INSULATE ATTIC PROPERLY TO PREVENT HOME HEAT LOSS
Icicles, patches of melted snow on roof are signs that must not be ignored
Many homeowners send me notes concerned about losing heat in their homes.
This is especially true during the winter months, when their furnaces are working overtime. They still aren’t seeing their thermostats rising to the level expected, and even worse, they’re turning the heat way up, seeing that extra cost on their bills — but not getting the warmth they need.
Let’s address this problem from the very top.
THE ATTIC
Your attic, if not properly ventilated and insulated, can be the culprit of a home that will cost you, either through your furnace running overtime, or through damage caused by a home that can’t adapt to the winter season.
Your attic is a cold zone — that means it should be the same temperature as the outside air. By letting heat escape freely from your home into the attic, and having cool air from the outside meet in the middle, you may have a problem.
You’ll be able to tell if your attic is losing heat in the winter. Take a look at your roof after a snowfall: Are you seeing icicles and patches of melted snow? That’s a sign of heat loss.
There are companies that can collect heat loss data from entire neighbourhoods by flying overhead with thermographic imaging technology. If your city is covered, this is a great way to easily check how energy efficient your home is — and find ways to mitigate any heat loss.
R-VALUE
R-value refers to the capacity an insulating material has to resist heat flow. The higher the R-value, the better the material can insulate.
Remember, just because one style of insulation is thicker than another, doesn’t mean that will be more effective for keeping your house warm.
TYPES OF INSULATION
There are a lot of options for insulating your attic, each with their own pros and cons.
When I insulate an attic, I aim for an R-value of at least 60. That will help keep my house nice and warm in the winter, but cool during the summer.
BATT INSULATION
Typically made of Fiberglas or mineral wool, batt insulation are strips of material that fit between the ceiling joists to provide insulating power. Batt insulation should be loose-fitting — within the material is a lot of air that provides extra R-value. By compressing batt insulation, you will actually be losing R-value.
FOAM BOARD INSULATION
Rigid panels of insulation are most commonly made from polystyrene or polyurethane. Foam board can be used on an attic hatch, but wouldn’t be used to insulate the entire space, generally being reserved for exterior wall sheathing or basement walls.
BLOWN-IN INSULATION
The most common type of insulation you’ll find in attics. Small chunks of insulating material (typically Fiberglas and cellulose) is blown into the attic space in smaller chunks. Like batt insulation, blown-in insulation should be fluffy. It will lose R-value when it’s been compressed. Sustainability and building for the future is something that I believe in, and the cellulose used in blown-in insulation is an environmentally friendly product.
Adding blown-in insulation is a job that you will need to leave to the professionals.
SPRAY FOAM INSULATION
A polyurethane foam is sprayed in the attic which will fill cracks and gaps, forming a barrier. There are two types of spray foam insulation: closed cell and open cell. Open-cell foam is permeable to moisture, but impermeable to air, while closed-cell foam stops air and moisture. Closed-cell spray foam provides the highest R-value, offering a value of up to seven per inch.
Installing a spray foam isn’t a do-it-yourself job. Amateurs tend to pile the insulation too high, blocking out the soffit vents which cuts off all ventilation in the attic. If you aren’t careful, this can lead to ice dams which can cause major damage to a roof.
ICE DAMMING
Ice damming is more likely to be an attic issue than one with your eavestroughs. Too little insulation at the perimeter of the attic can result in heat loss coming in contact with cold air, creating condensation and freezing. One way to solve this issue is by using a closed-cell spray foam just around the edges of the attic. Watch Mike Holmes in his series, Holmes Makes It Right, on HGTV. For more information, visit makeitright.ca.