- Face-fix 26x117mm: £55–£65/m² boards. Most affordable profile.
- Secret fix grooved 26x117mm: £60–£72/m² boards + £3–£5/m² Brofix clips.
- Secret fix smooth 26x140mm: £65–£78/m² boards + Brofix clips.
- Secret fix brushed 26x140mm: £68–£85/m² boards + Brofix clips. Premium profile.
- Installed cost: Add £8–£15/m² subframe and fixings + £25–£45/m² labour.
- 20m² deck total installed: £1,760–£2,900 depending on profile and region.
- Zero maintenance for 25–40 years. No annual oiling. No replacement. No scaffolding maintenance costs.
ThermoWood decking costs more upfront than softwood — and significantly less over 20 years. The upfront premium of £55–£85 per m² for boards versus £18–£30 for pressure treated pine is the number most buyers focus on. The number that actually matters is the whole-life cost over the deck's service life: zero maintenance expenditure for 25–40 years versus annual oiling, potential replacement, and access costs for softwood. This guide gives you complete, accurate 2026 pricing for every ThermoWood decking profile — boards, Brofix clips, subframe, installation — and the honest whole-life cost comparison that shows why ThermoWood is cheaper than softwood for most homeowners within a decade of installation.
ThermoWood decking boards — thermally modified Scots pine with Durability Class 2 performance and zero maintenance for 25–40 years. Available in face-fix and three secret fix profiles from UK stock.
ThermoWood Decking — All Profiles Priced 2026
| Profile | Dimensions | Fix method | Boards/m² | + Brofix clips | + Subframe & fixings | + Labour | Installed/m² |
|---|---|---|---|---|---|---|---|
| Face Fix 26x117mm | 26×117mm | Face fix | £55–£65 | — | £8–£15 | £25–£45 | £88–£125 |
| Secret Fix Grooved 26x117mm | 26×117mm | Brofix hidden | £60–£72 | £3–£5 | £8–£15 | £25–£45 | £96–£137 |
| Secret Fix Smooth 26x140mm | 26×140mm | Brofix hidden | £65–£78 | £3–£5 | £8–£15 | £25–£45 | £101–£143 |
| Secret Fix Brushed 26x140mm | 26×140mm | Brofix hidden | £68–£85 | £3–£5 | £8–£15 | £25–£45 | £104–£150 |
All installed costs include C16 treated softwood joists at 400mm centres, perimeter frame, joist hangers, A4 stainless fixings, weed membrane, and professional installation. They exclude VAT (20% on residential labour), steps and balustrade, and groundworks. London and South East add 25–35% to labour cost.
Total Cost by Deck Size — 2026
| Deck size | Face fix installed | Secret fix grooved installed | Secret fix smooth installed | Secret fix brushed installed |
|---|---|---|---|---|
| Small — 10m² | £880–£1,250 | £960–£1,370 | £1,010–£1,430 | £1,040–£1,500 |
| Typical — 20m² | £1,760–£2,500 | £1,920–£2,740 | £2,020–£2,860 | £2,080–£3,000 |
| Large — 30m² | £2,640–£3,750 | £2,880–£4,110 | £3,030–£4,290 | £3,120–£4,500 |
| Wraparound — 50m² | £4,400–£6,250 | £4,800–£6,850 | £5,050–£7,150 | £5,200–£7,500 |
The Secret Fix Premium — What You Get for the Extra Cost
The most common question about ThermoWood decking cost is why the secret fix profiles cost more than the face-fix equivalent. The premium breaks down into three components:
- Board manufacturing premium (£5–£20/m²): The secret fix profiles — grooved, smooth, and brushed — require additional machining to create the groove that accepts the Brofix clip. The smooth and brushed profiles are also wider (26x140mm versus 26x117mm), which adds material cost
- Brofix clip cost (£3–£5/m²): The Brofix hidden decking fastener system clips engage in the board groove and fix to the joist with a single stainless screw. Approximately 5–7 clips per m² depending on joist spacing
- Installation time premium (included in labour): Secret fix installation is approximately 15–20% slower per m² than face-fix — each clip must be positioned and screwed before the next board is offered up. This is already reflected in the installed cost figures above
The result of this premium is a completely clean deck face — no visible screw heads at any point across the deck. For contemporary garden rooms, architect-designed outdoor spaces, and any project where the visual quality of the finished deck matters, the secret fix premium of £8–£25/m² over face-fix is almost universally considered worth paying.
Brofix Hidden Fasteners — Cost and How They Work
The Brofix hidden decking fastener system is the fixing method for all ThermoWood secret fix profiles. Each clip is a stainless steel bracket that slides into the groove on the board edge and is secured to the joist with a single A4 stainless screw. The next board's groove captures the protruding tab of the clip — locking it in place and holding the previous board down simultaneously. No fixings are visible on the deck face at any point.
Brofix clips cost approximately £3–£5 per m² of deck area at standard 400mm joist spacing. This is in addition to the board cost and the standard subframe materials. It is the only additional consumable required beyond standard deck construction materials — no special tools, no adhesive, no additional membrane.
ThermoWood vs Pressure Treated Softwood — Whole-Life Cost
The upfront cost comparison strongly favours softwood. The 20-year whole-life comparison favours ThermoWood significantly. The crossover point — where ThermoWood becomes cheaper in total — typically falls between year 8 and year 12 depending on deck size and maintenance access.
| Cost element | Pressure Treated Pine (20m²) | ThermoWood Face Fix (20m²) |
|---|---|---|
| Installation (year 0) | £1,020–£1,800 | £1,760–£2,500 |
| Annual oiling — years 1–15 | £900–£1,800 (£60–£120/yr) | £0 |
| Replacement at year 15 | £1,020–£1,800 | £0 (still performing) |
| Annual oiling — years 16–25 | £600–£1,200 (new deck) | £0 |
| 25-year total | £3,540–£6,600 | £1,760–£2,500 |
On a 20m² ground-level deck outside London, the upfront premium of ThermoWood face-fix over pressure treated softwood is approximately £740–£700. Annual oiling savings of £60–£120 per year mean ThermoWood recoups its premium within 6–12 years. For elevated decks where safe maintenance access requires equipment (£150–£400 per scaffolding visit), the crossover is within 2–5 years. Over 25 years, ThermoWood is approximately £1,800–£4,100 cheaper than maintained and replaced softwood on a 20m² deck.
Regional Price Variation UK 2026
ThermoWood decking board prices are consistent nationally — we supply from our Cambridgeshire depot at the same price regardless of delivery location. Labour varies significantly:
| Region | Installation labour/m² | vs Midlands baseline |
|---|---|---|
| London | £35–£55 | +25–35% |
| South East | £30–£48 | +15–25% |
| Midlands / East Anglia | £25–£38 | Baseline |
| North of England | £22–£35 | −5–10% |
| Scotland / Wales | £22–£36 | −5–10% |
ThermoWood vs Hardwood Decking — Cost Comparison
ThermoWood and hardwood decking are broadly comparable in installed cost at the premium end — the main cost difference is board price and service life. See our full ThermoWood vs hardwood decking comparison for the detailed head-to-head.
| Species | Boards/m² | Installed/m² | Service life | 25-yr whole-life cost |
|---|---|---|---|---|
| ThermoWood (face fix) | £55–£65 | £88–£125 | 25–40 yrs | £88–£125/m² |
| ThermoWood (secret fix) | £60–£85 | £96–£150 | 25–40 yrs | £96–£150/m² |
| Yellow Balau hardwood | £65–£90 | £98–£150 | 40–60 yrs | £98–£150/m² |
| Siberian Larch | £45–£70 | £78–£130 | 20–30 yrs | £78–£130/m² |
| Pressure Treated Pine | £18–£30 | £51–£90 | 10–15 yrs | £170–£280/m² (replacement) |
How much does ThermoWood decking cost in the UK?
£55–£85/m² for boards in 2026. Face-fix 26x117mm at £55–£65/m². Secret fix profiles £60–£85/m² plus Brofix clips at £3–£5/m². Total installed 20m² deck: £1,760–£2,900 including subframe, fixings, membrane and professional installation. Zero maintenance for 25–40 years.
Is ThermoWood decking more expensive than pressure treated softwood?
2–3x more expensive upfront — £55–£85/m² versus £18–£30/m² boards. But ThermoWood requires zero maintenance and no replacement for 25–40 years. Softwood needs annual oiling and replacement at 15 years. Over 25 years ThermoWood is approximately £1,800–£4,100 cheaper on a 20m² deck. The upfront premium is typically recovered within 8–12 years.
How much does ThermoWood secret fix decking cost?
Secret fix boards cost £60–£85/m² plus Brofix clips at £3–£5/m². Total installed cost £96–£150/m² — approximately £8–£25/m² more than face-fix. The premium gives you a completely clean deck face with no visible screw heads.
What is the cheapest ThermoWood decking profile?
The face-fix 26x117mm at £55–£65/m² boards — the most affordable ThermoWood profile. All profiles share identical durability (Class 2, 25–40 years, zero maintenance). The price difference reflects the manufacturing specification and fixing system, not performance.
Is ThermoWood decking worth the cost?
For any deck planned to last 15+ years — yes. The upfront premium over softwood is recovered within 8–12 years through zero maintenance costs. Over 25 years ThermoWood is significantly cheaper whole-life than maintained and replaced softwood. See our full ThermoWood decking worth it guide for the complete analysis.
ThermoWood Decking — UK Stock, All Profiles, Fast Delivery
We supply ThermoWood face-fix and all three secret fix profiles from UK stock. FSC and PEFC certified. Brofix clips available separately. Tell us your deck dimensions for a precise board quantity and full material list. Nationwide delivery 7–14 days.