How much is Composite Decking vs Wood?

Posted by Kerry Wilson on

How much is Composite Decking vs Wood?

We are often asked if composite deck really worth the extra cost? There's no hiding from the fact that the initial installation will cost more - WPC boards are more expensive to buy than timber. But is that the whole story? We took a look at the REAL costs involved.

To start with, we made some assumptions:

  • Both types of decking need the same type of base built
  • Both types of decking require fixings
  • Both types of decking will require similar tools - saw, screwdriver, tape measure etc.
  • Both types of decking will need a competent DIYer or a professional to install
  • We worked on a simple 3m x 5m deck (15 metres square)

First things first - how much will the boards cost? We compared B&Q GoodHome Madeira Brown Spruce Deck board (L)2.4m (W)120mm (T)24mm priced at £6.75 each with Direct Decking's Standard Grooved Composite Decking - Teak (L)3.6m (W)140mm (T)23mm which costs £22.80 per board. Colour and appearance is similar although the timber version has six grooves running down each board and the WPC version has 25 - so it looks smoother and will certainly feel better under bare feet.

The sizes are significantly different. One timber decking board gives 0.288 square metres of coverage - so you need 3.47 boards per square metre; that gives a price of £23.42 per metre squared. The same area in composite requires 1.98 boards which works out at £45.14/sqm. (If you're paying someone to install the deck on an hourly rate there could be a saving here - fewer boards mean fewer cuts and fewer fixings so should be quicker to install.) Either way, our 3m x 5m (15 metre square) deck will cost £351.34 in wood, and £677.16 in composite for the boards.

Once your timber deck is down it will need treating. Using Ronseal Matt Decking Wood Protector - a mid-priced option with good reviews - which recommends two coats on installation, one five litre container should be enough. It costs £29 and is water-based so, apart from the brushes or rollers you need to apply it, there aren't costs in solvents and it's not as toxic as some treatments. The WPC deck needs nothing extra doing to it - once it's down you can use it right away. Interestingly, the way the Ronseal product is described - 'Protect your decking from greying in the sun and rotting in the rain' - nicely highlights the main downside of using wooden decking boards.

Wooden decks need checking over regularly for signs of rot, warping, splitting, etc. Some sites suggest monthly checks (which feels like overkill) but to keep it looking it's best, you will need to check it at least once a year, fixing any rot or damage and reapplying the wood protector. Simply go over it with a wire brush, sweep away dust and debris and re-treat. A well-cared for wooden deck can last up to 15 years depending on how much sun and shade it's exposed to. A correctly installed WPC deck can last over 30 years...

So how does that all add up?

 Action Wood WPC
Cost of boards £351.34 £677.16
Cost of initial treatment £29.00 -
Cost of annual treatments over 15 years £217.50 -
Cost of replacement boards £351.34 -
Cost of initial treatment £29.00 -
Cost of annual treatments over 15 years £217.50 -
TOTAL COST £1195.68 £677.16

(We've assumed that the price of the wood and treatments will remain the same over 30 years - which is pretty unrealistic).

So there you have it. A timber deck is definitely NOT a cheaper option in the long term and you'll need to spend a whole lot more of your time on it too. Composite decking offers the most cost-effective solution. 

To work out how much your composite deck might cost try our handy decking calculator. It'll tell you exactly how many boards and fixings you need to fit your space. We've also provided tips on how to plan your deck to suit your lifestyle and your garden. And if you need more advice, our friendly team is on hand to take your calls Monday to Friday 9am to 4:30pm on 0800 6123 998.