blow-in attic insulation toronto

How Much Attic Insulation is Recommended in Ontario

The effectiveness of insulation is measured in relation to its thermal resistance which is a way of saying how much conductive heat flow the product stops from going through it. This measurement is described as R-Value. Generally speaking, a higher R-value means better insulating properties. The recommended R-value for attic insulation in Ontario is between R-50 and R-60.

R-Values of Common Types of Insulation

The two distinct types of attic insulation are loose-fill material (also commonly known as blown in insulation) and batting. The R-Value of the insulation for every inch of thickness depends on the type of insulation. As a general guide from the Department of Energy, the R-Values for the most common types of insulation per inch are;

Loose-fill Cellulose3.1 – 3.8
Loose-fill Fiberglass2.2 – 2.9
Loose-fill Stone Wool2.2 – 3.3
Fiberglass Batting2.9 – 3.8
Stone Wool Batting3.3 – 4.2
Polyurethane Foam5.6 – 8.0
Cementiotious Foam2.0 – 3.9


These values are a rough guide as the true R-Value of the insulation depends on more factors than the indicated R-Value as explored in detail below.

Factors Affecting Insulation R-Value

Just because the insulation says its R-60 doesn’t necessarily mean that’s what you are going to get once it is installed. There is a distinction to make between nominal R-Value which is the advertised value on the product packaging and the Effective R-Value which is the actual performance of the product as measured in real life conditions. Factors that influence exactly how the attic insulation performs other than the indicated R-Value include;

Brand Name

Like most other products on the market, the insulation brand name matters. Go for known brands that have a proven track record of good performance and purchase from a reputable dealer. If you have no idea where to begin, consult an expert who can give you enough information to make an informed decision. Additionally, look out for third-party certification such as GreenGuard, EcoLogo, SCS Certified and CCMC especially when buying specialized products such as sustainable or eco-friendly insulation. This independent certification adds credibility which is essential if you are paying higher than normal prices for specialized insulation.


There is a lot more work that goes into installing attic insulation than simply laying the batting or blowing the loose-fill material into place. Most of these considerations require specialized knowledge and experience which is why it is impossible to replicate the effectiveness of professionally installed insulation when attempting to do it yourself. There are also additions such as air barriers, thermal bridges, vapour retarders and much more which help the insulation to work at its most efficient.

Attic Flaws

Closely related to the previous point, attic flaws such as under-insulted vent pipes and ducts, under-ventilated attic, architectural flaws, moisture issues, awkward fixtures and air leaks among others all have to be addressed before installing the insulation. The effectiveness of the insulation can be cut drastically with even one of these flaws regardless of the quality, brand or R-Value you are installing.

Attic Insulation Toronto has decades of experience working around these issues and more to make sure that you are getting the best in energy efficiency, soundproofing and ambient temperature advantages from your new insulation.

Density and Thickness

The actual thickness of the insulation isn’t the only consideration when measure R-Value so thick insulation doesn’t always translate to the most effective. There is also the issue of settling particularly with blown-in insulation where the material shifts and settle over time, reducing its R-Value. This problem is easy to overcome by over-insulating but it is not always obvious how much more insulation you need in this case. There might also be space and architectural constraints to overcome which will largely influence the density and thickness you choose to install.

Hire an Expert to Install Attic Insulation in Ontario

Although the recommended R-value for attic insulation is Ontario is straightforward at between R-50 to R-60, there are too many factors at play to make this a DIY project that you can do properly without the relevant training, certification and experience.

Call Attic Insulation Toronto for professional guidance every step of the way from inspection, choosing the right insulation, insulation and assessing to confirm that the new insulation is performing as expected. The savings you make in lower energy bills alone more than pay for the cost of having your insulation installed professionally. 647-931-6385