How to Protect Outdoor Wooden Furniture in Winter

Why Winter Takes Its Toll on Outdoor Timber

British winters are a proper test of anything left outside. Driving rain, long damp spells and the freeze-thaw cycle all work away at timber. Water soaks into the grain, expands as it freezes overnight, and forces the fibres apart. Repeat that a few dozen times and you get cracked boards, opened joints, and grey, fuzzy surfaces where mould and algae have taken hold. Metal fixings suffer too, and a rusted bolt can stain the wood and loosen a chair that was rock-solid in September.

The good news is that an afternoon's work in autumn saves you a great deal of repair work — or replacement — in spring. The routine is straightforward: clean it, dry it, feed it, then store or cover it properly.

Start With a Thorough Clean

Dirt holds moisture against the surface, so cleaning is not cosmetic — it is part of the protection. Work on a dry, reasonably mild day so the timber has a chance to dry afterwards.

• Brush off leaves, cobwebs and grit with a stiff hand brush, paying attention to joints, slats and the undersides of tabletops.
• Wash with warm water and a little washing-up liquid, using a soft brush or cloth. Avoid a pressure washer, which drives water into the grain and lifts softer fibres.
• For green algae or black mould, use a diluted white vinegar solution or a proprietary fungicidal wash, then rinse well. Test on a hidden patch first, and never mix cleaning products.
• Rinse with clean water and wipe down rather than leaving puddles sitting on the surface.

If the furniture is painted or varnished and the coating is flaking, scrape and sand those areas now. Fresh coating will not adhere to a failing one.

Dry It Out and Check for Damage

Give the timber two or three dry days to dry naturally, raised off the ground on battens so air can move underneath. Damp wood will not absorb oil or stain properly, so this step matters more than it sounds.

While it dries, inspect it closely:

• Joints: wobble each chair and table. Loose joints should be re-glued and clamped before winter, not after.
• Fixings: replace rusty screws and bolts with stainless steel or galvanised equivalents.
• Splits and rot: small surface checks are normal. Soft, dark or crumbly patches are not — cut those out and treat or replace the section.
• End grain: legs, arm ends and board edges soak up water fastest, so note where they need extra attention.

Lightly sand any rough or raised areas with a medium grit, then wipe off the dust.

Feed and Seal the Timber

This is the step that actually keeps water out. Choose a finish to suit the wood and its existing coating.

• Oiled hardwood (teak, iroko, acacia): apply a dedicated teak or Danish oil in thin coats, wiping off the excess after twenty minutes. Two or three coats, with a day between each, gives proper protection.
• Bare softwood: a water-repellent wood preserver with UV protection works well and lets the grain show. Brush it on generously, especially on end grain.
• Painted furniture: sand, prime any bare patches, then apply a suitable exterior gloss or eggshell. Paint over oiled wood will not adhere — strip it back first.

Work in dry conditions above roughly 10°C, and follow the drying times on the tin. A coat on the underside and legs is worth as much as one on the top.

Store It Well, or Cover It Properly

If you have the space, a dry shed or garage is the best home for the winter. Stand pieces on battens rather than directly on concrete, which wicks moisture upwards, and avoid wedging everything tightly together — air needs to circulate. Take cushions, parasols and fabric slings indoors, where they will not go mouldy.

If the furniture has to stay outside, resist the temptation to throw a plastic tarpaulin over it. Non-breathable covers trap condensation underneath, which is worse than leaving the wood exposed. Instead:

• Use a breathable, water-resistant cover sized for the furniture, so it does not sit in puddles.
• Leave a gap at the bottom for airflow, and secure it against wind.
• Raise legs off paving with small blocks or feet caps.
• Position pieces away from dripping gutters and overhanging trees.

Keep an Eye on Things

A five-minute check once a month through the winter catches most problems early. Brush off fallen leaves after storms, tip standing water off covers, and look for any new mould or soft patches. If you spot mould, wipe it off with diluted vinegar before it stains. Come spring, a quick wash and a fresh coat of oil will have your furniture looking every bit as good as it did last summer — and it will last years longer for the trouble.