Timber window maintenance comes down to four jobs: wash the frames twice a year, check the sills and joints each spring, recoat the outside every few years, and fix small problems before water gets in. Done regularly, it takes a few hours a year. Neglected, it costs a new window.
We manufacture bespoke timber windows and doors, and the question we hear most from buyers is how much looking after they need. The honest answer is less than people fear, but not none. Natural wood moves with the seasons, and it isn’t indestructible. This guide explains what window joinery needs, how to do most of it yourself, and when to call in a joiner. It applies to modern timber and traditional timber windows alike, from Georgian and Edwardian period properties to new homes.
Multi-coat factory finish
Engineered pine, meranti or oak
Any RAL or Farrow & Ball colour
Around 20 working days
From £449 + VAT
In this guide
What You’ll Discover in This Article
- How to clean timber windows without damaging the finish
- What to look for when you check the condition of the window
- When and how to recoat, and which coatings to use
- How rotten timber is repaired, and when it’s time to replace
- A simple year-round maintenance calendar
01 · Why it matters
Why Timber Window Maintenance Matters
A wooden window fails for one reason: water gets into the wood and stays there.
Moisture Is the Real Enemy
Rot fungi only grow when wood stays damp, roughly above 20% moisture content, for long periods. A sound paint film, a sloped sill and tight joints keep the timber dry. Once the coating cracks or a joint opens, rain soaks in and the decay starts out of sight.
What Regular Maintenance Buys You
A 2013 Heriot-Watt University study for the British Woodworking Federation put factory-finished timber windows at 56 to 65 years of service life, provided they’re maintained. That’s a long time. Routine care is what gets you there, and it costs far less than a new window. Unlike uPVC windows, wood windows can be repaired again and again.
02 · Cleaning
Cleaning Timber Windows the Right Way
Cleaning timber is the easiest job on the list, and it does more than make the windows look good.
How Often to Clean
Twice a year is enough for most homes, usually spring and autumn. Windows near a busy road or the coast collect grime and salt faster, so clean those more often. Dirt and debris hold moisture against wooden frames and shorten the life of the paint.
What to Use When Cleaning Timber
Use warm water, a mild washing-up liquid and a soft cloth or sponge. Wipe the surface, rinse with clean water and dry it. Avoid abrasive pads, strong solvents and pressure washers, which strip the finish and force water into the joints. Any ordinary glass cleaner is fine for the pane, as long as it isn’t left to run onto the frame.
Don’t Forget the Hidden Parts
Clear the drainage slots and the grooves where an opening casement or sash closes. Brush out the corners and edges, where dust and leaves collect. Your autumn maintenance checklist goes through these steps one window at a time.
03 · Inspection
Checking the Condition of the Window
A quick check each spring helps you spot any potential problem while it’s still small.
Start With the Window Frame and Sill
Work from the bottom up. The sill and the bottom of each wooden window frame take the most rain, so decay usually starts there. Look at the joints, where the bottom rail meets the stiles, and at the putty or glazing beads around the glass.
Signs of Timber Rot
Press a screwdriver into suspect areas. Sound wood resists. Damp wood that’s soft, spongy or crumbles away is decaying. Other warning signs include flaking paint in one spot, dark staining, cracks in the corners and a musty smell.
Draughts, Rattles and Sticking
A window that rattles or lets in cold air usually has a worn draught seal or loose beads. One that sticks may be swollen, over-painted or out of square. Our guide to window seals for wooden windows explains which strip suits which window.
04 · Repainting
Repainting and Protective Coatings
The finish protects the timber. Keep it intact and the window stays dry.
How Often to Recoat
As a rough guide, a good factory paint finish needs its first recoat after about six to eight years on a sheltered wall, sooner on a south- or west-facing one. Translucent stains and oils need attention more often, typically every three to five years. Don’t wait for the paint to peel; recoat as soon as the surface looks chalky or thin. It’s important to maintain the film before bare wood shows.
Preparing the Timber and Old Paint
Most of the result comes from preparation. Wash the timber frames, let them dry, then sand lightly with 120-grit sandpaper to key the surface without tearing the wood fibres. If you use a sander, keep it moving. Scrape off loose old layers of paint back to sound wood, and treat any bare timber with a suitable primer. If your home was built before the 1960s, the old paint may contain lead, so test it before you sand.
Choosing a Coating for Wood Windows
Use a microporous exterior paint or stain suitable for timber windows. Microporous finishes let moisture escape from the wood while keeping rain out. Old-fashioned hard gloss paint or varnish tends to crack as the wood moves. Stick to the same system that’s already on the window where you can, because some paints don’t bond well over others. Every window we make leaves the workshop with a multi-coat factory finish, so a light recoat in the same colour is usually all it needs.
Application and Drying Time
You’ll get the best results on a dry, mild day. Most exterior paints need at least 8 to 10°C and no rain for several hours, so check the tin. Apply thin coats with a good brush, working along the grain, and lap the paint about 1 mm onto the glass to close the gap at the edge. Leave enough time between coats, and leave opening lights slightly open while they dry so they don’t stick shut.
05 · Repairs
Repairing Timber Rot and Damaged Frames: DIY or Joinery Specialist?
Small fixes are within reach of a competent DIYer. Larger ones are a job for a joiner.
Small Repairs to Wooden Windows
Cut out soft wood back to sound timber, then treat the area with a wood hardener. Fill it with a two-part exterior wood filler, shape it to the moulding, rub it smooth and paint over it. A good filler patch can last years.
Splicing in New Timber
Where decay has gone deeper, a joiner can cut out the damaged section and splice in new timber, glued and pinned. This is the standard way of repairing timber sills and the bottoms of frames. It keeps most of the original window and costs far less than starting again.
Repair or Replace?
Historic England’s guidance on traditional windows puts repair first, and for good reason: most historic windows can be saved. Replacement makes sense when decay runs through several joints, the frame has distorted, or the cost of the work approaches the cost of a new window. In a listed building, you’ll need consent before you replace anything.
06 · Hardware
Caring for Sash Windows, Casement Windows and Hardware
Moving parts need a little attention too.
Sash Window Cords and Pulleys
On a timber sash window with cords and weights, the cords eventually fray and the pulleys stiffen. Rub candle wax or a dry lubricant on the sides of the sashes so they slide freely, and replace cords at the first sign of wear. A sash window specialist can re-cord a window in a few hours.
Casement Hinges and Stays
Oil the pivots and friction stays once a year with a light machine oil, and wipe away the excess. Check that the screws are tight, because a dropped casement rubs and opens up the joints.
Locks and Ironmongery
Lubricate locks and espagnolette mechanisms once a year. Brass fittings can be cleaned with a soft cloth, but keep metal polish off the paint.
07 · Calendar
A Year-Round Window Maintenance Calendar
Here’s a simple routine that keeps most windows in good order. The same routine suits a timber front door.
| When | Job | Time per window |
|---|---|---|
| Spring | Wash frames and glass, check sills and joints for soft spots | 15 to 20 minutes |
| Spring | Clear drainage slots, check weatherstrips and putty | 5 minutes |
| Summer | Touch up chips and bare spots in dry weather | 10 minutes |
| Summer, every few years | Full recoat of exterior faces | 2 to 3 hours |
| Autumn | Wash again, oil stays, pivots and locks | 15 minutes |
| Winter | Wipe condensation from the glass and sills each morning | 1 minute |
If you’re choosing new windows, our weather-resistant timber windows are designed to keep water out and this list short. Fitting is arranged separately with your builder, joiner or a FENSA-registered installer.
Frequently Asked Questions
How often do timber windows need repainting?
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A good factory paint finish usually needs its first recoat after about six to eight years, sooner on exposed walls. Stains and oils need recoating more often, typically every three to five years.
Can rotten window frames be repaired?
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Usually, yes. Small areas can be cut out and filled. Deeper decay in a sill or the bottom of a frame can be cut out and spliced with new timber by a joiner.
What should I clean wooden windows with?
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Warm water, a mild detergent and a soft cloth. Avoid abrasive pads, strong solvents and pressure washers.
Are timber windows high maintenance?
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Not really. A clean twice a year, an annual check and a recoat every few years is enough for most homes. The work is regular rather than heavy.
Do you repair or fit windows?
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No. We’re a supply-only manufacturer: we make new timber windows and deliver them finished anywhere in the UK. Repairs and fitting are done by a joiner, sash specialist or FENSA-registered installer.
Summary
Conclusion: Repair Instead of Replacing
Timber windows reward a little regular attention. Keep them clean, keep the paint sound, and deal with soft spots early, and they’ll last for decades. Most problems can be put right, and repairing wooden windows is almost always better value than replacing them. It’s also the best way to preserve your home’s character.
When a window really is beyond saving, contact us with sizes and photographs. We’ll make a new one to match.
Our Best-Selling Timber Windows:
