How often should I replace garage door weatherstripping in the NB climate?

In New Brunswick's demanding Maritime climate, you should inspect your garage door weatherstripping at least twice a year and plan to replace it every two to three years for the bottom seal and every three to five years for the side and top jamb seals. These intervals are shorter than the five to seven years often cited in generic home maintenance guides because NB's combination of extreme cold, freeze-thaw cycles, UV exposure, road salt, and high humidity breaks down rubber and vinyl seals faster than in milder climates.

The bottom seal (also called the astragal or bottom weatherstrip) takes the most abuse. It contacts the concrete slab or threshold every time the door opens and closes, and in NB, it also endures direct exposure to road salt tracked in by vehicles, pooling meltwater that freezes and thaws against it, and constant compression against ice and debris. The rubber or vinyl material becomes stiff, cracked, and compressed over time, losing its ability to flex and create a tight seal. Once the bottom seal deteriorates, cold air, snow, rain, and rodents find their way into the garage. During an NB winter, a failed bottom seal can raise heating costs noticeably in an insulated garage and allow wind-driven snow to accumulate inside the door — a frustrating mess to clean up repeatedly.

Side and top jamb weatherstripping — the seals that run vertically along both sides of the door frame and across the header — last somewhat longer because they are not in direct contact with the ground. However, NB's UV exposure during long summer days, combined with winter temperature extremes that cause the rubber to cycle between flexible and rigid states thousands of times per season, gradually degrades these seals as well. You will know they need replacement when you can see daylight around the edges of a closed door, feel cold drafts in the garage, or notice that snow or rain is getting past the seals.

Inspection timing matters. Check all weatherstripping in early October before the first freeze and again in early March after the worst of winter. The fall inspection lets you replace any deteriorated seals before they have to endure months of freezing temperatures, while the spring inspection reveals any damage caused by the winter season. During each inspection, look for cracks, tears, compression set (where the seal has permanently flattened and no longer springs back), hardening of the rubber or vinyl, and gaps between the seal and the door or frame. Close the door and check from inside the garage — if you can see daylight around any edge, the seal has failed in that area.

Replacing weatherstripping is a good DIY project and one of the most cost-effective maintenance tasks you can do for your garage. A complete weatherstripping kit for a standard two-car garage door — bottom seal, two side seals, and a top seal — costs $50 to $150 at NB building supply stores. The bottom seal typically slides into a retaining channel on the bottom panel and takes 15 to 30 minutes to replace. Side and top seals are usually nailed or screwed to the door frame and take another 30 to 45 minutes. No special tools are required beyond a utility knife, screwdriver, and measuring tape.

Choose the right material for NB conditions. Silicone-based and EPDM rubber seals outperform standard PVC vinyl in cold temperatures — they stay flexible down to -40 degrees Celsius and resist UV degradation better than vinyl. They cost slightly more but last significantly longer in NB's climate. For the bottom seal, a dual-fin or T-style seal provides better contact and sealing than a simple flat bulb seal, especially on concrete surfaces that may be slightly uneven from frost heave.

Regular weatherstripping maintenance is one of the simplest ways to keep your NB garage comfortable, energy-efficient, and protected from the elements. If your door is old enough that the retaining channels are damaged or incompatible with modern seals, a garage door professional can assess whether the channels can be replaced or whether it is time to consider a new door. Need help finding a professional? New Brunswick Garages can match you for free through the New Brunswick Construction Network.