uPVC Window Maintenance: A Winter Checklist for Windows and Doors

The first hard frost arrives, and the back door that shut with one hand in September now needs a shoulder against it before the handle will lift. Upstairs, a casement leaves a thin line of water along the sill every morning. Neither is a disaster, and most of the time neither means the product has failed. They are the small jobs that a bit of uPVC window maintenance heads off before winter properly sets in.

uPVC is about as low maintenance as windows and doors get, but low maintenance is not no maintenance. Below is the routine we recommend, taken from our own care and maintenance guide, in the order we would tackle it on a dry afternoon in November. It is written for homeowners, and for installers who get asked “is there anything I should be doing?” at handover.

Why the cold shows up problems

A Scottish winter tests a window in three ways at once: wind-driven rain, cold nights and long weeks with the house shut up. Drainage channels that quietly filled with leaves over autumn suddenly have real water to shift. Hinges and keeps that have not seen oil for a couple of years start to stiffen. And uPVC moves slightly with temperature, so a door that was set up perfectly in summer can feel tighter, or looser, after a cold snap.

You need no specialist kit: warm soapy water, a soft cloth, light machine oil and a 4mm Allen key cover nearly everything.

The winter uPVC window maintenance checklist

This applies to casement windows and tilt and turn windows alike.

1. Clear the drainage slots. Our windows and doors have a built-in drainage system, and it only works if the slots along the bottom of the frame are clear. Pick out leaves and grit, then pour a little water through to check it runs away outside. Take care not to pull the weather seals out of position while you do it, and if one lifts, press it straight back.
2. Wash the frames. Warm water with a little washing-up liquid (one without bleach) and a soft cloth is all a uPVC frame needs, wiped dry afterwards. We suggest every three months, or every month near a busy road or on the coast, where traffic film and salt spray build up faster. Go gently on woodgrain foils.
3. Clean the glass properly. Soap and water first to lift the grime, then a household glass cleaner and a soft cloth for the finish. Take rings off before you start, because jewellery is an easy way to scratch glass, and don’t reuse a cloth you have dropped on the ground.
4. Check the weather seals. Run a hand around each opening sash. The gaskets should sit evenly all the way round, with no gaps at the corners. A seal knocked out of its groove is a common cause of a winter draught, and often a two-minute fix.
5. Oil the hinges and locking points. Once a year, clean the dirt off the hinges, put a drop of light machine oil on each pivot point and wipe away the excess. Keep the sliding locking mechanism around the sash free of dirt and oil it too. On tilt and turn windows, a light spray or drop of oil at each lubrication point once a year keeps the gear running smoothly.
6. Look at the mastic. Check the silicone seal between the frame and the wall for cracks. If it has split, cut it out and run a new bead of silicone sealant.
7. Tighten what has worked loose. Check the fixing screws on handles and hinges. Where a window has adjustable locking cams, a small turn with a 4mm Allen key can pull the sash in more firmly against its seals. If you are not sure, leave that one to your installer.

Doors need a little extra attention

Doors take more of the weather than windows, so they have a few jobs of their own:

• Keeps and moving parts: clean and lightly grease the external moving parts and the frame keeps once a year.
• Hinges: oil the hinge pins annually, or every six months on an open-out door.
• Letterbox: a drop of oil on the springs of the inside and outside flaps once a year.
• Lock cylinder: leave it alone. Don’t try to lubricate the cylinder itself.
• Patio doors: keep the track and its drainage clear of grit, don’t lubricate the wheels, and oil the handle once a year.

One habit is worth passing on to every household. On a door with a multi-point lock, lift the handle to engage the locks each time the door is closed, then turn the key. It pulls the door in tight against its seals, which matters more on a wild January night than any draught excluder.

Good design does a lot of the work. Our uPVC doors are double rebated, so they have both an outer and an inner seal, and they are steel reinforced. Our composite doors add a triple seal frame and corrosion-proof, salt spray tested hardware with a 25 year hardware guarantee. Seals and hardware on these, and on our patio sliding doors, still last longest with this small amount of care.

What to keep away from uPVC

A lot of avoidable damage to uPVC frames comes from the cleaning cupboard rather than the weather. Avoid:

• Bleach, or washing-up liquids that contain it
• Solvents such as white spirit, cellulose thinners or nail varnish remover
• Aerosol sprays such as WD40 as a frame cleaner, and car dashboard wipes
• Acids, brick wash solutions and alkalis
• Abrasive creams, scouring pads and wire brushes
• Pressure washers, or a lot of pressure of any kind

Purpose-made uPVC cleaners are fine used sparingly, as too much can loosen silicone sealants.

When care is not enough

Maintenance keeps good windows working. It cannot rescue frames at the end of their life. If the sealed units have misted between the panes, a sash has dropped so far that it catches the frame, or rooms stay cold however tight the seals are, it is time to think about replacement. Our post on when double glazing needs replacing covers the warning signs, and if the problem is water on the inside of the glass, start with our guide to stopping condensation on windows. For help with heating costs and home upgrades, Home Energy Scotland is a good free starting point.

Scotia is a longstanding member of the Glass and Glazing Federation, and we assess any concern raised by a housebuilder or homeowner against its visual quality guidelines, which you will find next to our care guide. If you fit our products, that guide is worth leaving with the customer at handover, and the team at our Trade Centre in Kilmarnock can help when you are pricing up the replacements a winter check turns up.

Quick answers

How often should uPVC windows be cleaned?
Every three months as a rule, and monthly near busy roads or the coast.

Can I use WD40 on uPVC windows?
Not as a cleaner on the frames, because aerosol products can damage the surface finish. The hinges, handles and locking points need a light oil once a year, and a door’s lock cylinder should not be oiled at all.

Why is my uPVC door hard to lock in winter?
Often the door has moved slightly with the cold, or the keeps and locking points need cleaning and greasing. If it is still stiff after that, ask your installer to adjust it rather than forcing the handle.

If a window or door is past saving, or you are planning a replacement project, get in touch with our team or download our brochure to see the full range made in our own Ayrshire factories.