Preventing Air Leaks In Your Home Using Spray Foam Insulation
Guardian Energy Technologies explains how to detect and prevent air leaks
If your house has air leaks, your electric or gas bill is going to reflect it pretty quickly. So how do you detect whether you have air leaks in your home and what do you do to prevent them?
A heated house is much like a chimney in that they both hold warm air and are surrounded by cold air. In this, a house will draw air in at the bottom and expel it at the top. All winter, a heated house is trying to push air through the top-floor ceiling into the attic. But when looking for air leaks, in addition to looking in the attic, you want to examine your whole house. Air can leave the house at any point, seeping out your precious warm air and letting in cool air.
So what is the rule of thumb when looking for air leaks? To start, look any place that you may have what is called penetrations or discontinuities. Discontinuities could be where different materials meet, such as between brick and wood siding, between foundation and walls, and between the chimney and siding. Penetrations are places in your home where holes have been drilled for exhaust fans, ducts, chimneys etc. Look for small holes such as those created for electrical wiring and cable installations as well.
Also look for bypasses, which are major air passages from any floor into the attic. Dropped ceilings in the room below will often conceal a direct connection to the attic. Concrete-block party walls between row houses also often move house air into the attic. To look for air leaks in the attic, go up in your attic at night and see if you can see any light shining through from the floor below.
If your home is older, the most thorough way to prevent air leaks in an attic floor is to seal all areas where pipes, ducts, or wiring pass through the floor. Leaks can be sealed with caulking, expanding foam, plastic, or other methods.
Another common area to examine for air leaks is around windows and doors. Starting with your windows, use a waterproof caulk and a caulking gun or simple weather stripping to seal any air leaks you may detect around a window's frame or sill. Replace older windows with ones that offer greater protection from air leaks. Windows marked with the government's Energy Star designation are ideal for insulating your home. The durable materials used in Energy Star window frames provide greater protection against air leaks.
As for your doors, seal drafts that occur around exterior doors. Exterior doors contribute greatly to the problem of air leaks. To help stop drafts you can install a doorsill, weather stripping or a door sweep. Weather stripping or foam insulation strips can be purchased at your local hardware store and is available in varying thicknesses. Choose the thickness based on factors such as how tightly your door closes. If you can look at your door during the day and see light, you may want to use a thicker strip. If your door closes tightly, choose a thinner strip. You can place the strip on the areas where you feel heat loss. Typically on a door, placing the foam insulation strip along the inside of the door jam makes for a neater appearance and less people tend to notice it.
Some of the less obvious places to check for air leaks is electrical outlets and light switches. Sometimes you can place your hand over these areas and see if you can feel a breeze. It is more common to have an air leak at the exterior walls, but depending on how your home was built you may have air leaks at the interior walls as well. Electrical outlet and light switch insulators are a great place air likes to come in. Check these as well.
Next, if your home has plumbing coming in directly from under the house, these areas can be left unsealed. Look under the sink for any holes around the plumbing pipes. Foam insulation can be placed around the pipe to seal small gaps. For larger gaps consider stuffing the holes with steel wool and taping over it with duct tape. This will not only seal the air leak but also prevent mice and rats from chewing through to the inside of your home. If your plumbing pipe has a cap around it, pull the cap away from the wall. If there is a hole, simply use the foam insulation strip to fill in the hole by wrapping a small strip around the pipe.
If you cannot seem to figure out where your house is leaking air, an infrared scan can be used. A professional can examine your house with this heat-sensitive camera and then be able to provide you with where there is at least 10 C difference in temperature between inside and outside air.
If you are on a tight budget, consider closing off rooms that you do not commonly use. Close off air vents in the room and keep the door to that room closed. Place a towel at the bottom of the outside of the door to prevent the cold air from getting to the rest of the house. This works really well and helps to save money on the heating and air bills.
When you seal up your home, you will notice pretty quickly a difference in your energy bill and possibly find yourself a lot more comfortable during the harsh winter and summer months.
The fastest, easiest way to seal those holes is use spray expanding foam. At SprayFoamDirect.com, you can find all the sizes and types of do it yourself spray foam kits you’ll need for these projects.