Most people notice a drafty garage door when they start feeling cold air coming in along the floor or see frost forming where the door meets the concrete. In an Ottawa winter, it’s easy to assume that’s just part of having an attached garage. But if cold air is getting through, the bottom seal may not be the only thing causing the problem.
The Bottom Seal Can Wear Out Over Time
The bottom seal is made of rubber or vinyl and presses against the concrete every time the door closes. Over time, sun exposure can make the material less flexible, while cold temperatures can make it more brittle. A seal that once compressed against the floor may eventually stay flattened, crack, or lose its ability to close the gap.
Road salt, moisture, and grit tracked into the garage can add to that wear, which can be especially hard on seals through an Ottawa winter. The condition of the concrete can matter too. If the driveway or garage floor has a slight dip or high spot, a seal that no longer flexes enough to follow those changes can leave a gap even when the seal isn’t visibly damaged.
Side and Top Seals Can Also Cause Drafts
The seals along the sides and top of the garage door are easy to overlook because they aren’t in direct contact with the floor. If the draft seems to be coming from the sides or top rather than along the floor, the perimeter seal may be the source.
These seals can deteriorate from UV exposure, temperature changes, and repeated compression. Small gaps aren’t always obvious, so check the seal around the full perimeter of the closed door, especially on a cold day when drafts are easier to detect.
How to Find Where the Draft Is Coming From
Start by closing the garage door and checking for visible daylight around the bottom, sides, and top. You can also run your hand near the edges of the closed door to feel for cold air coming through. Pay particular attention to the bottom seal, looking for sections that are cracked, flattened, pulled away, or no longer making consistent contact with the floor.
If the seals appear to be in good condition but you’re still getting a noticeable draft, the problem may not be the seals alone. Door alignment, gaps around the frame, or other areas of the garage can also allow cold air in. In that case, the source of the draft may need a closer inspection.
What a Failing Seal Can Cost You
A gap at the bottom or edges of the door can cause more than a draft:
- Anything stored near the garage floor is more exposed to cold, moisture, and debris when the door doesn’t seal properly
- In an attached garage, a consistently cold garage can increase heat loss through the shared wall and make the adjoining space harder to keep comfortable
- Snowmelt and rain can find their way past a deteriorated bottom seal, particularly where the driveway or garage floor slopes toward the door, leaving standing water or ice at the threshold during winter
- That moisture can accelerate rust on tracks, brackets, and other hardware near the base of the door
- Gaps let in debris, dust, and in some cases pests along with the air
At that point it’s not just a seal problem anymore, it’s a hardware one too.
Why Seal Problems Can Go Unnoticed
Seal wear usually happens gradually, so it can be difficult to notice from one season to the next. A small gap may not seem significant until a particularly cold stretch makes the draft much more noticeable. A quick garage door inspection before winter can catch a deteriorating seal before the problem becomes more obvious.
Choosing the Right Garage Door Seal
Replacing a bottom seal is relatively straightforward, but the replacement needs to match the door and retainer. Garage door seals come in different profiles, including T-style, bulb, and U-style designs, and they are not interchangeable. Some garages also use a separate threshold seal on the floor to provide an additional barrier against water and snow.
Using the wrong profile can prevent the seal from seating properly, leaving gaps even after the old seal has been replaced. If you’re replacing a worn seal, it’s worth identifying the existing profile and retainer before buying a replacement.
Capital Garage Door Ottawa replaces worn bottom, side, and top seals in Ottawa and matches the replacement to your specific door and installation. If you’ve noticed a draft, cold floor, or daylight under the door, contact us for an assessment before the next cold snap.
Frequently Asked Questions
How do I know if my garage door seal needs replacing?
Visible cracking, flattening, or a seal that has pulled away from the door are clear signs that it needs attention. Daylight visible under the closed door or a draft you can feel near the floor are also signs that the seal may no longer be doing its job, even if it still looks intact from a distance.
Does a worn seal really affect my heating bill?
It can have some effect, particularly in an attached garage, but the impact depends on how well the garage and shared wall are insulated and air-sealed. A worn door seal is usually one contributor to heat loss rather than the main cause of a higher heating bill.
How often do garage door seals need replacing in a climate like Ottawa’s?
There isn’t a fixed replacement interval. In Ottawa, exposure to cold, moisture, road salt, sunlight, and repeated compression can cause a bottom seal to wear faster. It’s better to inspect the seal periodically and replace it when it starts cracking, flattening, pulling away, or no longer making consistent contact with the floor.
Can a worn seal cause damage beyond the draft itself?
Yes. Moisture getting past a failed seal can accelerate rust on tracks and hardware near the base of the door. Standing water or ice at the threshold can also create problems over the course of a winter.
What is an under-door air stop?
An under-door air stop is a product designed to block drafts through the gap beneath a door. For a garage door, this usually refers to the bottom weather seal, although some installations also use a threshold seal attached to the floor.
What makes a garage door less drafty?
Keeping the bottom, side, and top seals in good condition is the main way to reduce drafts around a garage door. The seals should make consistent contact with the floor and door frame without gaps. If a seal has hardened, cracked, flattened, or pulled away, replacing it is usually more effective than trying to patch worn material.
