2026-03-24 6 min read
Here's something most Hooksett homeowners don't think about until late November: their garage door is probably the single largest opening in their home's exterior, and for many houses in town. the colonials and Cape Cods that make up a big chunk of our housing stock. that opening shares a wall directly with heated living space.
A failing bottom seal or cracked side weatherstripping isn't just a minor annoyance. It's a direct channel for cold air, moisture, and the occasional mouse looking for a warm place to spend January. If your garage floor is perpetually damp in winter, or you can feel a draft near the door to your house, your garage door's weatherstripping is almost certainly the place to start.
Weatherstripping isn't one thing. it's a system. There are four distinct points where a garage door can leak air and moisture:
1. The bottom seal. This is the rubber or vinyl strip attached to the very bottom panel of the door. It compresses against the concrete floor when the door closes. It takes more abuse than anything else: repeated compression, contact with road salt dragged in from driveways on Route 3A or Hooksett Road, and freezing to the ground on cold nights.
2. The side seals. Flexible strips running up both vertical sides of the door frame. These block wind-driven rain and drafts. Many older homes in Hooksett have original wood-frame garages where these seals have hardened or cracked over the years.
3. The top seal. The strip across the top of the door opening. Often overlooked, but on windy nights it lets in significant cold air, especially on exposed lots.
4. Between door panels. Each horizontal section of a sectional door has a slight gap where panels meet. Foam tape or V-type weatherstripping can seal these, particularly useful in older doors.
For a broader look at how a well-maintained door protects your home through all seasons, our post on preparing your garage door for storm season covers the full picture.
Not all weatherstripping is equal, and the choice of material matters a lot when you're dealing with southern New Hampshire winters.
Rubber is the best all-around choice for our climate. It stays flexible in cold temperatures, which matters when you're dealing with January mornings in the single digits. Rubber conforms tightly to an uneven floor and doesn't crack the way vinyl can after a few seasons.
Vinyl is more affordable and works fine in milder climates, but it becomes stiffer in cold weather, which means it seals less effectively right when you need it most. If you're on a tight budget, vinyl side seals are a reasonable compromise. just plan to replace them more frequently.
EPDM rubber (the same material used in roofing applications) is a durable option that holds up particularly well against freeze-thaw cycling. If you're replacing a bottom seal and plan to stay in the house long-term, EPDM is worth the extra few dollars.
For homes with an uneven garage floor. common in older construction across Hooksett and over in Goffstown. a T-style or bulb seal works better than a flat blade seal because it can conform to dips and variations in the concrete.
You don't need to be a contractor to assess this. Stand inside your closed garage on a sunny day and look at the perimeter of the door. if you see light coming through anywhere, air and moisture are getting in too. Then:
- Press your hand against the bottom seal when the door is closed. If you feel cold air moving, the seal has compressed beyond usefulness. - Check for cracking or brittleness in the rubber. Old seals will often flake or crumble when bent slightly. - Look for moisture staining on your garage floor near the door. a sign that water is wicking under a compromised bottom seal. - Look at the side seal tracks. if the rubber has pulled away from the retainer or has gaps, it's time to replace them.
Most garage door bottom seals need replacement every two to three years in our climate, more frequently if the door sees heavy use or if the driveway is treated heavily with ice melt.
One specific issue worth mentioning: in Hooksett winters, bottom seals can freeze directly to the concrete floor overnight. This happens when moisture sits at the base of the door and then temperatures drop. If you force the opener when the door is frozen to the ground, you risk tearing the seal completely or, worse, damaging the opener motor or springs.
If your door is frozen shut, use a heat gun carefully along the base, or pour warm water at the seam and wait a few minutes. Never yank on the door or use a pry bar. A replacement seal costs less than $50. A broken spring because you forced it costs considerably more.
Replacing a bottom seal is a straightforward job for a confident DIYer. Side seals are trickier. the retainer tracks need to be properly aligned for the seal to make contact with the door panel evenly. If you have an older door, the tracks themselves may be bent or corroded, and that's a job better left to a professional.
Our service areas page lists all the towns we cover regularly, and if you're not sure whether your door needs a seal replacement, a partial tune-up, or a full inspection, the honest answer is: start with a call. Most weatherstripping issues are obvious in person within a few minutes.
And if you're weighing whether it's worth spending money on an aging door at all, our post on long-term cost benefits breaks down how to think through those decisions without oversimplifying them.
My garage door bottom seal is torn in one spot. do I need to replace the whole thing? Yes, in most cases. Patching a torn seal with tape is a temporary fix that usually fails within a season. Bottom seals are sold by the linear foot and replacing the entire length ensures an even seal across the floor. It's also inexpensive enough that a partial fix rarely makes sense.
Can I install weatherstripping myself, or should I call a pro? A bottom seal replacement is a reasonable DIY job if your retainer track is in good shape. Side and top seals are more involved. if the door frame has warped or the retainer is damaged, you'll need professional help to get a proper seal. When in doubt, a quick inspection costs less than a failed DIY attempt.
How much of a difference does good weatherstripping actually make on energy bills? In an attached garage that shares walls with heated space, the difference is noticeable. Keeping a garage significantly warmer in cold weather. especially relevant during a Hooksett winter that regularly dips below 10°F. reduces the thermal load on your home's heating system. The savings won't pay off in a single month, but over a full heating season it adds up, especially with today's energy prices.