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Stand inside your garage on a sunny morning with the door shut and the lights off. Every line of daylight you can see is a gap, and every gap lets in something: winter rain on a westerly, red dust on a summer easterly, dry leaves, cockroaches, the odd redback. A garage door weather seal is the cheapest part on the door and the one that decides whether the garage stays clean.
Do garage doors need weather stripping?
Every door leaves the factory with at least a bottom seal, because slabs are rarely dead flat and the gap a new door closes neatly opens up as the seal hardens. If the garage just holds the car, a sound bottom seal may be enough. If it doubles as a gym, workshop or storage for anything that minds dust, sealing the sides and top as well makes a visible difference. Seals also help a garage hold its temperature, although the panel does most of that work: if you are after a genuinely cooler garage, insulated garage door panels do far more than any seal kit.
The seals on a garage door and the gaps they close
- Bottom seal: a rubber or vinyl strip that sits in a retainer channel along the bottom rail of the door and squashes against the floor. On sectional doors it is usually a bulb, a pair of fins or a U-shaped boot that wraps the rail. On a roller door it is a rubber insert in the bottom bar.
- Side (jamb) seals: a flexible flap on a rigid carrier, screwed to the brickwork or timber frame on each side so the flap rests against the door face when it is closed.
- Head seal: the same idea across the lintel. On a roller door this is often a brush or rubber flap on the outside of the opening that stops wind and rain blowing over the top of the roll.
- Brush seal: dense nylon or polypropylene bristles held in an aluminium strip. Less watertight than rubber, but it bridges uneven gaps and will not stick to the door in the heat.
- Floor threshold: a raised rubber hump glued to the slab under the door, so the bottom seal lands on it. It stops water where the driveway falls towards the garage.
How do I tell which garage door seal I have?
Open the door to about chest height, switch the opener off at the wall, and look at the end of the bottom rail. Pull a few centimetres of the old seal out of the channel and look at its cross-section: the beads or T-shaped edges that slide into the retainer, and the shape of the part that touches the floor. Measure the width of the retainer slots, the overall width of the door, and note the door maker's name, which is usually on a sticker inside a panel or on the rail. Take the offcut with you and match it by profile, not by the picture on the packet.
Are garage door rubber seals universal? No. Several door makers use their own retainer shapes, and a seal that fits one brand's rail will be loose or impossible to feed on another. Universal kits do exist, but they screw or stick to the face of the bottom rail rather than sliding into its channel. They work, but look added-on. If the retainer itself is cracked or bent, fix the rail first.
What is the best weather seal for each part of the door?
The best way to weather seal a garage door is from the bottom up, because the floor gap is the one that lets water in. Use the door maker's matching bottom seal where you can; if light still shows under it because the slab dips, a floor threshold fixes what a thicker seal cannot. For the sides of a sectional door with a smooth or lightly grooved panel, a rubber flap seal gives the tightest closure; on a deeply ribbed panel or a roller door, a brush seal copes with the profile better. In full afternoon sun, pick a quality EPDM rubber over a cheap PVC strip, which hardens and cracks sooner. If your home is in a bushfire-prone area, ask for seals suited to ember protection and check what your site's BAL rating actually requires.
How to replace a garage door bottom seal
The common case is a sectional door with a slide-in seal. Allow an hour and a helper.
- Raise the door to about waist height with the opener, then switch the opener off at the wall.
- Clamp a pair of locking pliers onto each vertical track just below the bottom rollers, so the door cannot drift down while you work.
- Pull the old seal out of the retainer from one end. If it has baked in place, a spray of silicone or soapy water along the channel helps it slide.
- Clean the channel with a rag and check it for cracks, dents or crushed ends. Straighten small kinks with pliers.
- Mist the new seal and the channel with soapy water or silicone, then feed the beads into the slots from one end while your helper pulls from the other.
- Trim it a little longer than the door, because rubber shrinks slightly as it settles. Crimp or pinch the retainer ends so it cannot creep out.
- Remove the clamps, switch the opener back on and close the door. The seal should compress evenly along the floor.
- Test the safety reverse before you walk away (see the warning below).
A new seal changes where the door stops
A fresh, fuller bottom seal or a new floor threshold means the door meets the floor earlier than the opener expects. Lay a small block of timber flat under the door and close it: the door must stop and reverse when it touches. If it pushes down hard or does not reverse, the opener's close limit and force need resetting before the door is used again.
If the door now stops short or bounces back open on its own, the opener has read the new seal as an obstruction. Our guide to resetting a garage door opener's limits covers the common process, and the troubleshooting page for a door that won't close covers the other usual causes.
Why garage door seals wear out faster in Perth
Sun is the main enemy. A west-facing door takes the full afternoon heat on its bottom edge, and the rubber hardens, shrinks and splits long before one on a shaded south-facing garage. Grit is next: sand trapped under the bottom seal wears it like sandpaper each time the door closes. Near the coast, salt stiffens the rubber and corrodes aluminium retainers. Signs yours is done: daylight under the door, cracks when you bend the rubber, flattened sections, and a line of dust or leaves just inside the door. A wipe with a damp cloth and a light coat of silicone once or twice a year keeps rubber supple for longer; the silicone routine in our garage door lubrication guide is safe on seals.
Can I install a garage door seal myself?
Usually, yes. Side and head seals only need a drill and a straight line, and a slide-in bottom seal is manageable with the steps above. Leave it to someone else when the retainer is damaged, when the door is out of square so no seal can close it, or when the opener needs resetting and you are not comfortable doing it. If you are in Perth and the gap is still there after a new seal, the door itself may be sagging or out of balance, and a garage door service is the sensible next step: we replace worn seals, adjust the door so it meets the floor evenly and retest the opener's safety reverse before we leave.
Seal kits specific to a door model are listed in its maker's documents, such as B&D's manual library, and WA Consumer Protection explains your rights if a fitted seal fails early.