9 Overlooked Places to Seal Around Your Home for Maximum Efficiency

When it comes to maintaining an energy-efficient home, many homeowners focus on the obvious spots: windows and doors. However, there are several overlooked places around your home where air leaks can easily sneak in, causing drafts and driving up your heating costs. The good news is that these gaps are often simple to identify and seal. In this blog, we'll cover nine commonly overlooked areas that you can address to improve your home's energy efficiency and comfort without the need for major renovations.

Identifying Air Leaks

Locating hidden air leaks in your home may require some detective work, but the Natural Resources Canada Keep the Heat In guide offers practical tips for finding these gaps. While hiring a professional energy advisor or air sealing contractor is always an option, you can also perform a do-it-yourself check with a few simple tools.

Natural Resources Canada suggests using a homemade "leak detector" by lighting two or three incense sticks, which create visible smoke to help you locate drafts. Hold the incense near common leakage spots—such as electrical outlets, light switches, and windows—and watch how the smoke moves. Strong drafts will quickly disperse the smoke and cause the tips of the incense sticks to glow, while smaller leaks will gently pull it toward the source. Choose a windy or cold day when leaks are more noticeable for even more accurate results.

Image from Natural Resources Canada

9 Easy-to-Miss Air Leaks to Seal This Season

There's a seemingly endless list of places to check for air leaks in the Keep the Heat In guide, but here, we'll highlight some spots you likely forgot about! These hidden gaps and cracks may be the culprits behind drafts and energy loss in your home:

Image from Natural Resources Canada

1. Attic Access Doors

Attic access doors frequently have gaps around the frame, allowing warm air to escape into the unheated attic space. Since warm air rises, the attic door becomes a significant area for energy loss during the winter. Plus, the door might not be insulated at all, worsening the problem.

Solution

To prevent drafts, seal the attic hatch like you would an exterior door. Start by applying ALEX PLUS All-Purpose Acrylic Latex Caulk Plus Silicone around the frame and between the casing and the ceiling drywall to create a tight seal. Then, use DRAFT ATTACK Removable Weatherstrip Sealant along the edges of the casing or access panel to stop air from escaping. Finally, install hooks with eyebolts or a latch to keep the hatch securely against the weatherstripping, improving the seal. For extra insulation, consider adding an insulated attic door cover.

2. Ceiling & Recessed Light Fixtures

Ceiling light fixtures, especially recessed or "can" lights, can be a hidden source of air leakage. These fixtures are installed directly into the ceiling cavity, and even small gaps around them can allow air to flow freely. This issue is particularly significant on the top floor of a home, where warm air can escape from the living space into the attic. Recessed lights often have ventilation holes to prevent overheating, which means that the lights themselves can contribute to energy loss.

Solution

To seal around recessed lights, start from within the attic using an insulation cap and BARRIER Multi-Project Foam Sealant to block gaps around the fixture. From the living space, apply ALEX FLEX Premium Molding & Trim Acrylic Latex Siliconized Sealant around the edges of the light to create a tight seal and prevent drafts. This combination helps to keep warm air inside and reduce energy loss.

3. Electrical Outlets & Light Switch Plates

Electrical outlets and light switch plates on exterior walls are often overlooked sources of drafts. Though small, these openings can allow a surprising amount of cold air to enter, particularly during the winter when the difference in indoor and outdoor temperatures is greatest.

Solution

To seal electrical outlets and light switch plates, use NO WARP Window & Door Foam Sealant to fill any gaps around the edges of the outlet box. For smaller gaps around the outlet box or sealing around the edge of the plate, you can apply ALEX FLEX Premium Molding & Trim Acrylic Latex Siliconized Sealant for a long-lasting, airtight seal. For extra protection, consider using foam gaskets behind the plates before sealing the edges to block air leaks effectively.

4. Exhaust Fans and Vents

Exhaust fans and vents, particularly in kitchens, bathrooms, and laundry rooms, are essential for improving ventilation and removing moisture, odours, and excess heat from your home by venting outside. However, these openings can also be a significant source of air leaks if they do not close properly when not in use.

Solution

To prevent drafts, apply DYNAFLEX ULTRA Advanced Exterior Window, Door, Siding & Trim Sealant around the edges of the vent or fan cover to seal any small gaps. Use BARRIER Multi-Project Foam Sealant to fill the voids and ensure proper insulation. Make sure your vent covers have a tight seal and close securely when not in use. This will reduce energy loss and prevent cold air from entering your home.

5. Exterior Wall Penetrations

Exterior wall penetrations, such as holes for wiring, plumbing pipes, electrical cables, and air conditioning pipes, are often overlooked but can be major contributors to air leaks and moisture infiltration. These small gaps around pipes and cables allow cold outdoor air to infiltrate your home and warm air to escape, causing drafts and energy inefficiency.

Solution

To seal these gaps, use the same approach you would for exhaust fans and vents. Apply DYNAFLEX ULTRA Advanced Exterior Window, Door, Siding & Trim Sealant around smaller gaps for a tight seal, ensuring the airflow is blocked. For larger gaps, use BARRIER Multi-Project Foam Sealant to fill the voids, providing a durable and long-lasting seal. This approach will help prevent cold air from entering and warm air from escaping.

6. Pet Doors

Pet doors are convenient, but they often create an unintended air leak. Gaps around the door's frame or between the flap and the frame allow outdoor air to enter, leading to drafts and loss of indoor temperature control. Over time, these seals may degrade or wear down, increasing air infiltration. Even if the pet door is designed to be insulated, the seal may become compromised, especially with frequent use.

Solution

Replace the pet door flap if it's worn or damaged, and seal any gaps around its frame with DYNAFLEX ULTRA Advanced Exterior Window, Door, Siding & Trim Sealant for a durable, flexible seal. Regularly check the pet door's seal to ensure it remains effective over time.

7. Attic Floor Penetrations

The attic is a common area for air leaks, especially where plumbing pipes, wires, and ductwork penetrate the attic floor. These gaps allow heated or cooled air to escape into the attic, which can lead to ice damming on the roof during the winter.

Solution

To seal gaps around pipes and ductwork that penetrate the attic floor, use NO WARP Window & Door Foam Sealant. This low-expansion foam is ideal for filling smaller gaps without damaging surrounding materials. It provides a tight seal to prevent air leaks and improve your home's energy efficiency. Another option would be to use HOME SEAL Minimum Expanding Foam Sealant.

8. Behind Bathtubs & Showers

Behind bathtubs and showers, there are often hidden gaps in the walls or between the fixtures and the surrounding area. These areas are not typically visible but can contribute to air leaks, moisture intrusion, and even mould growth. Gaps around plumbing pipes or where the tub meets the wall can allow warm, moist air to escape or cold air to enter, affecting your home's energy efficiency.

Solution

Use KWIK SEAL ULTRA Advanced Kitchen & Bath Sealant or MONO SILICONE MAX Premium Kitchen, Bath & Plumbing Silicone Sealant to seal gaps between the bathtub, shower, and surrounding walls. Both products are waterproof, flexible, and specifically designed for high-moisture areas, making them perfect for bathrooms. For larger gaps or areas behind plumbing fixtures, NO WARP Window & Door Foam Sealant can be applied to create a more thorough seal, preventing drafts and moisture from infiltrating.

9. Around the Fireplace

Fireplaces are another common source of air leaks. Gaps around the fireplace damper, bricks, or chimney can allow outdoor air to infiltrate your home, causing drafts. The damper controls airflow when the fireplace isn't in use and can sometimes become misaligned or fail to create a proper seal, allowing air to pass through. This can lead to energy loss, especially during the colder months when the fireplace isn't in use, but the gaps around it still allow cold air inside.

Solution

Use HVAC Professional 100% RTV Silicone Sealant around the fireplace damper, flue, and any other cracks to prevent drafts. This sealant is designed to withstand high temperatures and provides a durable, airtight seal.

Sealing air leaks around your home doesn't have to be a daunting task. By targeting these often-overlooked areas, you can prevent drafts, reduce energy bills, and make your home more comfortable year-round. Whether you tackle these projects yourself or hire a professional, the effort will pay off in increased energy savings and a more efficient home. Start with these simple solutions today and make a noticeable difference in your home's comfort and performance this season!

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