Looking after a composite deck: the real (and short) calendar
Cleaning, grease marks, green deposits, sand, rust stains: how to look after a composite wood deck in Morocco. The yearly calendar and the products to avoid.
This is the argument that decides most of our customers, so it is worth being precise: looking after a composite deck takes two half-days a year. No oil, no sanding, no stain. Here is exactly what to do, when, and above all what not to do.
The yearly calendar
In spring — the deep clean
Once a year, before the season of use.
- Sweep or blow off the sand, leaves and debris lodged in the grooves.
- Wet the deck with clean water.
- Wash with hot soapy water — black soap or washing-up liquid — using a soft-bristled brush, scrubbing along the grooves.
- Rinse thoroughly.
That is all. Allow two hours for 40 m².
In autumn — the maintenance clean
The same routine, in a lighter version. The aim is mainly to clear what has built up over the summer: sand, sun cream, plant debris.
All year round — the groove habit
The grooves are what give grip, and what trap debris. A regular sweep along them is enough to avoid 90% of clogging and green-deposit problems.
Common marks and how to treat them
| Mark | Treatment |
|---|---|
| Grease, sun cream | Hot water + degreasing washing-up liquid, soft brush |
| Wine, fruit juice | Soapy water immediately; bicarbonate paste if dried on |
| Green deposit, moss | Mild anti-moss cleaner, thorough rinse, then treat the cause |
| Rust marks | A specific cleaner with no strong acid; change the offending fixing |
| Sand and dust | Brush or blow along the grooves |
| Barbecue marks | Household degreaser, left a few minutes, then brushed |
The general rule: act fast. A fresh mark comes off with soapy water; the same mark after three weeks of sun takes far more effort.
What you must not do
Applying a decking oil or stain. Composite does not absorb. The product stays on the surface, forms a film that flakes off within a few months and attracts dust. It is the classic mistake of owners coming from exotic hardwood and repeating their habits.
Using a rotary nozzle on a pressure washer. It erodes the surface and creates a permanently fuzzy look. If you use one: pressure under 100 bar, flat-jet nozzle, 30 cm minimum distance, and always along the grooves.
Using neat bleach. It can lighten the colour locally and leave a permanently visible pale patch.
Scrubbing with a wire brush or an abrasive pad. You scratch the surface and create areas that will clog faster than the rest.
Leaving unprotected metal furniture on it. An iron table leg leaves a rust mark in the grooves. Felt or plastic pads on every foot.
Green deposits: treat the cause, not just the symptom
If an area of your deck goes green every year, an anti-moss cleaner will clean it — and it will go green again the following year.
The problem is not the material, it is water that is not draining. Three possible causes:
- No fall. A deck laid dead level holds water in the grooves. The 1% fall is set during installation and cannot be added afterwards.
- Blocked ventilation. Sand, gravel or vegetation has filled in the void under the joists. Clear it out.
- Permanently shaded area. Under a tree or against a north wall, evaporation is slow. Sweep that area more often; it is the only answer.
Our guide to installing a composite deck sets out the fall and ventilation rules that avoid the problem from the start.
How the shade changes: what is normal
Over the first three to six months, your deck will shift very slightly. The pigments settle under UV. The change is uniform across the whole exposed surface and then stops.
Do not confuse this with the greying of natural timber: that is continuous, it worsens year after year, and it is corrected by sanding. The change in composite is a one-off settling.
One practical point: if you add boards two years later, they will be slightly brighter than the older ones for a few months, then fall into line. Order a few spare boards with the original delivery if that difference would bother you.
Replacing a damaged board
This is one of the concrete advantages of composite: the repair is local.
If a board is deeply scratched or irreversibly marked, you unscrew it and replace it. With fixing clips, the job takes a few minutes. With face screws, a little longer.
And if your boards are double-sided — which is the case across our whole decking range — you can often simply turn the board over: the hidden face is untouched.
In short
Two cleans a year with soapy water and a soft brush. A regular sweep of the grooves. No treatment products. Pads under the furniture.
That is all a composite deck asks for — and it is exactly why people choose it.
