How to Properly Insulate Your Roof

The roof over your head is your primary line of defense against the elements, including the blistering heat of summer and frigid cold temperatures of winter. However, your roof alone can’t do much to fight back against heat transfer, which is a serious problem during both summer and winter. During winter, the warmth you need in your home will seep out through your roof, and leak into your home during blistering summer days. Both of these phenomena lead to lower efficiency, higher energy bills, and believe it or not, a shorter lifespan for your roof in general.

Fortunately, you don’t have to live with this problem: properly insulating your roof and your attic space can both reduce energy loss and preserve your roof to help it last for many years to come. That is, if you do it properly. Sadly, many people don’t exactly know what they’re doing when it comes to insulating their roof and attic space, and that leads to costly air gaps and ineffective sealing that does little to stop heat loss and may even damage their home. On this blog, we’ll discuss how to avoid these mistakes and properly insulate your roof.

Measure Correctly

When you’re using blown or rolled fiberglass blankets as insulation, you’ll need an accurate estimate as to how much space you’re going to have to insulate. Don’t worry about being precise: simply measuring the length and width of your attic is enough to get a good estimate for how much material you’ll need to buy. It’s always a good idea to buy a bit more than you might think you need to.

Install Sheeting

The first thing you’ll need to put down is plastic sheeting over the floor of your attic. Between the rafters in your attic, place enough plastic sheeting to coat the entire floor and climb up the walls several inches. Make sure that you seal all gaps, however do not block attic vents, as they’re extremely important to your roof’s condition and preventing mold and mildew growth in your attic. It’s perfectly ok to have multiple pieces of plastic: just make sure you use duct tape to secure it and seal any air gaps.

Blown Insulation Installation

Blown insulation is installed using a blower, and each brand may have different installation instructions, so make sure you read the included instructions carefully. Blow a layer between your attic joists, and then another thin layer over the top once that one done. If you have floorboards in your attic, it’s a good idea to blow a full, thick layer beneath the boards, replace them, and then blow another thin layer over the top for maximum effectiveness.

Rolled Insulation

Rolled insulation requires precision: even a one-inch gap can lead to a 20 percent loss in heating and cooling efficiency. Make sure your insulation has no cracks or gaps and sits flush with your roof floor joists. You should also consider sticking rolled insulation between your roof rafters for maximum effectiveness. Likewise, feed some of this insulation beneath any exposed wires or pipe, and then place plastic sheeting over the top of it to seal it.

Spray Foam

Spray foam insulation is rapidly becoming an extremely popular form of insulation because it’s both quick to install and remarkably effective. However, it does require special tools (usually an air powered paint gun, and you have to mix the chemicals precisely in order to get the optimal results. There are DIY kits for spray foam, but we don’t usually recommend them because even homeowners who have considerable handiwork skills can make a mistake. If you’re considering installing this type of foam to insulate your attic, it’s usually worth the extra cost to hire a professional.