HomeInOn – Insulation options
Optimizing the energy efficiency of your home includes proper insulation.
According to Statistics Canada’s ‘Survey of Household Spending’, the average Canadian home spends about $2,500 on total energy costs. On average, 60 percent of that amount – $1,500 smackers – goes to heat and cool the home. That’s a fair chuck of pocket change. Fortunately, there are a few things you can do to lower your overall energy costs, and keep more of those hard-earned dollars in your pocket – seal, insulate, and maintain.
Topping up the insulation in ceilings, or adding insulation to crawl spaces, attics and basements, is by far the most effective thing you can do. But without sealing around the usual places – windows, doors, receptacles, and plugs – and the less obvious places – plumbing vents, junction boxes, wiring access holes, behind kneewalls, rim joists, and attic access doors – you’ll be working at cross purposes. Before you add any additional insulation to your home, take the time to inspect for possible air leaks, and ‘plug and seal’ them with caulking and/or expanding foam spray. To make it easier to find where your home is losing heat, you can have an infrared scan taken. Contact a local energy auditor or insulation contractor.
Adding insulation won’t just save you money – it will make your home cozier, help reduce noise infiltration, increase the value of your home, and appease Gaia by reducing your contribution to greenhouse gas emissions.
An avid DIYer can install any type of insulation except spray foam – it’s bulky, messy and difficult to spray well. However, for fairly small jobs you can purchase disposable tanks of one- or two-component polyurethane foam. Loose fill insulation is easier to install, though it requires the use of a blower (which you can rent) and a helper to fill and operate the blower hopper. Rigid (foam board) insulation is commonly used in basement renos. It’s not difficult to install, but more involved. Foam board is usually attached to walls with general-purpose adhesive, and then all the seams are taped. Framing is overlaid, the stud cavity is filled with batt or spray insulation, and then drywall or some other sheathing is used to finish the walls. Batt and roll insulation is the easiest to install, though you have to be diligent about doing it properly – not leaving gaps or voids, not overly compressing the batts, and not installing them too loosely between studs or joists. The only equipment you need is gloves, long-sleeved shirt, respirator, and utility knife.
This article provides basic information on the most popular types of insulation commonly available from building supply centers across Canada, along with a handy chart of R-values, to get you set on the right track. If you decide to hire a contractor, ask for references, and make sure you get a written estimate. Don’t hesitate to ask them to explain how they’ll install the product, whether they air-seal while insulating, and make sure you check over the work once it’s completed.
Fibreglass Batts
The most commonly used type of insulation in Canada, fibreglass batts are an economical choice and are fairly easy to install. (Photo by CertainTeed)
Vapour Retarder
A Kraft paper or foil vapour retarder is sometimes attached to one side of fibreglass batts. (Photo by CertainTeed)
Rolled Fibreglass Insulation
Rolls of fibreglass insulation are available in long and wide dimensions, and are great for covering large, at areas. (Photo by Owens Corning)
Premium Batts
Rock wool is stiffer than fibreglass, and can be easier to handle and install. It’s easily cut with a knife. (Photo by Roxul)
Blow It in Place
Blowing fibreglass or rock wool insulation into an area can be very efficient, though a helper is needed to feed the hopper. (Photo by Owens Corning)
Insulation Boards
Extruded polystyrene, commonly found in blue or pink, is strong and dense, and does a pretty good job at blocking moisture. (Photo by Dow)
High-Quality Boards
Polyisocyanurate board ranges from 1/2" to 2-1/2" thick, and typically has a foil facing on both sides. This product is great for blocking vapour and has a very high R-value. (Photo by IKO)
Batts and Rolls
Available as fibreglass, and rock wool (aka mineral wool or stone wool) batts, in 16″ to 24″ widths, 48″ long, and from about 3-1/2″ to 6-1/4″ thick (7-1/4″ for rock wool), and in rolls of the same thickness, 15″ to 48″ wide and up to 100’ long. Generally used unfaced, but also available with a vapour retarder attached to one side – usually Kraft paper or foil. When properly installed, neither of these products will slump appreciably, and they’ll hold their R-value indefinitely.
Traditionally both fibreglass and rock wool contained form- aldehyde as a binder. Health Canada recommends an exposure limit of 40 ppb (parts per billion). Most insulation today has very low levels of formaldehyde – Certainteed products, for example, are in the 11 to 15 ppb range. Quite a few companies, including Johns Manville, Owens Corning, and Roxul, offer formaldehyde-free insulation that uses an acrylic binder.
Fibreglass, the most widely used insulation in Canada, is the economical choice. It’s air and vapour permeable, non- combustible, and won’t rot. It doesn’t support mold growth, but when it does get wet, it takes a while to dry out. While it does serve as a sound absorber, it’s not an effective sound blocker. However, there are various insulating products, like CertainTeed’s NoiseReducer and Owens Corning’s QuietZone batts that are specifically designed to help reduce sound transmission.
Rock wool is the premium choice. It’s made primarily from basalt rock and granulated blast furnace slag, spun into fibers, and can have up to 90% recycled content (compared to fibreglass which can have up to about 70%). It’s noncombustible, vapor permeable, water repellant, fire and mold resistant, and has good sound-absorbing qualities. Because it’s stiffer and denser than fibreglass, many find it easier to install.
Sources: CertainTeed.com, JM.com, KnaufInsulation.ca, OwensCorning.com, Roxul.com
R-Value
You’ll see the term R-Value bandied about quite a bit. Essentially it measures how well a material resists the flow of heat. The higher the number, the better able it is to resist heat flow – which is what you want. Thicker insulating materials will have higher R-values, and different types of insulating materials of the same thickness may have different R-values. R-values are often listed per inch of insulating material. For example, fibreglass batts have an R-value of around 3 to 3.7 per inch of thickness, while closed-cell spray foam has an R-value of about 6 per inch.
Loose Fill (Blown)
This is the same material as in fibreglass and rock wool batts, but it’s in a crumbled or chopped form so that it can be blown into hard-to-reach places. It’s widely used in attics, often over a base layer of batts, as it does a super job of filling in crevices. There is also a cellulose-based product made of recycled paper along with various natural additives, that serves as a fire sup- pressant and also controls mold and dust. On the downside, cellulose does absorb moisture and can hold a lot of water.
Sources: Cellulose.com, CertainTeed.com, JM.com, OwensCorning.com, WeatherShield.ca
Rigid (Foam board)
Available as expanded polystyrene (EPS), extruded polystyrene (XPS) and polyisocyanurate (ISO) in boards 24″ × 96″ and from 1/2″ to 2-1/2″ thick. They’re typically used to insulate basement walls (both inside and out), and they provide a superior air barrier if the seams between sheets are carefully sealed with caulk or tape. Most EPS and XPS boards contain the highly toxic fire retardant hexabromocyclododecane (HBCD), while EPS doesn’t contain the ozone-depleting hydrochlorofluorocarbons (HCFCs) found in XPS. However, at least one company (Dow) has shifted to a nonhazardous polymer fire retardant.
EPS is the least expensive, the most vapour permeable and has the lowest R-value. It’s usually white, and food and beverage coolers used to be made of this type of material. XPS (the common blue or pink foam board) is stronger, denser, and blocks moisture better than EPS. ISO typically has a foil facing on both sides, which serves as a vapour barrier, and it has the highest R-value of any insulation (less so in very cold tempera- tures). It’s more fire resistant than EPS and XPS, and doesn’t contain HBCD, but is much more water permeable. Note: Roxul’s ComforBoard is not a foam board, but rather a rigid sheathing made of rock wool.
Sources: Dow.com, IKO.com, JM.com, OwensCorning.com
Insulated Siding
Another way to add extra insulating value to your home is with insulated vinyl siding. It usually has a layer of EPS foam board fused onto the back of the siding, and adds an extra R3 to your walls. However, it costs more than conventional siding, and because the seams of the insulated siding are not taped, it doesn’t make the home more airtight.
Spray
Available as open-cell polyurethane (OCP) and closed-cell polyurethane (CCP), both are good air and dust barriers – the foam expands to create an airtight seal that won’t shrink, compress, settle, or biodegrade. Sprays also do a good job of reducing sound transmission. OCP has about half the R-value of CCP, and it is permeable to moisture and impermeable to air. CCP is considered the most effective of all the types of insulation, and the most expensive. It’s a very effective vapor retarder, impervious to moisture, and provides greater structural strength than OCP. However, it contains environmentally harmful hydrofluorocarbons (HFCs). Neither contain any recycled content. Because of the difficulty of application, it’s typically installed by insulation contractors. One- and two-component CCP foam kit systems, such as Tiger Foam, are available for small spray jobs.
Sources: Dow.com, JM.com, TigerFoam.ca, Touch-n-Foam.com
Resources
National Association of Insulation Manufacturers of Canada – naimacanada.ca
Thermal Insulation Association of Canada – tiac.ca
Carl Duguay - [email protected]
Carl is a Victoria-based furniture maker and the web editor at Canadian Woodworking & Home Improvement.
