The strip of rubber along the bottom of your garage door does more than you think. When it cracks or shrinks, cold air, rain, snow, and pests all find their way in. Replacing it is one of the cheapest, highest-value bits of garage door maintenance — especially heading into an Ontario winter.
What the weather seal does
Your door has several seals: the bottom seal against the floor, the side and top weatherstripping, and sometimes seals between panels. Together they keep out drafts, water, leaves, insects, and rodents, and help an attached garage hold its temperature.
Signs it needs replacing
- You can see daylight under or around the closed door.
- The rubber is cracked, brittle, flattened, or torn.
- Water, snow, or leaves blow in under the door.
- The garage is noticeably draftier than it used to be.
- You are seeing more insects or mice in the garage.
Why do it before winter
A worn bottom seal lets frigid air pour into an attached garage, pulling heat from the rooms beside and above it and raising your heating bill. A fresh seal also stops the door from freezing to the concrete — a common cause of winter breakdowns. Small job, outsized payoff.
The four seals on a garage door
Most people picture the rubber strip on the bottom of the door and stop there. There are actually four. The bottom seal is the big one, a U-shaped or T-shaped rubber astragal that slides into an aluminum retainer on the bottom section. The side seals and the top seal are the vinyl or rubber strips on the door jambs and header, called stop moulding, that close the gap around the door when it is shut. The threshold seal is the optional rubber ramp glued to the concrete that the bottom seal lands on. Between-section seals on some doors are the fourth, and they are rarely the problem.
Why the bottom seal fails in Ontario
Freeze-thaw is the killer. Water sits in the low spot of the driveway, wicks under the seal, freezes, and bonds the rubber to the concrete. Every time the door lifts in winter it tears a little rubber off. Add road salt, which hardens rubber, and a bottom seal on a busy Ontario door is usually done in five to seven years. The tell is daylight under the closed door, a cold draught across the garage floor, and a bottom section that has started to rust along its lower edge.
Replacing it properly
A bottom seal replacement is a straightforward repair when the retainer is sound. The old rubber slides out of the aluminum track, the new one slides in, and the door is checked to make sure it still closes fully against the floor. Where the concrete has settled and the floor is no longer level, a thicker seal or a threshold ramp closes the gap. Where the bottom section itself has rusted through at the retainer, the retainer will not hold a new seal and the section needs attention. We tell you which case you have before any work starts.
Book a seal replacement in Burlington & the GTA
Pro Entry Garage Doors replaces bottom seals and weatherstripping — often alongside a quick tune-up — across Burlington and the GTA. Call 416-666-6745 or book online.