Frequently Asked Questions - Insulation/WeatherizationCan’t find the answer you’re looking for? Feel free to get in touch with our team.
- I’ve heard that you can make a home “too airtight” – should I be concerned about this?
Today’s homes are more energy-efficient because they follow standards mandating better insulation and airtightness. However, without an appropriately designed, installed and maintained ventilation system, homes can be under-ventilated. Air leakage is not ventilation. A lack of controlled ventilation can lead to a build-up of moisture, odors, bacteria, fungi and combustion gases such as carbon monoxide, carbon dioxide and other pollutants. Ventilation prevents excessive build-up of these and other indoor contaminants that can affect your health and comfort and damage your home.
- Is it better to caulk my windows and doors on the inside or the outside?
Any large gaps on the outside should be weatherproofed to keep rain out, but the inside is generally the best place to caulk to keep the heated air inside, along with any water vapor that could condense in a cold wall cavity.
- Why does moisture form on the inside of my windows in winter, and how can I minimize the amount of moisture?
Condensation will occur whenever warm air hits a cold surface because warm air can hold more water vapor than cold air. If you have single-paned windows, adding storm windows will keep the inner pane of glass warmer and reduce the amount of condensation. Monitoring your indoor humidity and keeping it in the range of 40 – 50% (even less in very cold weather) will also help. You can reduce the humidity level in your home by installing a heat recovery ventilator. A dehumidifier may also help. If you purchase a dehumidifier, be sure to purchase an ENERGY STAR® model as it will use 15% less energy – you can save $10 on energy efficient dehumidifiers during Instant Rebate campaigns.
- What ENERGY STAR® Windows should I buy?
Not all ENERGY STAR choices are the same. Some are more energy efficient than others due to a number of factors, like how much heat they trap inside and how much heat from the sun they let pass through.
Picking the right ENERGY STAR window also depends on where you live. Each of these windows is certified for one or more climate zones in the ENERGY STAR rating system (Zone 1 is the warmest and Zone 3 is the coldest). Newfoundland and Labrador has two climate zones under this rating system and it’s important to know what model is certified for the zone you live in.
- What is ENERGY STAR® Most Efficient?
The ENERGY STAR Most Efficient designation recognizes the most efficient products among those that qualify for the ENERGY STAR label in the current calendar year.
- What are ENERGY STAR® Windows?
ENERGY STAR certified windows are certified by an independent accredited agency for energy performance and insulating glass durability. These certified products often have longer warranties than conventional products. Products that are certified for the zone in which you live—or colder—are the best energy performers of all makes and models on the mainstream market. They meet strict technical specifications for high efficiency—without compromising features or performance in other areas. In fact, ENERGY STAR® certified windows, doors and skylights can decrease your energy costs by about 6% saving you about $75 a year.
- Do windows play a part in insulating my home?
Yes. Today’s windows are better designed and more insulating than ever. Windows fall into two main categories: operable—windows that open in some way, either on hinges or by sliding and non-operable (also called fixed)—those that do not open.
When it comes to energy efficiency, non-operable windows are the most airtight. Among operable windows, hinged windows (awning, casement, hopper or tilt and turn models) are typically the most airtight because the closing mechanism helps pull the window tight against the frame.
In fact, ENERGY STAR® windows, doors and skylights can decrease your energy costs by about 6% saving you about $75 a year.
- Where in the house are air leaks most likely to be found?
A few areas of the house deserve special attention, but don’t limit your detective work to just these places. From inside the main living areas check the following:
- Window panes for tightness, and around both the window sash and the window casing
- Around the door, including the threshold and around the door frame
- Electrical outlets, including those on interior walls
- Exhaust fans and vents. These should vent to the outside and close properly when not in use
- Corners where two walls meet with an imperfect seal
- Light fixtures in the ceiling
- Interior trim and baseboards
- Cracks in the wall finish or ceiling
- The joint where a wood frame wall joins a masonry wall or chimney
- Doors and hatches into unheated attics
- Fireplace dampers and fireplace bricks
- Around chimneys
- Behind bathtubs and under sinks
- Above sliding pocket doors
- Around plumbing pipes and ductwork
- Around the plumbing stack and any other pipes entering the attic
- Around wires or ceiling light fixtures that penetrate the attic
- Around ducting that enters the attic from inside the house
- At the junction of the ceiling with interior wall partitions
- Along any shared walls
- Ceiling areas over bathrooms and stairwells
- Where the wood frame wall (sill plate) meets the masonry (concrete or stone) foundation or where joists penetrate the masonry wall
- Any holes or gaps where the electrical lines, plumbing, gas lines or oil fill pipes go through the external walls
- Leaky ducts or poorly fitted hot air registers or cold air intakes
- Cracks in the foundation wall and slab
- Floor drains
- Can I insulate over recessed lighting fixtures (pot lights)?
Only if the fixtures are Insulation Contact rated fixtures designed to be covered with insulation. Otherwise you should maintain 7.5cm (3 inches) of clearance around the fixtures and leave the top of the fixture uncovered to avoid potentially hazardous heat buildup within the fixture.
The only acceptable way to insulate older, Non-Insulation Contact pot lights is to use a recessed light cover, made of fire safe material or build a sealed box over them and then cover the sides and top of the box with insulation. Minimum box dimensions shall be either 35cm wide x 1.2m long x 30cm high (14″ W x 48″ L x 12″ H), or 53cm wide x 74cm long x 30cm high (21″ W x 29″ L x 12″ H).
- Can I compress a 6 inch (R-20) batt to fit into a 2″x 4″ cavity? Will it be more effective than using a 4 inch (R12) batt?
While insulation batts are easily compressed, the R-value will be significantly reduced – it is best to use the correct thickness and not compress the insulation. You should also avoid storing heavy materials on top of attic insulation for the same reason.
- What is a “vapor barrier” and how important is it?
A vapor barrier is a material that resists the passage of water vapor and is an essential aspect of the insulation project. A properly installed vapor barrier (on the warm side of the insulation) will minimize the chance of water vapor condensing inside your wall insulation, which not only reduces the insulation’s effectiveness but can also cause damage to your home.
- I’m considering having vinyl siding installed on my home. Will this reduce my heating and cooling costs?
Vinyl siding alone is not an insulation material and therefore will not reduce your heating and cooling costs. To improve the energy efficiency of your home, you can install rigid foam insulation on the exterior walls underneath the new vinyl siding. Your municipal council should also be contacted before beginning any home renovations.
- Is it better to insulate the attic floor, the roof, or both?
Unless you are finishing the attic for living space, you should insulate the attic floor to contain the heat within the living space below.
- What is the best type of insulation to use in my attic?
Either loose fill (typically fiberglass or cellulose), batt insulation (usually fiberglass), or spray foam will work well.
Batt insulation is easier to install yourself; if possible, install the new insulation perpendicular to the attic floor joists to reduce heat loss through the joists. Loose fill insulations are typically installed with a blower machine. For a DIY project this can be rented from most hardware stores or you can hire a contractor to complete the work. Spray foam will need to be installed by a trained professional.
- How much insulation should I have in my attic?
Attics should be insulated to a minimum of R-50. We recommend R-60 if you live in Labrador.
- I’ve always heard that “heat rises”. Why do I need to insulate my floors?
Actually, warm air, which is less dense and therefore lighter than cold air will tend to rise above cold air as a result of air pressure. Heat transfer will occur in all directions, because heat moves from areas of high temperature to areas of low temperature, including through the floor of a heated space to an unheated basement.
If your home is built over a crawlspace or unheated basement, you can lose a lot of heat downward through the floors. Insulation will help reduce that loss and also make your floors feel warmer in the winter.
- How much insulation should I have under my floor?
Floors over unheated crawlspaces or basements should be insulated with no less than R-30. Cantilevered floors (overhangs over open air) should have the space between the sub-floor and the soffits fully insulated to at least R-31 and have rigorous air sealing. If your home has a basement containing your heating system or other sources of heat, you should insulate the basement walls to at least R-18, rather than insulating the floor above.
- What is the difference between “R-value” and “RSI value” for insulation?
Both are a measure of how well a material resists the passage of heat, R-Value is the imperial measurement and RSI is the metric equivalent. To convert RSI to R-value multiply by 5.67826; to convert R-value to RSI divide by 5.67826.
- What does the term “R-value” mean?
R-value is a measure of how well a material resists the passage of heat. The higher the R-value, the slower the rate of heat transfer through the insulating material and the more effective insulation is in keeping the home warm in winter and cool in summer. Insulation should always be judged by R-value rather than inches, as different insulation materials have different R-values per inch of thickness.
- If the walls and ceiling of my home are well insulated, do I really need to insulate my basement?
Uninsulated basements are a significant source of heat loss and can account for up to 30% of a home’s heat loss. Basement walls should be insulated to at least R18.