If your heating bill is driving you up the wall, it may be time to check for air leaks. Sealing your house’s envelope can lower your electric bills and ensure your residence is more energy-efficient, which benefits your wallet and the planet.
Learn all about a building’s envelope and ways to optimize your climate control by insulating your home.
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What Is a Building Envelope?
A building envelope is the “joints” where walls, windows, doors and frames join. This resembles an envelope’s framework, explaining the name.
Air leaks in or out of the building via these spaces, causing a loss of climate control and raising heating or cooling costs in winter or summer.
How to Test Your Home’s Envelope
When you suspect your house has hidden gaps, you can consult a weatherizing specialist with unique equipment to check your home for leaks. However, if you intend to do a DIY job, you can try these three popular methods to test the home envelope:
- A blower door: You can rent a blower door, which is a high-powered suction pump connecting to one doorway with a sealed-off panel. When you close all windows and doors and engage the blower, it sucks enough air from your home to lower the internal air pressure. Any leaks will produce a hissing sound or a draft as the air gets sucked into the house through cracks, gaps and holes. Mark these for repairs.
- A smoke test: The smoke test requires a cool, windy day. Close all doors and windows, shut off the furnace, and switch on all vents or extraction fans. Now, light a couple of incense sticks and stroll through each room, moving past walls, windows and openings. You can locate drafts when you see the smoke trailing toward a wall or blowing away.
- A light test: This test relies on the saying “light at the end of the tunnel.” Simply draw the curtains and blinds at night while lighting bright lights in your home. Work from room to room, watching from the outside for any slivers of light or spots that show a gap in the walls, frames or roof.
9 Strategies to Seal Your Home’s Energy Envelope
You’ll hear about many insulating materials, including caulking, weatherstripping, spray foam, cellulose and glass-free insulation. Larger gaps may encourage you to take out shares in expanding foam sealant. What products do you use where?
1. Window and Doorframes
Window and doorframes do well with either caulking or weatherstripping, though large gaps between the wall and frame could need expanding foam sealant. When caulking, smooth the finish while wet.
If you apply expanding foam, wait until it has dried and hardened, then use a box cutter to cut an even edge. A coat of paint will seamlessly blend the fix with the rest of your home.
2. Insulated Garage Door
The garage door opening is likely the biggest opening of the house, and without a tight-fitting insulated door, it’s a major area of heat loss. The door’s material contributes to the surface’s thermal resistance or R-value. Thicker doors keep heat in for longer.
Insulated doors come with expanding foam injected between the inside and outside plates to boost thermal resistance and provide better temperature control inside the garage. While you can choose a lower R-value rating for a detached garage, one that’s attached to your home lowers its heat profile. Therefore, selecting a rating of R-12 or more is recommended to ensure the opening is adequately insulated.
3. Plumbing and Electrical Access
Next, you should track down all areas where pipes and electrical connections pass through your walls from the outside or the roof’s crawl space. These gaps are more than just a handy passage for the resident mouse — they allow large volumes of cold air to penetrate your home.
Expanding foam is likely your friend here, but if the gaps are enormous, you may want custom plates cut to cover these gaps and finish up with caulking.
4. Double-Insulated Windows
In colder areas, it’s wise to install a weather window or double-glazed layer over existing panes. This creates an insulated air pocket that warms your home. Regular windows have poor heat retention, so they’re likely to radiate the heat from your house quickly.
5. Chimney Seal
Chimneys are always associated with heat, but their flues are often weak spots in your heating envelope. Insulating the flue in the roof space is a good start. In addition, check the steel flue regularly to ensure no rusted cracks form due to the fireplace’s constant heating and cooling. If you don’t use the fireplace, you can make a plug from a thick canvas bag filled with leftover insulation material or even an old blanket, which you stick up the chimney. This effectively cuts off any drafts from above.
You can also change out an unused chimney for a solar version, which can aid in cooling and heating your home with the sun’s power. The design features a vertical shaft that’s coated in a dark material to absorb sunlight, which heats the air inside the chimney. There’s no need for solar panels or costly equipment.
6. Wood Frame vs. Steel Frame
Many renovators consider replacing old wood window and door frames with aluminum or steel, but they should first consider heat retention. Wood is a porous material that creates natural air pockets, which provide more insulation than a solid steel frame.
Since it also expands slightly in damp weather, it fills those micro-cracks better, naturally cutting off airflow. That front door that sticks in cold and rainy weather is actually keeping the cold out.
7. Attic Insulation
Just like people who lose heat through their heads in winter and wear hats to cover up, the house’s attic is a massive source of heat loss. Leaking depends on the type of insulation your home has. If it’s old and tattered, you may have to replace it entirely to restore the building’s envelope integrity.
Cracked roof tiles, loose shingles or rusted roof sheets can all act like a sieve, seeping warm air from your HVAC day and night. Roof joints and areas around windows and chimneys are especially susceptible to damage, so you’ll have to work on the roof. Getting a contractor to help with repairs may be worth it.
8. Foundation
A cracked or leaky foundation can severely limit your home’s heat profile. Cold seeps through the floorboards, so ensure the foundation or basement is correctly sealed and cracks are filled with concrete and waterproof sealant. Inspect these areas seasonally for signs of sagging or cracking to head off major drama.
9. Water Heaters
The water heater or boiler is the most costly home-heating device, and when it’s poorly insulated, it works much harder to heat water to the required temperature. Installing a boiler blanket is a practical way to insulate the tank and maintain temperatures.
Insulate Effectively
With the correct insulation to seal all crevices and openings, your home can achieve a much better energy envelope with minimal heat loss. You’ll feel the difference in your indoor climate and your wallet, and by using less energy, you’re also helping to save the planet one degree at a time on your thermostat.