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Home > Energy Efficiency Tips & Tools > Windows and Walls > Insulation Levels
Insulation Levels
How much insulation where?
There are three "hot" spots for effective, energy-saving insulation
from the cold - the attic, the basement and the walls.
Insulation values noted here are recommended for Central and Southern
Ontario. For recommended R-values for Northern Ontario, contact your local
heating and cooling specialist.
The attic
Since warm air rises, the attic can be responsible for 10% to 15% of the
total heat loss in your house. Before you insulate the attic floor, caulk
all around with butyl rubber caulking. Winter is the best time to do this
because you'll be able to feel where warm air is entering from below.
Do not put insulation material within 5 cm (2 in.) of the chimney.
A cautionary note about working in attics: Use sturdy boards to lay across
the joists to get around. Never step between the joists. The ceiling won't
support your weight.
In electrically heated homes, the recommended insulation value for flat
ceilings is R40 and R36 for cathedral or sloped ceilings. Insulation values
of R31 to R38 are recommended if the home is heated with other fuels.
The basement
On average, 20% to 25% of a home's heat loss is in the basement. Properly
insulating it could save you a significant amount a year in electric heating
costs. Most cold air generally leaks in around the basement sill plate
(where the foundation wall meets the first floor wall).
Go around all the outside walls and fill in any gaps with butyl rubber
caulking or an acoustical sealant. Caulk around pipes, holes for wiring
and clothes dryer vents. Any cracks in the foundation walls or slab should
be patched with an appropriate material.
After caulking and weatherstripping, insulate the walls whether from
the inside or the outside of your house. Recommended insulation levels
for basement walls are R19 for electrically heated homes and R12 for homes
heated with other fuels.
| If your seasonal home has an unheated crawl space with an earthen
floor, take these steps to treat it for energy efficiency: |
- If the floor of the crawl space is earth, cover it with a moisture
barrier. Extend the barrier up the inside crawl space walls.
- Insulate the cottage floor from underneath. Install a polyethylene
air/vapour barrier in each joist space. Then install batt insulation
to fill the joist spaces.
- If there are any heating ducts or water pipes in the crawl space,
insulate them. Note that pipe wrap insulation will not necessarily
protect your water pipes from freezing in the winter.
- If it's too difficult to access the crawl space to install batt
insulation, spray-in-place foam insulation can also be used.
|
The walls
Upgrading or installing wall insulation is easily done when renovating
the interior of a house. Once you have the plaster or drywall off the
walls, you can see between the wall studs and joists to determine how
much insulation you'll need.
For electrically heated homes, the recommended insulation value in the
walls is R27 and for homes heated with other fuels it's R22.
| Area Exposed to the Exterior (or unheated space) |
RSI (R-Value) Required (for electric
space heating) |
| Ceiling (Below Attic or Roof Space) |
7.00 (R40) |
Roof Assembly
(Without Attic or Roof Space) |
3.87 (R22) |
| Wall (Other than Foundation Wall) |
4.70 (R27) |
| Foundation Walls (Enclosing Heated Space) |
3.25 (R19) |
Floor
(Other than Slab-on-Ground) |
4.40 (R25) |
| Slab-on-Ground (Containing Pipes or Heating Ducts) |
1.76 (R10) |
| Slab-on-Ground (Not Containing Pipes or Heating Ducts) |
1.41 (R8) |
Replacing windows
The average window lasts 30 years. So, if you're looking at new windows,
you may want to consider those with Low-Emissivity or Low-E glass. Get
more information on energy efficient windows here.
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