Rain, Wind and the Door That Keeps Its Cool: A Winter Patio Door MOT

November has a way of announcing itself. One week you are debating whether to wear a coat; the next, a named storm is flinging leaves at the glass and the patio door track has become a shallow paddling pool. This is the season when small maintenance jobs pay for themselves. The goal is simple: get the door through to March without water finding its way inside, without rollers seizing up and without a Sunday-night call to an emergency glazier.

Why autumn is the right time

By the time the first proper cold snap arrives, seals have usually had a summer of sun and grit. Tracks have collected grass, pollen and patio debris. A door that slid beautifully in July can feel heavy by Bonfire Night. A short check in late October or early November gives you time to order parts, book a service or replace a failed unit before the worst weather. It also gives you a baseline, so you can tell whether that new damp patch is a one-off or a pattern.

The five-minute track check

Start at the bottom. Open the door and look along the track. You are checking for leaves, grit, pet hair and that dark sludge that forms when dust meets rainwater. Use a vacuum with a brush attachment, a soft brush and a cloth. Avoid a pressure washer; it can force water past seals and into the frame. If there are drainage slots or weep holes, make sure they are clear. On sliding doors, check that water can run away rather than sitting in the channel.

While you are down there, look at the outside ground level. If the patio has been laid too high or a pot has been placed against the door, water may be directed towards the frame instead of away from it. A simple adjustment to drainage or a repositioned planter can make more difference than any sealant.

Seals: look, feel and listen

Run your hand along the seals. They should feel flexible, not brittle. Look for cracks, flattened sections, gaps at corners and black mould that has taken hold in the rubber. On sliding doors, check the brush seals and the interlock seals where the panels meet. On French and bifold doors, check the compression seals around the opening edge. If a seal has perished, replace it rather than trying to bulk it out with silicone.

A useful test is the paper test. Close the door on a strip of paper and try to pull it out. If it slides out with no resistance, the seal is not doing much. Do this in a few places around the door. It will not give you laboratory data, but it will tell you whether you have an obvious draught path.

Hinges, rollers and handles

Wet weather does not just bring water; it brings grit and temperature changes. Hinges can stiffen, rollers can seize and handles can become stiff. Clean the hardware, then lubricate sparingly with a silicone spray or a suitable door hardware lubricant. Avoid spraying oil all over the track and then wondering why dust sticks to it. A little, in the right place, is better than a lot everywhere.

If the door is dragging, do not force it. A sliding door that needs a shoulder to open is telling you something. The roller may need adjusting, the track may be worn, or the panel may have dropped. Bifold doors can need hinge adjustment as the seasons change. These are usually small jobs for someone who knows the system, but they become expensive if you ignore them until the panel jumps the track.

Condensation clues

Condensation is a useful diagnostic tool if you read it correctly. Mist on the room-side glass is usually about humidity and ventilation, especially in kitchens and rooms where washing is dried. Mist between the panes means the sealed unit has failed and needs replacing. Water pooling in the track after rain is a drainage issue. Damp patches on the floor or plaster near the door are a warning sign and should be investigated promptly.

Do not solve condensation by sealing up the trickle vents. That makes the air staler and can push moisture into colder corners of the room. If the door has vents, keep them open and check they are not blocked by curtains or blinds. If the room has no background ventilation, ask a professional about the best solution rather than taping over the problem.

Early warning signs of water ingress

Catch water ingress early and you usually avoid the expensive version. Look for dark marks on the frame, bubbling paint, swollen timber, soft plaster, a musty smell or water stains on the floor. Check the corners of the frame and the base of the door, where water often collects. If you have timber doors, pay particular attention to the bottom rail and any end grain.

Take photographs of anything that looks suspicious. If the problem turns out to be a failed seal or a blocked drainage path, you will have a useful record. If it becomes an insurance matter, a dated photo is worth having. Do not wait for a deep puddle to appear before you act.

A simple November-to-March routine

At the start of November, clean the tracks, check the drainage holes, inspect the seals and lubricate the moving parts. After any named storm, look for standing water, displaced seals or new draughts. Once a month, open and close the door fully, including any locking points, so nothing seizes. Before a cold snap, check that the door still closes squarely and that the lock engages without force. In February, do another seal and drainage check before the tail end of winter.

When to call someone

Call a professional if water is getting inside, if the glass unit has misted between the panes, if the door is difficult to lock, or if the frame has moved. A good installer will appreciate a clear description and a few photos. It is far better to book a repair in November than to be searching for emergency help in January with a towel at the door.

A patio door is a simple thing when it is working: a bit of glass, a frame and some seals. In winter, it is also the barrier between a warm room and a wet garden. Ten minutes of attention now is cheaper than a new floor later.