Cost guide
How much does composite decking cost?
£110 per square metre installed is the 2026 figure for solid capped composite and £65 for hollow uncapped. Twenty five square metres comes to £1,650 to £2,750 depending which board is specified, with contractors charging £200 to £250 a day for the fitting.
Typical prices
Ranges, not quotes. A quote depends on your room.
| Work | Typical UK price |
|---|---|
| Hollow core board, per square metre supplied | £35 to £55 |
| Solid core board, per square metre supplied | £60 to £80 |
| Installed rate, composite, per square metre | £65 to £110 |
| 15 square metre deck, capped board | £1,300 to £1,650 |
| 25 square metre deck, capped board | £2,150 to £2,750 |
| 40 square metre deck, capped board | £3,400 to £4,400 |
Joist centres are the hidden cost in a composite quotation. A frame priced at 400mm spacing undercuts one at 300mm, fails the fitting instructions, and takes the warranty down with it.
What moves the price
- Board construction, hollow at £35 per square metre supplied against solid capped at £80.
- Capping, worth £20 to £25 per square metre over an uncapped equivalent.
- Joist centres, because 300mm spacing needs roughly a third more sub-frame timber.
- Fascia boards, trims and clips, which mount up on a deck with several exposed edges.
- Region, with London and the South East at the upper end of published rates.
Who quotes for it
Questions about composite decking
Can composite boards go on an old timber sub-frame?
Only after checking the joist spacing and the condition of every joist. Composite mostly needs 300mm centres, while older softwood frames were commonly built at 400mm, so extra joists have to go in. Timber soft at the bearing points gets replaced before boards go down.
What is the difference between capped and uncapped composite?
Capped boards have a bonded polymer shell on the outside resisting stains, fading and moisture. Uncapped boards share the same core, cost £20 to £25 less per square metre, and weather noticeably faster. Solid capped boards are the heaviest and carry the longest warranties.