Insulating yourself against energy costs
Tuesday, October 21st 2008 10:23:59am
Now is the time to upgrade your home insulation
With a Canadian winter right around the corner, it is time again to make sure you're ready. Ensuring you have the proper draft proofing and the right amount of insulation in your home remains one of the best things you can do for the environment and your wallet.
Inadequate insulation is one of the main reasons why the average home can lose up to 50 percent of its energy. By adding insulation, you lower the amount of energy needed to heat your home, resulting in fewer associated greenhouse gas emissions and a lower monthly heating bill.
To achieve maximum thermal efficiency and comfort, it is important to insulate any space where energy could be lost.
1. Attics and ceilings
The attic is one of the largest sources of potential heat loss and is often neglected when it comes to insulation, even in homes that are less than ten years old.
Regardless of whether you use your attic as a living space, insulation is essential. Warm air rises, and if an attic is lacking the proper type and amount of insulation, heat will escape through the roof. Consequently, you will want to add between R-8 and R-30 insulation to the existing insulation (R-value is a measure of thermal resistance).
If your attic is unfinished, you, or a contractor, can install either fiber glass, mineral wool or blown-in insulation in the floor joists. If the attic is finished, fiber glass and mineral wool blown-in insulations are the best options.
2. Don't forget the walls
The walls between living spaces and unheated garages, storage rooms, dormer walls, and above the ceilings of adjacent lower sections of split-level homes are often overlooked. Insulating these areas, when possible, will save heat and help minimize noise.
If you are able to access the walls when renovating, be sure to upgrade insulation and vapour barriers. For 2 x 4 construction, use the highest R-value, R-12 to R-14. For 2 x 6 construction, use R-19 to R-22.
It's unwise to compress a batt (a rectangular piece of insulation) for 2 x 6 construction to make it fit into a 2 x 4 construction as compression dramatically reduces the R-value. R -19 compressed into a 2 x 4 construction, for example, would result in an R-value of less than 12. The insulation should fit, but shouldn't be compressed.
R-20 (or higher) insulation is usually cut into small pieces to fit snugly between the floor joists, sills and band joists. Full batt insulation of R-25 can be used on the ceilings above unheated basements, crawlspaces, garages and porches.
4. Basements and crawlspaces
In an otherwise well-insulated house, as much as 25% of the total home heat loss can occur through uninsulated foundation walls and floors.
If the basement is an unheated space and isn't used as a living area, insulate between the floor joists for the room above, instead of around the exterior or perimeter walls. This keeps heated air in the living areas where it belongs, and out of the basement. R-25 insulation is recommended.
Conversely, if the basement is going to be heated and used, you need to insulate the basement walls. The simplest method is to build 2 x 4 frames against the concrete foundation walls and use R-12 to R-22 fiber glass or mineral wool insulation beneath the drywall. Vapor retarders should face heated areas and be covered as soon as possible.
For crawlspaces, fiber glass or mineral wool insulation is the most typical products used to insulate these areas. R-20 to R-22 insulation can be cut into small pieces to fit snugly between the floor joists, against sills and between band joists. If a crawlspace wall is vented, you should insulate the floors above with R-25 and not the crawlspace walls.
While adding insulation can save a lot of energy, it is benefited by good construction methods; including a moisture resistant exterior barrier, a vapour barrier on the heated side, proper ventilation and energy efficient windows will make for a healthy, comfortable and cost effective home.
For more on the life cycle and environmental attributes of fiber glass and rock and slag wool insulations, visit www.naima.org/pages/benefits/environ/environ.html
Steve Koch may be reached at (613) 232-8093.
Stephen Koch is the Executive Director of the North American Insulation Manufacturers Association (NAIMA) Canada, which promotes energy efficiency and environmental preservation through the use of fibre glass, rock wool, and slag wool insulation, and encourages the safe production and use of these materials.