Timber Decking Installation Cost UK: Softwood and Hardwood Prices

Our indicative range for timber decking installation is £1,500–£4,500. It assumes a domestic deck built at or near ground level, with the structure, boards, fixings, a step or two and the edge finish included. Pressure-treated softwood sits towards the lower end; hardwood, shaped edges and more elaborate steps move the price up.

A timber deck is really two specifications. There are the boards you see and walk on, and there is the structural timber underneath that carries them. Each has its own grade, treatment and cost, and a quote that describes only the boards is leaving out half of what you are paying for.

What a timber deck costs at each size

Two optional extras appear on our free quotes page as separate allowances: a short, simple timber step flight at £150–£500, and a basic timber balustrade at £40–£120 per linear metre. Only add them if the quote does not already include that work. A deck raised well above the ground is a different job; our raised decking cost guide covers it.

Where the money goes

Structural timber

Joists and bearers need to be sized for the spans involved and treated for the conditions they will sit in. The Timber Decking and Cladding Association recommends Use Class 4 treatment for softwood structural supports, even when they are above ground; see its advice on deck joists. Pressure treatment protects against decay but does not make timber stronger, so both qualities need specifying. Better-graded, properly treated framing costs more than generic timber, and it is the part of the deck you can least afford to skimp on.

Board species

Treated softwood boards are the usual starting point. Hardwoods cost more to buy and often take longer to fit: dense boards may need pre-drilling, and fixings must suit the timber. Modified timbers sit somewhere between the two. The choice changes how the deck looks as it weathers, as well as its price.

Ground preparation

Clearing turf, levelling, laying a weed-control membrane where it suits and setting supports all take time before any boards go down. Ground that is soft, wet or full of roots needs more work. The finished height also has to sit correctly against the house, below the damp-proof course and clear of air bricks, which can limit how the frame is built.

Shape, edges and steps

Straight-sided rectangles are the cheapest to build. Shaped corners, curves, a fascia board round the edge and steps all add cutting and framing. Every cut end of treated timber should be re-treated on site, which is a small cost but easily forgotten.

The first finish

Whether the first coat of oil or stain is included varies from quote to quote. Freshly treated timber may need time to dry before a finish will take, so a coating visit can be weeks after the build. Ask whether that visit is included or priced separately, and if you plan to do it yourself, ask when the wood will be ready.

Budgeting for the years after

A timber deck's cost does not stop on the day it is finished. Many owners clean and re-finish every so often, depending on exposure and the product used, and occasionally swap a damaged board. That ongoing cost is one of the main differences from composite; our composite vs timber decking guide sets the two side by side, and the composite decking fitted price guide shows what composite costs to install.

For a quick budget before anyone visits, use the decking cost calculator. To get prices for your own garden, describe the deck you want and up to four local installers may respond.