Insulation

Upgrading attic or basement insulation yourself might only cost a few hundred dollars. Hiring contractors is more expensive, as is upgrading external wall insulation. Upgrading your insulation could cut your home heating bills by up to 30 per cent. Government rebates are available, click here for more info.	Some research and perhaps a fair amount of effort, if you do it yourself.	Upgrading your insulation can reduce your greenhouse gas emissions by up to 0.5 tonnes per year.

Why should I upgrade the insulation in my home?

Space heating is easily the biggest energy user in Alberta homes, so upgrading your insulation is a very cost-effective way to cut your energy bills – by perhaps up to 30 per cent – and your greenhouse gas emissions. There’s little point investing in a high-efficiency furnace if much of the heat it produces escapes from a poorly-insulated house. A well-insulated house will also result in more evenly heated rooms and keep your home cooler in the summer.

How can I tell if I need to upgrade my home's insulation?

Telltale signs in winter include unevenly heated rooms, external walls and basement floors that are cool to the touch and, most of all, abnormally high heating bills. A poorly-insulated house will also feel unusually hot in the summer. Generally speaking, the older the house, the less likely it is to be properly insulated, unless it has been renovated in recent years.

The most comprehensive way to determine if your house is adequately insulated is to get a professional energy evaluation. You can also get a good idea of your home’s insulation quality by doing a visual inspection. Start by checking the attic’s insulation, which should be roughly 40 centimetres (15 inches) deep; every inch of insulation is equivalent to an R-value of about three (see below for recommended R values). It’s more difficult to determine how much is in your walls, though any insulation between studs in undeveloped parts of your basement is an indicator of what was used in upper floors. It’s easier to see what, if any, insulation exists in undeveloped areas of the basement and crawl spaces.

How much insulation do I need?

Insulation is measured by its thermal resistance, or R, value, which is the insulating material’s resistance to heat flow. The higher the R value, the slower the heat transfer through the material and the better the material’s insulating ability.

In Alberta’s climate, the following insulation levels are now recommended:

• Attic – R-50
• External walls – R-20
• Basement external walls – R-20

What area of my house should I tackle first?

To maximize the energy-efficiency benefits, you should upgrade the insulation in your entire house. It’s important to realize that heat escapes towards cold, meaning it can as easily be lost sideways through the walls and downwards through the basement floor as upwards through the roof. In other words, if you only insulate one area, heat will still be lost in under-insulated areas. For the same reason, it’s also important to thoroughly seal all your home’s air leaks, which are the un-insulated gaps where cold air can get in and warm air escape; they can represent upwards of one-third of the total heat loss in a house. For more information on reducing air leakage in your house, click here.

If you have to choose, it’s best to initially tackle areas where it’s easiest and most cost effective to upgrade the insulation. That typically means the attic and basement, where it’s generally more straightforward to access insulated areas and add or replace insulation. It’s usually more difficult and expensive to re-insulate external walls, a job often best saved for major renovations when drywall or exterior siding is being removed.

What's involved in upgrading my attic insulation?

The quickest way is to have cellulose fibre insulation – finely shredded newsprint, chemically treated to resist fire and mould – or fibreglass loose fill blown in to cover existing insulation; the small particles flow well into gaps such as those around ceiling joists. Just make sure the insulation is not blocking airflow vents in the soffits. A slightly less expensive alternative is to lay batts of blanket insulation – either fibreglass or mineral wool – on top of existing attic insulation.

How about the basement?

If external basement walls have been framed but not drywalled, you can easily install, or upgrade, blanket insulation between the studs. Frames of rigid polystyrene insulation can be placed against concrete walls, though it must then be covered by a fire-resistant material such as drywall. Slab-on-grade floors can also be covered with rigid insulation. Note: When insulating basements, care must be taken to avoid moisture buildup against the inside wall.

What about external walls on the main or upper floors?

If you live in an older house with no external wall insulation, you can have cellulose or glass fibre insulation blown into the wall cavities through holes drilled into the drywall between the studs – though all these holes must then be patched. It’s more difficult to effectively add blown insulation to wall cavities that already contain some insulation.

If you are doing renovations where the drywall is being replaced, you can more easily insulate walls from the inside with blanket or rigid polystyrene insulation or with extruded polyurethane, which while thinner insulates well because it seals potential air leaks. If you’re removing or replacing external siding, rigid polystyrene insulation can be added from the outside. The advantage of polystyrene, in both cases, is it can form a continuous layer of insulation over the studs, which are otherwise an un-insulated source of heat loss.

Are there other areas of the house that need to be better insulated?

It’s probably worth insulating basement air ducts, the topside of attic hatches and around plumbing stacks that enter the attic. On external walls, insulating gaskets can be placed behind electrical receptacles and light switch cover plates.

How much of this work can I do myself?

Competent do-it-yourselfers can readily add blanket insulation in attics and between exposed studs and can install rigid insulation against exposed walls. Contractors are recommended, and sometimes required, for adding blown or extruded insulation.

Installing insulation correctly is critical so as to avoid air-leakage gaps and potential moisture problems. Note: as a rule, all batt insulations require a vapour barrier to prevent air movement, while rigid insulations do not.

When installing fibreglass or mineral wool insulation, do-it-yourselfers should protect themselves – against loose particles that can irritate the skin, eyes and lungs – by wearing goggles, a dust mask, gloves and long-sleeved shirts or jackets. In older homes, take care not to disturb any asbestos-containing vermiculite insulation and hire qualified contractors if its removal is necessary.

How do I find qualified contractors?

Check your local Yellow Pages, and get quotes and references from at least two contractors. Ask if they specialize in insulation installation and, if so, in particular types of insulation. Also ask if they will patch any drywall holes drilled to blow insulation into exterior walls.

How much will it cost?

Do-it-yourselfers might be able to upgrade insulation in attics or open basements for as little as a few hundred dollars in materials, depending on the type of insulation they use and the square footage covered. Hiring someone to blow cellulose insulation into your attic can often cost less than $1,000 and typically takes only a few hours. Adding insulation to external walls can be considerably more expensive, especially if a contractor is hired.

If I fully upgrade my home's insulation and close all the air leaks, could I run into air quality problems from a house that is too tightly sealed?

That is possible. If you are fully sealing the building’s envelope, it’s perhaps worth installing a heat recovery ventilator (also known as a heat exchanger), which allows fresh, filtered air to steadily flow through your house, while transferring heat from outgoing air to incoming air.