Bottom Seals and Thresholds

Closing the Gap Along the Floor

The bottom seal is a rubber or vinyl strip held in a channel along the base of the door. When the door closes it compresses against the slab and closes the gap.

It is the hardest working seal on the door and the one that fails first.

How It Fails

It hardens and cracks. Sun and heat drive the plasticisers out of the rubber and it goes stiff, then splits.

It flattens. Years of compression leave it permanently squashed so it no longer reaches.

It tears at a corner, usually where something was driven over it or a rodent worked at it.

It comes out of its channel at one end and hangs.

Matching the Profile

Bottom seals are not universal. The channel on your door takes a particular profile: T-ends, bead ends, or a U-shape retained differently. Fitting an approximate match leaves gaps at the ends or a seal that pulls out.

We match the profile to the channel and size the seal so it compresses properly without dragging, because an oversized seal makes the door harder to close and can confuse the opener’s force settings.

When a Seal Alone Will Not Work

If water still comes in after a new seal, the floor is the problem.

Concrete slabs settle. They crack, they lift at a joint, and plenty were never quite level to begin with. A seal can only compress so far, so where the floor drops away there is a gap it physically cannot bridge.

The answer is a threshold: a rubber strip bonded to the garage floor itself, forming a low ridge that the door seal meets from above. Together they close a gap no seal could manage alone.

A threshold also stops water running in under wind-driven rain, and it gives a definite line for sweeping up to.

Worth Knowing About Thresholds

They are a small step, so if you wheel bins or a motorbike in and out you will feel it. On a garage used as a workshop that is usually fine. It is worth thinking about before rather than after.

The Rust Check

While the seal is off we look at the bottom section, because that is where coastal doors die. Surface bloom is cosmetic and a new seal stops it worsening. Blistered paint with soft metal underneath means the corrosion has gone through.

We will tell you which you have, plainly.

Call Dakotasungardenswinery at (562) 354-2964.