve searched this question and gone through the image results, chances are you’ve seen some very colourful maps dividing Canada into east-west strips. These are meant to differentiate between the average temperatures in these locations so that you insulate to stave off the coldest temperatures in your region.
Here’s the thing: R-value is only marginally affected by super cold temperatures. You’ll find that the places that require the most insulation still call for an R-value of 40-60, whether it is in balmy Vancouver or chilly Fort McMurray. Furthermore, the higher R-values aren’t required or anything; they’re just suggestions for greater insulative capacity, which can actually work against you in places where high temperatures are also possible.
Choosing R-value Based on Purpose
It’s common knowledge that heat rises. This simple statement means a lot to insulation companies and so it should mean a lot to you too. After all, the purpose of insulation is always the same, but the application isn’t. For example, the roof of your building will require the most insulation since, you know, heat rises. The walls will require substantially less insulation, on average.
Okay, with that out of the way, we now give the next general rule of insulation and R-value, which is that the roof is where you need that 40-60 range. Otherwise, you can use any insulation in the range of 19-30. And that’s pretty much all you need to know about choosing insulation based on R-value, so we’ll just review things and wrap up this article.
The R-value Rules to Respect
First, R-value doesn’t need to exceed 40 in most circumstances. Where that may be the case is in the coldest parts of Canada, and even then, only for the roof portion. Wall insulation can stay between 19-30 on the scale. As R-value is tied to the thickness of your insulation (and the type, of course), the consideration for thickness in walls should be based on other construction factors and not so much the ideal insulation thickness. Finally, you don’t necessarily have to go and learn new R-value rules for every new region or place you visit in Canada since they don’t really change significantly across the country. For any additional information or clarification, contact an insulation company near you today.