How is a New Brunswick garage door weather sealed?

A New Brunswick garage door is weather sealed using a combination of bottom seals, side and top perimeter seals, and threshold seals — all working together to block cold air, wind-driven rain, snow, and frost from entering under and around the door.

Given NB's winters, where temperatures regularly drop to -20 to -30°C and wind chills push even colder, a poorly sealed garage door is one of the fastest ways to lose heat, damage stored vehicles, and create ice buildup on your garage floor. Getting the sealing system right matters whether your garage is heated or unheated.

The Four Sealing Components

Bottom seal is the most critical piece. It runs along the bottom edge of the door panel and compresses against the floor when the door closes. The most common type is a rubber or vinyl T-slot seal that slides into a channel on the bottom door section. In NB's climate, look for a seal rated for cold temperatures — cheap vinyl seals become brittle and crack at -20°C, losing their flexibility and their ability to conform to an uneven floor surface. A bulb-style or double-lip bottom seal performs better in cold weather than a flat wiper style. Expect to replace the bottom seal every 5-10 years depending on use and UV exposure.

Perimeter seal (side and top) attaches to the door frame (the stop moulding) rather than the door itself. When the door closes, the door panel presses against this foam or rubber seal, closing the gap between the door and the frame. In NB, a closed-cell foam perimeter seal outperforms open-cell foam because it does not absorb moisture and compress permanently over time. The side seals take the most abuse from wind pressure — in coastal communities like Saint John or Shediac, a heavier-gauge perimeter seal is worth the modest extra cost.

Threshold seal is installed on the garage floor itself, directly beneath where the bottom of the door lands. It creates a raised rubber or vinyl ridge that the door seal presses down onto, improving the bottom seal's effectiveness significantly — especially on floors that are not perfectly level or that have settled unevenly over time. A threshold seal is particularly useful in NB garages where snowmelt and rain regularly run toward the door opening. It costs $50-$150 in materials and is one of the most effective DIY weatherproofing upgrades you can make to an existing garage.

Door panel insulation and sealing is worth mentioning separately. The door panels themselves can be a significant source of heat loss if they are non-insulated steel. An insulated garage door with an R-16 or higher rating dramatically reduces cold air transmission through the door surface itself — this is different from the perimeter sealing but works together with it. If your garage is heated or attached to your home, an insulated door is strongly recommended for NB's climate.

NB-Specific Considerations

Ice buildup at the bottom of the door is a common NB problem. When snowmelt or rain freezes overnight, the bottom seal can freeze to the floor, and forcing the door open tears the seal. A threshold seal helps by elevating the contact point slightly. Applying a thin coat of petroleum jelly or silicone spray to the bottom seal in late fall reduces freeze-bonding. Never use salt or calcium chloride directly on rubber seals — it accelerates deterioration.

Wind-driven snow infiltration around the sides of the door is another NB reality, particularly in northern communities like Bathurst or Campbellton. If you are seeing fine snow dust inside the garage after a blizzard, the perimeter seals are either worn, compressed flat, or the door is slightly out of square in its frame. A garage door that has shifted due to frost heave in the foundation can develop gaps that no seal will fix until the underlying alignment issue is corrected.

DIY vs. Professional

Replacing bottom seals, perimeter seals, and threshold seals are all reasonable DIY projects. Bottom seal replacement takes about 30-60 minutes with basic tools — the old seal slides out of the channel and a new one slides in. Perimeter seals are stapled or nailed to the door stop and can be replaced in an afternoon. If the door itself is misaligned, binding, or not closing squarely, that is a job for a garage door technician — adjusting spring tension and track alignment involves components that can cause serious injury if handled incorrectly.

Need help finding a garage door professional in your area? Browse contractors through the New Brunswick Construction Network at newbrunswickconstructionnetwork.com.