Composite decking vs timber: which is right for a UK garden?

Timber decking costs less to buy. That is true, and anyone who tells you otherwise is selling something. The question worth asking is what each one costs to own over the ten years you will actually have it, and what you will be doing on the first dry Saturday in April each of those years. This guide puts numbers on both, then gives the honest cases where timber still wins.

The short answer

For a deck you expect to keep for more than five years, composite is cheaper to own, safer for bare feet, and takes a fraction of the maintenance. For a deck on a fixed budget, a rental, or a short stay, softwood timber is a perfectly sensible answer as long as you accept the yearly upkeep. If real wood matters to you for its own sake, buy real wood.

Purchase cost: what a 15m² deck costs in materials

A 15m² deck is a common size, roughly 5m by 3m. The board cost below uses our composite boards at £25 per 3.6m length and £34 per 4.8m length, 150mm wide, and typical UK merchant prices for treated softwood decking at the time of writing. Subframe, fixings and labour are similar for both and are left out.

	Softwood timber	Composite
Boards for 15m² (with 5% cutting waste)	£280 to £420	£730 to £760
Hidden fixings	Not usually; face screws £20	Clips £16.50 per 100, about £50
Stain or oil at fitting	£40 to £60	None
Year one materials	£340 to £500	£780 to £810

So composite costs roughly £300 to £450 more on day one for a deck this size. That gap is real, and it is why the next section matters.

Ownership cost: ten years of maintenance

Timber needs cleaning, and it needs re-oiling or re-staining roughly once a year to stay sealed. Skip it for a couple of seasons and the boards start to grey, lift and split. Boards that have gone soft need replacing individually, which is fiddly work because the neighbouring boards are screwed down over the same joists.

Composite needs sweeping and an occasional wash. It does not need sealing, staining or oiling, because the colour goes through the board rather than sitting on top of it.

Over ten years	Softwood timber	Composite
Decking cleaner and stain or oil, yearly	£45 to £70 × 10 = £450 to £700	£0
Replacing rotten or split boards (typical 10 to 15% by year 7)	£60 to £90	£0
Weekends spent on it	One to two per year	An hour with a broom
Ten-year materials total, including purchase	£850 to £1,290	£780 to £810

By year six or seven the lines cross. Over ten years timber usually costs more in materials alone, before you count your time. If you would pay someone to do the staining, timber loses in year three.

Splinters, slips and bare feet

This is where composite tends to win outright for families. Timber splinters as it ages, particularly along cut ends and around fixings. Composite does not. Wet timber can also get genuinely slippery once algae takes hold in the grain, which in a British garden is most of the winter. Our boards are reversible, with a grooved face and a woodgrain face, and both are designed to keep grip when wet.

Appearance over time

Freshly stained timber looks superb. That look lasts one season. After that it depends entirely on whether the staining gets done, and the deck spends most of its life somewhere between "just done" and "overdue".

Composite lightens slightly over the first few months as the wood fibre settles, then holds its colour. Our colour guide explains what to expect from each of the eight finishes. The board you unwrap is a shade darker than the board you will have in six months, and after that it stays put. It will never look like real oak up close, because it is not, but it looks the same in year eight as it did in year one.

Where timber still wins

Three honest cases:

• Budget is the constraint. If composite puts the project out of reach, a maintained timber deck beats no deck. Spend the saving on a good subframe and a decent stain.
• You want real wood. Composite is convincing, and it is not oak or cedar. If the material itself matters to you, buy the material and commit to looking after it.
• It is temporary. A deck for a rental, a short stay, or a garden you will redesign in three years does not need a ten-year answer.

There is a fourth case people raise: very heavy loads such as a hot tub. Both materials handle it if the subframe is built for it. That is a joist question, not a board question.

What composite does not fix

Composite still needs a proper subframe, correct joist centres and expansion gaps. It expands and contracts with temperature like everything else, and it will still trap water if you lay it flat with no drainage. Our installation guide gives the figures our boards are made for: joist centres at no more than 350mm, 40mm of airflow under the frame, and end-to-end gaps of 3mm to 9mm depending on the temperature on the day you fit it.

The subframe can be timber, metal or composite. If you want the whole deck to be rot-proof rather than just the surface, our recycled plastic joists and battens do that job, and they matter most on the ground-contact members where timber goes first.

Environmental note

Our composite boards are made from recycled wood fibre and recycled plastic. Treated softwood is a renewable material but the treatment chemicals, the yearly stain and the shorter life count against it. Neither is a clean win; composite tends to come out ahead on a per-year-of-service basis because it does not need replacing at year ten to fifteen.

See it before you decide

Order free decking samples and leave them outside for a week. Look at them wet, look at them in the sun, and stand on them barefoot. That tells you more than any comparison table. If you also have a timber offcut to hand, leave it next to them and see which one you would rather stain next spring.

If you already know your deck size, the calculator gives a board count for either length. Standard delivery is 2 to 4 working days across mainland UK, kerbside, with next day available.