Insulating your roof can be a daunting task. Where do you begin? Which insulation should you choose? Is it safe to install yourself? Don’t worry, we’ll answer each of these questions—and a few more for good measure—right here in this article. Treat this as your one-stop-shop for roof insulation. Let’s get started!

Why is roof insulation important?

The answer to this is very simple, and you likely already know it. Heat rises! Without insulation in your roof, about 30 – 35% of the hard-earned heat from your heat pump or fireplace can easily escape. Roughly 12 – 14% escapes through an uninsulated floor, so if you’re considering insulating just one area of your home, the roof is best. Keeping the heat in means you’ll save money on your power bill, and you’ll only need to wear one layer of socks.

Which insulation is best for your roof?

The GreenStuf range has two insulation products designed for residential roofs, Skillion Roof Blanket and Roll Form. If you have an accessible attic space, then Roll Form is the best choice. However, if you have a skillion roof, you should look to install Skillion Roof Blanket.

Heat always flows from the source to surrounding cooler areas; insulation is designed to slow this heat transfer. The relative efficiency with which it does this is called the R-Value, with ‘R’ representing the insulation’s resistance to heat flow at a given thickness. The higher the R-Value, the more effective the insulation. R-Value is achieved through a combination of density and loft. Some insulation styles—like Roll Form—rely more on loft to meet the required R-Value, whereas thinner products—like Skillion Roof Blanket—rely more on density. If you have an attic space, a loftier insulation is perfect. However, for tight spaces like skillion roofs (where the ceiling slopes with the roof), a denser insulation product is required to achieve the same R-Value.

Installing insulation in your roof

You can install GreenStuf insulation yourself. Made from 100% polyester fibre, it is safe to touch and easy to handle—even in tight spaces. If you have an attic, installing insulation is simple. Every GreenStuf product comes with easy-to-follow install instructions, and DIY install videos are available online with a quick Google search.

Skillion roofs need a bit of planning. As the space between the roof and the ceiling isn’t accessible once the roof is finished, Skillion Roof Blanket needs to be installed during the construction of the roof. This can be done in both new builds and renovations to existing homes. It is important to consider the quality of insulation you are installing in a skillion roof, as once it is installed, it will be very tricky to replace. Unlike other common insulation products, GreenStuf doesn’t slump over time, ensuring your home will stay warm and dry for years to come.

"Without insulation in your roof, about 30 – 35% of the hard-earned heat from your heat pump or fireplace can easily escape."

Handy tips

Check with an industry professional that the insulation you have selected is safe to install over downlights.

Professionals recommend exceeding building code requirements for R-Values. In the case of insulation, more is more!

Avoid ‘thermal bridging’ (heat loss through ceiling joists) by double layering Roll Form insulation in your ceiling. Install the first layer between the ceiling joists, and the second layer over the top, perpendicular to the first, to cover the joists.