2026-03-27 6 min read
Sharon, NH is a small, quiet town. fewer than 400 homes spread across 14 square miles, most of them sitting on sizeable wooded lots. The housing stock here is a mix of older New England colonials, post-and-beam builds, and contemporary homes with passive solar design. What nearly all of them share is a garage door that takes a beating every single winter.
The Monadnock Region gets a genuine continental winter: months of temperatures hovering in the teens and twenties, regular freeze-thaw cycles through late February and March, and snowfall that accumulates and refreezes at the base of garage doors. None of that is great for weatherstripping. the rubber and vinyl seals around your door that are the first line of defense against all of it.
Most homeowners replace their weatherstripping only when it's completely falling off. By that point, cold air, moisture, and rodents have likely been getting in for a while. Here's how to stay ahead of it.
A properly weatherproofed garage door has seals in four places:
Bottom seal. The strip attached to the bottom edge of the door that presses against the floor when closed. This is the most important seal and the one that fails most often. It takes constant compression, scraping across concrete, and in Sharon winters, it regularly freezes to the ground.
Side seals (stops). The vertical strips attached to the door frame on the left and right. These close the gap between the door panel and the frame.
Top seal. The horizontal strip along the top of the frame that closes the gap at the header. Often overlooked, but a significant source of cold air infiltration in older homes.
Panel weatherstripping. On sectional doors, small seals between each horizontal panel help reduce air movement through the door itself. These degrade slowly and are often ignored entirely.
For most Sharon homes, the bottom seal and the side stops deserve the most regular attention.
You don't need to be a technician to spot failing seals. A few simple checks will tell you what you need to know:
- Stand inside your garage with the door closed and the lights off. If you can see daylight around the edges or underneath the door, the seals are failing. - Run your hand along the bottom edge and sides on a cold day. If you feel cold air movement, you have gaps. - Look at the bottom seal directly. Cracking, flat spots, hardening, or pieces tearing away are all signs it needs to go. - Check the floor just inside the door after a snowstorm. If there's a thin line of snow or moisture just inside the door, the bottom seal isn't seating properly.
Hardening and flattening are the most common failure modes in New Hampshire's climate. Rubber and vinyl both become brittle in sustained cold, losing the flexibility they need to compress and form a proper seal.
Not all weatherstripping holds up the same in a climate like Sharon's. Here's what actually matters:
Rubber is the best all-around choice for this region. It's durable, flexible in cold temperatures, and handles repeated freeze-thaw cycles better than vinyl. If you live in an area with freezing winters. and Sharon most definitely qualifies. look specifically for rubber stripping rated to stay flexible at low temperatures. Standard rubber without that cold-weather rating can still crack and harden.
Vinyl is less expensive and resists mold and mildew well, but it tends to degrade faster in extreme cold. It's a reasonable choice for the side and top seals where it's less exposed to compression and scraping, but it's not ideal for the bottom.
EPDM rubber is a synthetic rubber compound that stays soft in both cold and heat. If you're replacing your bottom seal and want it to last, EPDM-based seals are worth the slightly higher cost.
For homes with uneven concrete floors. which is common in older Sharon properties. a T-slot bottom seal gives you more flexibility to accommodate surface irregularities than a simple flat bulb seal.
Bottom seal replacement is a manageable DIY project for most homeowners. The seal slides into a retainer track along the bottom of the door. you slide the old one out, slide the new one in, and trim to length. The main thing to get right is the measurement and material choice.
Side and top stops are also DIY-friendly. The old stops are typically nailed or stapled to the door frame, and new ones can be cut to length and reattached with roofing nails or screws.
Where it makes more sense to call in help: if the door frame itself is damaged, rotted, or misaligned, seals won't work properly regardless of the material you use. Similarly, if your door isn't closing flush. sitting higher on one side, or not making even contact across the bottom. that's a door alignment issue, not just a seal issue. Take a look at our garage door safety testing guide for help identifying whether your door is balanced and closing properly before you invest in new seals.
Sharon Garage Doors can inspect and replace weatherstripping on any door type as part of a standard tune-up. If you're not sure what you're dealing with, view our service options or get in touch directly.
This is specific to New Hampshire winters and worth calling out. When snow melts and refreezes under the door, the bottom seal can freeze solid to the concrete. Forcing the door open in that condition will tear the seal. sometimes the entire retainer. right off the door.
If your door is frozen to the floor, use warm water or gentle chipping to break the seal from the outside before trying to operate the door. Never use rock salt or ice melt directly on a steel door. it causes corrosion. After freeing the door, dry the threshold area thoroughly before the temperature drops again. Homeowners in Greenville and Milford face the same issue. it's a regional reality, not a defect.
Regular lubrication of the bottom seal with a silicone spray helps reduce freeze-down by keeping the rubber pliable and slightly resistant to bonding with ice.
In a climate like Sharon's, bottom seals typically last 3,5 years with regular use before they crack or flatten enough to lose their seal. Side and top stops can last longer. often 7,10 years. but should be inspected annually for brittleness and gaps.
Yes, particularly if your garage is attached to the house. Sealing gaps around the door reduces cold air infiltration into the garage, which in turn reduces heat loss through the shared wall. It's one of the more cost-effective energy improvements available to homeowners.
For best results, remove the old seals completely before installing new ones. Installing over damaged or compressed old material usually results in an uneven surface that the new seal won't compress against properly. and you'll end up with the same gap problem.