I started 2007 with the theme "Go green" so it seems fitting to re-emphasize that motto in one of my final columns of the year. Besides, I've had heat on the brain ever since winter arrived. I consider the icicles hanging off my nose revenge for the wonderful summer we enjoyed. It therefore seemed like a sign when a news release on insulating your home arrived in my mailbox.
It came from NAIMA Canada, a sister organization to the North American Insulation Manufacturers Association, a global group of building-product manufacturers, including makers of fibreglass, rock wool, and slag wool insulation. In its release, NAIMA Canada offers some tips on keeping warm and snug this winter while reducing your environmental footprint and energy bills to boot.
Because warm air rises, ensure that heat isn't escaping through your roof because of a poorly insulated attic. This applies even to newer homes. Steve Koch, executive director of NAIMA Canada, recommends adding insulation with a value between R-8 and R-30, using either a product that is blown in (done by a contractor) or one that is installed in batt, or sheet, form. (R-value is a measure of thermal resistance.)
He goes on to advise that, "For blown-in applications, there are three products that can be used (though not together): fibreglass, rock/slag wool or cellulose. Each is made from a different base material but all three are referred to as 'loose fill.' The R-value calculations are based on the depth of the product once it's been blown in. Contractors will typically staple a product information card to a truss in the attic where the product is used to identify what it is, the date of application, the volume or number of bags used, and the stated R-value per inch. This is how about 90 per cent of homes are insulated."
Unlike applying loose fill, installing batt insulation in attics can be done by do-it-yourselfers, and the product, made of fibreglass or rock/slag wool, is readily available at building material stores. Besides being easy for a homeowner to install, this form of insulation offers another advantage. If you tuck it in between the floor joists of the attic and then add a second layer across the top and perpendicular to the joists, you can not only double the R-value, you can eliminate what is called "thermal bridging." This is when the joists get cold and you can actually see their faint outline in the drywall ceiling of the room below.
Ensure that walls between living areas and unheated spaces such as a garage are insulated. If you're opening those walls during renovations, NAIMA Canada recommends you take advantage of the opportunity to upgrade the insulation and vapour barriers. It suggests that for two-by-four construction, you install insulation with a value of R-12 to R14, and for two-by-six construction, use R-19 to R-22.
But don't assume that stuffing great wads of insulation into the spaces between studs or joists will give you better results. Compressing insulation actually reduces its R-value, so keep it snug but not packed in.
To insulate floors, cut sheets of R-20 or higher-value insulation into pieces that will fit snugly between floor joists, sills and band joists. Use full batt insulation of R-25 in the ceilings of unheated basements, crawlspaces, garages and porches.
NAIMA Canada says that, "In an otherwise well-insulated house, as much as 25 per cent of the total home heat loss can occur through uninsulated foundation walls and floors." Therefore, if your basement isn't actual living space, add R-25 insulation between the floor joists of the rooms above it. This will ensure that heated air stays in those rooms.
If you have an unfinished basement that you want to convert to living space, the organization offers this simple approach to insulating the walls: "Build two-by-four frames near the concrete foundation walls and use R-12 to R-22 fibreglass or mineral wool insulation beneath the drywall. Ensure that the insulation does not rest against the concrete wall. Vapour barriers should face heated areas and be covered as soon as possible."
If, however, your basement is already finished, you won't want to tear out the drywall to add insulation. In this case, NAIMA Canada recommends you find "other areas of your home that are easier to access" and add insulation there.
For example, in crawlspaces, use R-20 to R-22 fibreglass or mineral wool insulation "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. When insulating the walls, make sure to verify that [they] are dry and do not leak ground moisture."
See the organization's website, www.naimacanada.ca, for more information on insulation products, benefits and resources, including training videos on installation.
And consider this: Updating your home's insulation would make a great new years' resolution.
Here's to a greener 2008!
Insulation facts
NAIMA Canada notes that, "Inadequate insulation is one of the main reasons why the average home can lose up to 50 per cent of its energy."
It therefore pays to upgrade the insulation. Doing so in your attic and main-floor walls alone can result in an energy cost savings of between 5 and 10 per cent. (Projected savings are based on "Hot 2000" program calculations and represent a single-family detached home in Toronto, upgraded from 2006 Ontario Building Code standards.)
