Whether you’re insulating a finished area, or embarking on a new build or renovation, preparing for the insulation of your attic is a crucial part of your project. The right insulation materials and techniques ensure your house is warm, energy-efficient, and can even withstand weather damage to your roof. Follow these tips to learn the pros and cons of different attic insulation material, as well as how much you’ll need, and other key considerations to make sure your insulation job stands the test of time.
The Science Behind Insulation
First, let’s get back to basics: why do we insulate attics? The process ensures that heat rising through your house to the roof doesn’t do damage to the roof and rest of the house as it condenses, or combines with melting snow on the exterior. That hot, condensed air can lead to problems with rot and mold. When combined with melting snow on the outside, this can lead to frost on the interior of your roof, or ice dams on the exterior. Ice dams can damage not only your roof, but your gutters, paint job, structure of your house, and your insulation. You can learn more about techniques and materials to tackle the common problem of ice dams in this blog article.
Combat the Draft
So, when it comes to prepping the space for insulation, it’s key that you get the attic ready to withstand air flow and outside weather, and to set up the insulation to succeed at its job for years to come. You or your contractor’s first goal is to draft-proof, focusing on any areas or potential draft spots: the areas around electrical boxes, holes for pipes and wires, chimneys, attic hatches, and kneewalls.
If you’re prepping for insulation yourself, ensure the materials you’re using for draft-proofing are the correct ones, meeting any fire safety regulations. For instance, lights in the ceiling below the attic will be labelled as to whether they’re IC (insulation contact)-ready, and chimney draft-proofing must be done with a fire-proof material such as sheet metal.
Finally, your roof needs to be draft-proofed with moore vents, also known as rafter vents, such as Owens Corning’s Raft-R-Mate. These are crucial for allowing air to flow up through the rafters into the attic following the installation of your insulation.
Choosing the Type of Insulation
Batt (also known as blanket) or blown-in (also known as loosefill) insulation have different strengths and weaknesses. For a new house build where your walls and ceilings are still exposed, batt insulation may make more sense: accessing smaller and hard-to-reach spaces to install each batt is potentially easier than if you’re dealing with a retrofit. If you’re doing an insulation job yourself, batt insulation is also easier to procure and install, as long as you’re wearing the right personal protective equipment.
If your walls and ceilings aren’t exposed, blow-in insulation using blown fiberglass or cellulose is a faster and more precise option. Though it requires special machinery and professional installation, it allows you to be more targeted, with the potential to layer the insulation until you achieve the thickness you’re going for. In this video, Owens Corning breaks down the benefits of using loosefill in a retrofit, demonstrating how loosefill fibreglass, such as the brand’s ProPink loosefill insulation, can be more precisely and thoroughly applied to every part of the attic that needs it.
There are also cases where it makes sense to use both batt and blown-in: batts for the more open areas, and blow-in for the smaller, hard-to-reach areas. Keep in mind that both types have long lifespans, typically 15 to 20 years for batt insulation, and sometimes as long as 20 to 30 years for blown-in cellulose insulation. The needs for replacement are similar: water damage, mold or fungal growth, or significant or prolonged weather damage to your house.
How Much Do You Need?
Knowing how much you’ll need first means figuring out the R-value for where you live. The insulation’s R-value simply tells you the strength or capacity of the material. Milder climates require lower R-values around R-30, while colder climates can require R-values as high as R-60. Consult with an expert on what’s needed for your attic, and consider that older houses will typically require more insulation. Knowing the dimensions of your attic, plus the type and thickness of any existing insulation, you can use an online calculator or an expert’s knowledge to get an estimate of how much insulation you’ll need.
Once you’re ready with your specs, explore Owens Corning’s attic insulation products for insulation that can not only protect your house and regulate its temperature, but provide you energy savings and even noise control.