Composite decking lasts about 25 to 30 years, which is two to three times longer than a timber deck. Ours are commercial-grade board backed by a 15-year guarantee, and with nothing more than the odd wash they will see out decades without any sanding, oiling or replacing.

It is the question we get asked more than almost any other, and fair enough, because a deck is not a small spend and people want to know it will still be there in twenty years. The honest answer is that a good composite deck will outlast a timber one by miles, but how long you actually get depends on the board you buy, how it goes down, and whether you give it the odd clean. Here is the full picture.

How long does composite decking last compared to timber?

A composite deck lasts around 25 to 30 years. A timber deck, even a well-treated one, is usually looking tired and needing boards replaced within 10 to 15 years, and that is only if you have kept on top of the sanding, oiling and staining every single year. Composite skips all of that. It does not rot, it does not split, insects leave it alone, and it will not warp or splinter the way a softwood board does once the weather has had a few winters at it. You lose the annual upkeep and you roughly double the life. That is the whole reason people move across.

What shortens a composite deck’s life?

Composite is tough, but it is not bomb-proof, and most of the decks we have seen fail early went the same handful of ways. Worth knowing before you build:

• Water with nowhere to go. If the deck sits over damp ground with no airflow underneath, moisture and muck build up and the boards never get the chance to dry out. A subframe that lets air move and water drain away is half the battle.
• Never cleaning it. Leave leaves, dirt and standing water sitting on the surface for years and you will get a film of algae and green mould. It will not rot the board, but it looks tired and gets slippery. A wash once or twice a year keeps it right.
• A weak or badly spaced subframe. Joists set too far apart and the boards flex and feel bouncy, and the deck ages faster at the fixings. Get the joist centres right and the whole thing stays sturdy for decades.
• Cheap, thin-walled board. Lightweight, low-grade composite is the stuff that fades, sags and gives up early. A properly made, commercial-grade board costs a little more up front and lasts a lot longer.

Does composite decking fade over time?

A little, and anyone who tells you otherwise is having you on. Every decking material shifts colour under UK sun, composite included. What usually happens is the boards settle very slightly in the first few months and then hold steady for years after that. Capped board, like our Elite range, has a protective outer skin that holds its colour and shrugs off stains better over the long haul, so if maximum fade resistance matters to you, that is the one to look at. Our standard Woodsman board is uncapped, and for most gardens it weathers gently and evenly. Darker colours tend to show any change the least.

What does the 15-year guarantee actually mean?

It means we stand behind the board. Every board we sell carries a 15-year guarantee, so if one fails in that time through no fault of the way it was fitted, that is on us, not you. We would not put our name to that length of cover if we were not confident the boards go the distance. It is the difference between a supplier hoping a deck lasts and one willing to back it.

How do I get the most life out of my deck?

None of it is hard. Build it on a sound subframe with room for air to move and water to drain. Get your joist spacing right and leave the proper expansion gaps so the boards can move with the temperature, though ours are made hollow rather than full solid precisely to keep that movement to a minimum. Clear leaves and debris off now and then, and give it a wash with soapy water once or twice a year. Do that and there is no reason a composite deck will not give you a good 25 to 30 years looking after itself.

If you want to see how the boards hold up for yourself, order a free sample pack and leave it out in the weather for a week. And if you are weighing up one board against another, our composite decking boards are all commercial-grade and covered by that 15-year guarantee. Any questions on which suits your job, give us a call and we will talk it through.