Is Your Garage Door Weatherproof? Why a New Bottom Seal Matters

September 12, 2026 New garage door bottom weather seal installed in Sacramento

A gap of just a quarter-inch under your garage door is enough for mice to get in. Here's what a bottom seal actually does, and when it's time to replace it.

The Daylight Test

If you can see daylight under your closed garage door, the bottom seal has cracked, flattened, or pulled away from the track — and it's letting in more than just light. Drafts, dirt, water and pests all use the same gap.

A gap of just a quarter-inch is enough for mice to squeeze through. On a hot Sacramento summer day that same gap is pulling 100-degree air into your garage, and during a winter storm it's the path rain takes to pool inside.

What a Bottom Seal Actually Does

The bottom weather seal (also called an astragal) is the rubber or vinyl strip that runs the full width of the garage door's bottom edge. It compresses against the floor when the door closes, forming the only flexible barrier between the inside of your garage and the outdoors.

Blocks drafts that push conditioned or heated air out of an attached garage and the rooms next to it.
Keeps rain and irrigation runoff from pooling inside during Sacramento's wet winter months.
Physically blocks the most common entry point rodents and insects use to get into a garage — a torn or gapped seal is often the actual "hole" homeowners can't find.
Reduces dust and debris blowing in during dry Central Valley summers and wildfire smoke days.

Signs Your Weather Seal Needs Replacing

Most homeowners don't think about the bottom seal until something comes in through the gap. Here are the signs we look for on every service call:

Visible daylight or a gap under the closed door.
Seal is cracked, flattened, or brittle to the touch.
Chew marks or gnawed sections — a sign rodents have already been testing it.
Water intrusion or a damp line just inside the door after rain.
Draft you can feel standing near the bottom of the door.
Seal has pulled loose from the track or won't stay seated.

Benefits of a Professional Weather Seal Install

A bottom seal swap looks simple, but the difference between a seal that works and one that looks installed comes down to full-width contact and the correct profile for your door's track.

Pest prevention: a professional-grade seal creates full, even contact along the entire width of the door — a gapped or unevenly seated DIY seal still leaves entry points rodents will find.
Draft and energy savings: a properly seated seal closes the gap completely, which matters most on doors that share a wall with living space.
Electrical and moisture protection: many garages house the electrical panel, water heater, or outlets low on the wall — a sealed door threshold reduces water intrusion risk near that equipment during storms.
Correct fit for the track type: seals come in different profiles (bulb, T-style, bead) sized to specific track types; the wrong profile can look installed but not compress properly, which defeats the purpose.
One visit, full inspection: a pro typically checks the track, rollers and bottom bracket at the same time, catching a bent track or worn roller that would keep even a new seal from sealing evenly.

DIY vs. Professional Replacement

A basic bottom seal swap is a realistic DIY project for a handy homeowner who has the door's exact track and retainer style and the correct seal profile on hand. But here is where it commonly goes wrong: buying the wrong profile for the retainer track, cutting the seal short, or not seating it fully along the whole width — all of which leave gaps that look fine from a few feet away but still let drafts and pests through.

Professional installation guarantees full-width contact, uses heavy-duty commercial-grade seal material rather than hardware-store-grade, and takes minutes as part of a same-day visit.

Brands We Stock Seals For

A&M carries and installs heavy-duty replacement bottom seals for all major manufacturers — Wayne Dalton, CHI, Clopay, Amarr, Martin Doors, Unique Doors, Overhead Door, Haas Door, Raynor and AlumaDoors — matched to the door's specific track and retainer profile, with same-day installation across the Sacramento Valley.

Frequently asked questions

How do I know if my garage door seal is bad?

Daylight under the door, a visible crack or flat spot in the rubber, or a draft you can feel near the floor are the clearest signs. If you can see light when the door is closed, the seal has failed.

Can a garage door seal really keep mice out?

Yes. A properly seated seal closes the gap mice use to get in; a torn or gapped seal is one of the most common entry points in an attached garage. Rodents only need a quarter-inch gap.

How often should a garage door weather seal be replaced?

Most seals last 5–10 years depending on sun exposure and how often the door cycles. Driveways with hot summer sun exposure often see cracking sooner.

Does a new weather seal actually lower energy bills?

It won't replace full door insulation, but closing the draft gap at the bottom reduces the amount of outside air pushing into an attached garage, which helps rooms next to it stay more stable.

Do all garage doors use the same seal type?

No. Seals come in different profiles matched to the specific bottom track or astragal retainer on the door, which is why the wrong seal from a hardware store often doesn't seat correctly.

Can a bad seal cause water damage inside the garage?

Yes. A gapped or flattened seal is a common way rain and sprinkler runoff gets under the door, especially on driveways that slope toward the garage.

Is weather seal replacement covered under a garage door warranty?

The seal itself is a wear item and typically isn't covered long-term, but professional installation is usually backed by a workmanship warranty on the labor.

Talk to a local technician

Free estimates and upfront pricing on garage door and gate repair anywhere in Greater Sacramento — 24 hours a day.

Call (279) 900-6320 Request a free quote