Why You're Losing Money - Finding Air Leaks
Finding Air Leaks
The hardest part about fixing air leaks in your home is actually finding them. Some are easier to find than others, but the biggest ones are always in your attic and basement or crawlspace. My strategy is always to fix the biggest problems first and work my way down the ladder. It's not brain surgery but it works.
Attic Air Leaks
Electrical, plumbing and HVAC contractors use your attic to conceal the wires, pipes and ducts that comprise the mechanical systems in your home. During the construction of your home, they drill and cut holes through the walls to run these pipes and wires. Follow the interior and exterior walls and look for the holes. You'll also want to look for chimneys, furnace flues and lights. This is where most of your largest leaks can be found.
Looking up at the ceiling underneath your attic should help you find the holes. Before you go up into the attic, try to get familiar with your home's layout or just sketch out a floor plan map. This helps you keep your bearings as you ascend into the attic.
While you are in the attic, carefully move over to the areas you've identified and pull back the insulation. If the insulation is black and dirty, you know you've definitely found an air leak.
Don't forget about the attic entrance. It's by far the largest hole in your ceiling. It's usually the size of a window and lets more air into your attic than dozens of small holes and cracks.
Basement Air Leaks
Your basement typically holds most of your HVAC, hot water and electrical equipment. Every major mechanical system in your home needs to enter and exit your home. Most of the holes created during construction are rarely air sealed. These holes go directly outside and allow air to flow through into your home.
Take a flashlight and a stepladder into your basement. Focus your search along foundation wall. Look for any place that wires and pipes that are penetrating the wall. Check to see if the holes have been air sealed with caulk, spray foam or mortar. If you can feel cold air or see sunlight, like in this photo, you have a great chance to save some money.
Now shine your flashlight up over your head. Follow the wires, pipes and HVAC ducts and look for holes in the plywood subfloor. These holes are rarely sealed and you may be able to see up into the wall cavities. Air flows through these holes into your wall cavities and eventually right through your attic without entering your rooms. Each one is like a small chimney that is channelling the air you've paid to heat or cool right out of your house.
Basement windows are notoriously leaky. They are typically single pane with little insulating value. Worse yet, they are probably close to your furnace. They allow hot or cold air to flow directly into your basement where it is sucked into your furnace and blown into your home. This increases the amount of energy your home needs to keep you comfortable. If you only use your basement for storage, consider sealing them off with foam board insulation and spray foam or caulk.
Finally, take a look at your rim joists. The rim joist is located above the foundation wall. It's where the floor joists touch the outside wall. The rim joist is a part of your home that is completely exposed to the outside air and you may find insulation tucked up there. If there is no insulation or if it's fiberglass or rock wool you have another great opportunity to save money. This is because regular insulation doesn't prevent air (or insects and mice) from coming through your wall. You can save a lot of money by air sealing the rim joist bays with rigid foam insulation and caulk or expanding foam like GreatStuff.
Smaller Air Leaks
After you've conquered the attic and the basement, it's time to seal off the smaller holes around windows, doors, baseboards and electrical outlets. Believe it or not, these are not the leakiest parts of your home. I know it feels like it when the wind blows, but this is just the icing on the cake. After you seal off the big leaks, there won't be as much air rushing in through the smaller ones.
Weatherstripping around Windows and Doors
The weatherstripping around windows and doors is a common place for air leaks. Over time, the wear and tear of opening and closing the windows and doors destroys the weatherstripping. Replacing the weatherstripping is an easy do-it-yourself project you can do in a few hours.