How do you maintain wooden cladding indoors and outdoors?
Tips & maintenance · Maintenance
MaintenanceMaintaining wooden cladding
Indoors it is a matter of dust. Outdoors it is a matter of water — and of whether you want to let the wood turn grey or not.
- Indoors: dust and sun
- Outdoors: water and junctions
- Weathering is a choice
Indoors and outdoors are two different jobs
The same battens on a living-room wall and on a façade need a completely different maintenance rhythm.
Indoors, no water gets at it, which removes the main cause of decay. What remains is dust — which collects on the top of every batten and in every groove — and sunlight, which makes the wood darker or paler over the years. Both are cosmetic; neither is urgent.
Outdoors, it is all about water that cannot get away. As long as rain runs down the façade and the wood dries between showers, little happens. Problems arise where water sits or creeps behind the wood: at the bottom batten, around windows and doors, and behind a surface that cannot ventilate.
The big choice outdoors is whether you want to keep the colour. Untreated wood weathers to an even silver tone and stays structurally sound; that is not neglected maintenance but a valid choice. If you want to keep the original tone, that is a commitment that comes back every few years.
A wooden façade must be able to dry at the back. If there is no cavity or battening behind it, the back stays damp while the front dries — and the wood rots from the inside. No maintenance product solves that.
- Cleaning indoors
- dust, occasionally wipe with a slightly damp cloth
- Touching up indoors
- oil or wax every few years, if oiled
- Inspecting outdoors
- every year, in spring
- Weak spots outdoors
- bottom batten, junctions, end grain
- Weathering
- a choice, not a defect
- Keeping the colour
- stain or oil every two to five years
- Green growth
- soft brush and water, no pressure washer at full power
To be fair: if you want to keep a wooden façade in its original colour, you are signing up for a recurring job at height. Cleaning the whole façade, sanding lightly and treating it again every few years is not an afternoon's work, and on an upper storey you will need scaffolding or a cherry picker. Letting it weather is not laziness — it is often the wisest choice.
What an interior wall needs
Dusting
With a feather duster or the brush nozzle of the vacuum cleaner, in the direction of the battens. On a slatted wall, dust collects on every top edge, and you notice it mostly in raking light.
Wiping with a damp cloth
Now and then with a well wrung-out cloth and, if needed, a drop of mild soap. Never work wet on untreated wood: it leaves marks.
Touching up oiled wood
An oiled wall needs a thin new coat every few years. The advantage is that you can touch up locally without a visible transition.
Lacquered wood
Needs almost nothing, but cannot be touched up locally when damaged. A scratch stays visible until you redo the whole surface.
Sunlight
Wood behind a large window changes colour faster, and under a painting or a cabinet the old tone remains. Move large objects now and then if you want to avoid that.
Moisture in a bathroom or kitchen
Make sure there is ventilation and finish the wood with a coating that keeps out moisture. Untreated wood in a shower area will stain and swell.
In pictures · What to look at outdoors
Schematic drawing.
What to look at outdoors
| Spot | What you are looking for | Why there |
|---|---|---|
| Bottom batten | discolouration, soft spots | water splashing up from the ground or the terrace |
| End grain | open fibres, dark edges | end grain soaks up water much faster |
| Around windows and doors | open joints, sealant that has come loose | this is where water gets behind the wood |
| Under a roof edge | different colour | sheltered wood weathers more slowly; an uneven look is normal |
| North side | green growth | stays damp longer, less sun |
| Back | ventilation gap | without a cavity the wood cannot dry |
- CleanSoft brush, water and, if needed, a cleaner for exterior wood. A pressure washer is fine, but on low pressure and at a distance — otherwise you blast away the soft fibres.
- Let it dryA few dry days. Any treatment on damp wood traps the water.
- AssessProbe the suspect spots with a screwdriver. Soft wood means replacing, not painting over.
- Sand lightlyOnly where the old coating is rough or loose. On weathered wood you want to treat again: first down to sound fibre.
- TreatStain or oil in two thin coats, and the end grain twice. Do not work in full sun.
Let it weather or keep the colour?
Do nothing
After one to three years the wood moves towards an even silver-grey tone.
- No recurring job
- Structurally nothing changes
- It looks patchy for the first few years
- Sheltered parts weather more slowly: uneven look
- Still inspect for decay every year
Stain or oil
The original or chosen tone is kept.
- Redo every two to five years
- A considerable job at height
- Stain gives the most colour stability
- Touching up can usually be done locally
- Waiting until the coating has failed means sanding everything back
Frequently asked questions about maintaining cladding
How often should I treat a wooden façade?
If you want to keep the colour, every two to five years, depending on how exposed the façade is. If you let it weather, you need do nothing except inspect it every year.
Is weathering harmful?
No. Weathering is superficial UV damage to the outermost fibres and says nothing about the strength of the wood beneath.
Can I use a pressure washer?
On low pressure and at a distance. At full power you blast away the soft fibres between the growth rings, which makes the surface rough and means it actually holds dirt faster.
Why is my façade rotting even though it has been treated?
Probably the back cannot dry. Without a ventilation gap behind the cladding, the wood stays damp on the inside, and no product helps against that.
How do I remove green growth?
With a soft brush, water and possibly a cleaner for exterior wood. Then let it dry thoroughly before you treat anything.
How do I maintain a slatted wall indoors?
Dust in the direction of the battens and wipe now and then with a well wrung-out cloth. If the wall is oiled, touch it up lightly every few years.
Putting up a wall?
How to build a wooden feature wall and which pattern suits which room is covered separately.
Have a question about your project? Just ask — we're happy to help.
Photos via Wikimedia Commons: Neuschönau, Bavaria — Takmocsekretovanej!, CC0 · Nørre Vorupør, Denmark — W.carter, CC0
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