Decking Cost Calculator
A realistic breakdown of timber costs, composite upgrades, and carpenter day rates to help you budget accurately for your new garden deck.
Decking Requirements
Dimensions (Metres)
Average UK garden deck is around 15m².
Why softwood?
Cheap initially, but factor in the £50+ you'll spend every spring on decking oil and the weekend you'll lose scrubbing it.
Cost Breakdown
A Guide to Garden Decking
Decking is one of the most popular ways to create a level, usable seating area in a sloping or uneven UK garden. It is generally faster to build than a stone patio (which requires immense groundworks and wet mortar) and creates a softer, warmer aesthetic that bridges the gap between the house and the lawn.
The Hidden Cost: The Subframe
Many homeowners look at the price of decking boards in B&Q (e.g., £20 a square metre) and assume an area of 10 square metres will cost £200. This ignores the most important and expensive part of the deck: the structure underneath.
The boards you stand on are purely cosmetic. You are actually paying a carpenter to build a highly robust scaffolding of thick treated timber joists that floats exactly level above the dirt. This subframe requires structural screws, joist hangers, concrete pads, and heavy 6x2 inch lumber. Often, the frame costs just as much as the top boards.
Comparing Materials
Softwood (Treated Pine)
The default option for 80% of UK gardens. The timber is pressure treated with preservatives (giving it a slight green tint initially) to prevent immediate rot.
Pros: Very cheap, easy for the builder to cut, offers a natural look.
Cons: High maintenance. If you don't scrub and paint it with decking oil every year, the British winter will turn it slippery, grey, and eventually rotten within 10 years.
Hardwood (Oak, Balau, Teak)
Sourced from slow-growing trees.
Pros: Absolutely beautiful tight grain, incredibly strong, naturally resists rot much better than pine.
Cons: Extremely expensive. The wood is so hard that the carpenter must pre-drill every single screw hole, adding significant labour time to your bill.
Composite Decking
Made from a baked mixture of recycled wood fibres and plastic polymers.
Pros: The holy grail of low maintenance. It never rots, never splinters, and never needs painting. It just stays looking perfect year after year.
Cons: The most expensive upfront option (though it pays for itself by saving you 15 years of buying wood oil). Can get quite hot on bare feet in direct mid-summer sun.