Timber decking in the UK

What wood is used for decking?

Decking timber in the UK is either softwood or hardwood. Softwood boards are pressure-treated so they survive outdoors, and hardwood boards cost more, as the price table below shows. Wickes sells a standard treated board at 25 by 120 mm and a “Pro” board at 27 by 144 mm, and says the standard board is pressure treated to use class 3, which is the grade for timber outdoors but not in ground contact.

We couldn’t find species-by-species lifespans for larch, Douglas fir, thermowood or tropical hardwoods from a UK trade body, so we don’t quote any. If a merchant gives you one, ask where it comes from.

How long does timber decking last?

The Wood Protection Association’s technical note says 15 years is the default service life for deck boards unless you specify 30, and BS 8417 sets the treatment needed to reach 15, 30 or 60 years. A UK supplier of anti-slip softwood decking treated to UC3 and UC4 gives 15 years for its pine. Wickes’ standard board has a five year anti-rot guarantee, and Wickes tells buyers to recoat all sides with deck seal, oil or stain.

The frame often fails before the boards. In one UK build, the frame was the dearest part of the deck, not the boards: the builder spent about £751 on the subframe and about £563 on boards for 23.5 m². That figure is as he said it on video in 2024, not a quote. Treat every cut end with preservative as you go: another UK builder points out that the factory treatment only soaks in a short way, so cut ends are unprotected.

What does timber decking cost per m²?

Those are MyJobQuote figures from October 2026 for an average 30 m² job, with no VAT status given. BestBuilders’ 2026 guide gives a supply and build range of £80 to £140 per m² for softwood and £140 to £220 for hardwood on level ground with a standard frame. Cladco puts timber boards alone at about £22 per m², excluding the frame, fixings and groundworks.

Wickes boards are £7 to £25 each. The 2.4 m standard board is £8, which is about £3.33 per metre.

What are the best decking boards for a garden?

For a garden on a budget, treated softwood. For a long life with less treatment, hardwood. If you want to stop oiling altogether, composite is the other option, which we compare on the composite decking page.

The decision comes down to upkeep. A deck of treated pine needs cleaning about twice a year and a fresh coat of oil, sealer or stain when the finish wears. One UK builder’s timber deck was fine after a year, with moss only where pots and a shed sat, so move planters and give the boards a coat of oil when they need it.

Grooved or smooth: which way up?

Check the maker first. Some timber boards are reversible and some aren’t, and boards with raised grippy sections are not. A UK DIYer who tested his own deck laid it smooth side up because leaves and algae collect in the grooves and oiling is easier on a flat face. He adds that most people in the UK pick grooves up, and that if the maker’s print is on the smooth face, that’s a hint the smooth side goes down. It’s his opinion, not a test.

How do you clean wooden decking?

Clear moss and leaves first, then pick the method for your boards.

• With a pressure washer, Wickes suggests 1,000 to 2,000 psi on a medium setting with the nozzle at least 6 inches away.
• Without one, use washing powder on wet boards, leave it about 30 minutes, scrub across the grain, then rinse along the grain. A UK gardener who avoids a pressure washer on oak says it can open the grain, which then holds more dirt and moss.
• For algae, Wickes suggests oxygen bleach at 1 to 5 with water for about 20 minutes. Another UK demonstrator leaves diluted bleach 10 to 15 minutes, rinses with a hose on a gentle setting and wears gloves. Both apply to timber, never to composite.
• A product such as Ronseal Decking Cleaner is brushed on, scrubbed, left 15 to 20 minutes and rinsed. Its page doesn’t give coverage per litre, so check the tin.

Let boards dry for at least 24 hours before painting or staining.

How do you make wooden decking less slippery?

Algae and wet leaves are the usual cause, so sweep at least once a year and clean the deck in early spring, before the main season. Some UK suppliers sell anti-slip softwood boards, but we haven’t sourced a test result for those, or for anti-slip strips or coatings, so we won’t name one.