What a Technician Finds on a Typical Seal Call
The call usually starts the same way: "I can see daylight under my garage door" or "There's a line of dirt and dead leaves just inside the door every morning." On the service visit, it's almost always the same culprit — a bottom seal that's cracked, flattened, or torn loose from the track, sometimes with a visible gap big enough to slide a hand under. In this part of Michigan, road salt and sand tracked in off winter roads chew through rubber faster than people expect, and the freeze-thaw cycle each spring stiffens and cracks seals that were already on their last leg. By the time a homeowner notices mouse droppings near the water heater or a draft strong enough to move a cobweb, the seal has usually been failing for a season or two.
Why This Matters Before Winter and Mud Season
A worn bottom seal does more than let in cold air. It's the main barrier against wind-driven snow, spring thaw runoff, dust, and the mice and spiders looking for a warm, dry spot once temperatures drop. Side and top weatherstripping do the same job around the rest of the frame. Replacing these is one of the cheapest fixes in garage door maintenance — usually $15 to $40 in parts for a single-car door — and it can meaningfully cut drafts into an attached garage, which matters a lot once overnight lows start dropping toward single digits.
Tools You'll Need
- Tape measure
- Utility knife with fresh blades
- Flathead screwdriver or trim pry bar
- Replacement bottom seal (bulb-style or T-style, matched to your existing track)
- Replacement weatherstripping for the sides and top (if flush-style, it's usually nailed or stapled with a retainer strip)
- Channel-lock pliers (for pulling an old T-style seal free)
- Work gloves
- Shop vac or stiff broom
- Clamps or locking pliers to hold the door in place while you work
Step-by-Step: Replacing a Bottom Seal
- Identify your seal type. Look at the track along the bottom of the door. Most residential doors use either a bulb seal (a rounded rubber bead that slides into a retainer channel) or a T-style seal (shaped like the letter T, locking into a routed slot in the door's bottom panel).
- Measure the door's width so you buy a seal long enough, with a few extra inches to trim.
- Raise the door partway and secure it with clamps or locking pliers on the track so it can't drop while you're working underneath.
- Pull the old seal out by hand or with pliers, working from one end to the other. If it's brittle and breaks apart, use the utility knife to cut away any stuck fragments.
- Clean the channel of dirt, old adhesive, and grit with a shop vac or brush. A dirty track will keep the new seal from sitting flush.
- Cut the new seal to length, leaving an inch or two of extra material on each end.
- Feed the new seal into the track, starting at one end and working it in gradually across the full width rather than forcing one section at a time.
- Lower the door slowly and check for even contact with the floor — no daylight gaps, no spots where it's crushed and bulging.
- Trim the excess flush with the edges of the door once you're satisfied with the fit.
Step-by-Step: Replacing Side and Top Weatherstripping
- Pry off the old retainer strip or molding holding the weatherstripping in place.
- Remove the old strip and clean the frame surface.
- Cut new weatherstripping to match each section (two sides, one top).
- Tack or staple the retainer strip back over the new material, checking that the door closes against it evenly along its full length.
- Open and close the door a few times, checking by eye and by hand for any section that doesn't make contact.
What's a DIY Job, and What Isn't
Replacing a worn bottom seal or basic weatherstripping on a flush-panel door is a reasonable weekend project for most homeowners — it's inexpensive, low-risk, and doesn't involve the spring or cable system. Where it's worth calling a technician instead:
- The seal won't stay seated in the track, which usually means the track itself is bent or the panel is slightly warped
- The garage floor is visibly sloped or uneven, which may call for a threshold seal installed along the floor rather than just the door
- You have an insulated door with a proprietary retainer system that doesn't match standard hardware store seals
- After replacing the seal, the opener struggles to close fully or reverses unexpectedly — this often means the force or limit settings need to be readjusted for the new resistance
When to Call Chelsea Garage Door
If you've replaced the seal and still feel drafts, see water intrusion during spring thaw, or notice the door isn't closing flush, it's likely a track alignment or panel issue rather than the seal itself. Our Preventive Maintenance visits include a full check of seals, tracks, and hardware so small gaps get caught before winter, and if the opener's force settings need recalibrating after a seal swap, our Opener Installation & Repair service handles that safely. If you're anywhere from Chelsea to Dexter, Manchester, or Saline and want a garage that's actually sealed up tight before the first snow, give Chelsea Garage Door a call.