- Lunawood ThermoWood is Finnish thermally modified timber — one of the world's most specified ThermoWood brands, widely used by UK architects on contemporary residential and commercial facades.
- Available in the UK in triple shadow gap, double shadow gap, tongue and groove, and rainscreen profiles — all from stock with nationwide delivery in 7–14 days.
- Lunawood carries a BRE-accredited 30-year service life for external cladding and is classified as Durability Class 2 (BS EN 350).
- No chemical treatment required — the thermal modification process provides decay resistance without preservatives.
- The triple shadow gap profile in 26x92mm and 32x140mm is the most widely specified Lunawood product in the UK — detailed specifications and costs in this guide.
Lunawood ThermoWood is one of the most recognised thermally modified timber brands in the UK architecture and specification market. Produced in Finland by Oy Lunawood Ltd — one of the world's leading ThermoWood manufacturers — Lunawood cladding combines the natural appearance of Nordic pine and spruce with permanently improved stability, durability, and moisture resistance achieved entirely through heat and steam, without chemical treatment.
This guide covers everything UK buyers, architects, and specifiers need to know about Lunawood ThermoWood cladding — what it is, how it performs, which profiles are available, how it compares to other ThermoWood products, and where to buy it in the UK from stock. We stock and supply Lunawood ThermoWood profiles across the UK with nationwide delivery in 7–14 days, backed by FSC and PEFC certification.
What Is Lunawood ThermoWood?
Lunawood ThermoWood close-up — the uniform honey-brown tone, tight grain, and resin-free surface are the result of thermal modification using only heat and steam.
Lunawood ThermoWood is thermally modified Nordic pine (Pinus sylvestris) and spruce (Picea abies) produced by Oy Lunawood Ltd in Finland. The timber is heated to 185–215°C in a closed kiln using steam, without oxygen and without chemicals. This process permanently alters the cell structure of the wood — reducing moisture absorption by up to 50%, improving dimensional stability, eliminating resins, and increasing natural resistance to biological decay. The result is timber rated as Durability Class 2 (BS EN 350) with a BRE-accredited 30-year service life for exterior cladding applications.
Lunawood was one of the founding members of the International ThermoWood Association and remains one of the most technically advanced ThermoWood producers globally. Their production process uses a continuous kiln system — rather than the batch processes used by some competitors — which produces more consistent results across each timber batch in terms of modification depth, colour uniformity, and mechanical properties.
In the UK, Lunawood ThermoWood has become particularly well known among architects and specification professionals for two reasons. First, its consistent quality — architects who specify Lunawood know what they will get in terms of colour, stability, and surface finish. Second, its range of precise, well-engineered profiles — particularly the triple shadow gap, which has become one of the most recognisable contemporary cladding profiles in the UK market.
Lunawood ThermoWood Performance Data
For architects and specifiers, here is the key technical data for Lunawood ThermoWood in UK external cladding applications:
| Property | Lunawood ThermoWood | Untreated softwood |
|---|---|---|
| Durability class (BS EN 350) | Class 2 — Durable | Class 4–5 — Not durable |
| BRE service life (cladding) | 30 years accredited | 5–15 years with treatment |
| Moisture absorption | Reduced by up to 50% | High — prone to movement |
| Dimensional stability | Excellent — minimal movement | Poor — significant seasonal movement |
| Resin content | ✓ Resin-free — eliminated in process | Present — can bleed at high temperatures |
| Chemical treatment required | ✓ None | Yes — preservative treatment needed |
| Thermal conductivity | Reduced — better insulation | Standard |
| Certification | PEFC — sustainably sourced | Varies by supplier |
| Fire rating (optional) | Euroclass B-s1,d0 available — see our fire treatment service | Euroclass D–E untreated |
Lunawood ThermoWood Profiles Available in the UK
Lunawood ThermoWood installed vertically — the profile works equally well horizontal or vertical, giving architects full flexibility in facade design.
We stock the following Lunawood ThermoWood profiles for immediate delivery across the UK. All profiles are available in the standard uncoated finish — a uniform warm honey-brown colour that weathers naturally to silver-grey over time. Factory-applied finishes are available on request through our factory coatings service.
Lunawood Triple Shadow Gap — The UK's Most Popular Profile
Lunawood triple shadow gap — the three recessed grooves create a strong horizontal rhythm that defines the look of many of the UK's most admired contemporary timber facades.
The Luna triple shadow gap profile is the product most associated with Lunawood ThermoWood in the UK specification market. Its three precisely machined shadow grooves create a horizontal pattern across the facade that is both refined and visually distinctive — the kind of detail that makes a building look designed rather than simply clad.
The profile is available in two sizes to suit different project scales. The 26x92mm triple shadow gap is the most popular for residential projects and garden rooms — its narrower board width creates a more frequent horizontal rhythm that suits smaller elevations. The 32x140mm triple shadow gap suits larger facades on commercial buildings, house extensions, and new build homes where a bolder, more architectural statement is wanted.
Both sizes install in identical fashion — horizontally over a ventilated batten framework — and both accept the same finishing options. The shadow grooves are self-draining, making this one of the best-performing profiles in the UK's wet climate.
Lunawood Double Shadow Gap
Lunawood double shadow gap 26x142mm — a wider board with two grooves creates a bolder, less frequent horizontal pattern suited to larger facade areas.
The Luna double shadow gap 26x142mm is the natural companion to the triple shadow gap on larger projects. The wider 142mm board face and two shadow grooves create fewer horizontal lines across the facade — a more monolithic, architectural result that works particularly well on tall elevations where a more restrained visual rhythm is preferred.
The double shadow gap is increasingly specified on commercial projects, school extensions, and high-end residential new builds where the brief calls for a considered, precise facade rather than a heavily patterned one. It is available from stock for nationwide delivery and accepts all the same finishing options as the triple shadow gap range.
Lunawood ThermoWood Species — Pine and Spruce
Lunawood Thermo Pine — Nordic pine thermally modified to Durability Class 2, producing a warm honey-brown tone and tight, consistent grain suited to precision-machined shadow gap profiles.
Lunawood ThermoWood is produced from two Nordic species — pine (Pinus sylvestris) and spruce (Picea abies). Each has slightly different characteristics that suit different applications:
Lunawood Thermo Pine
Nordic pine is the primary species used for Lunawood exterior cladding profiles. Its tight, even grain structure machines precisely to produce the clean shadow groove edges that define the triple and double shadow gap profiles. Fresh Thermo Pine has a warm honey-brown colour that weathers gradually to silver-grey. It is the species used in most Lunawood shadow gap, tongue and groove, and rainscreen profiles.
Lunawood Thermo Spruce
Nordic spruce is used for some Lunawood interior profiles and wider-format exterior boards. Its longer, straighter grain sections allow wider board dimensions than pine — useful for projects requiring boards wider than 140mm. Thermo spruce has a slightly lighter, more rustic appearance with more prominent knot character than pine, giving it a warmer, more natural aesthetic suited to projects where a less clinical finish is wanted.
Finishing Options for Lunawood ThermoWood in the UK
The Lunawood ThermoWood collection — available in the UK in shadow gap, double shadow gap, tongue and groove, and rainscreen profiles from stock.
Lunawood ThermoWood can be left unfinished, finished on site, or supplied factory-coated. Each approach suits different project requirements:
- Unfinished (leave to weather) — the most popular low-maintenance approach. Lunawood weathers naturally to a consistent silver-grey without any treatment. This is a genuinely attractive, maintenance-free finish that many architects actively specify. No ongoing treatment needed beyond occasional cleaning.
- UV-stable exterior oil (site-applied) — maintains the original warm honey-brown colour and extends the period before weathering begins. Apply every 3–5 years depending on exposure. Compatible products include Koopmans Houtolie and Remmers HK Stain from our fixings and woodcare range.
- SiOO:X silicone treatment — produces an instant silver-grey finish rather than waiting for natural weathering, and maintains consistent colour over time. Popular on projects where a grey finish is wanted from day one without the wait.
- Factory coatings — coloured stains and pigmented finishes applied under factory conditions before delivery. Contact our team via our factory coatings service for available colours and lead times.
For most UK projects, leaving Lunawood ThermoWood unfinished is the simplest and most cost-effective approach — the silver-grey weathered finish is attractive, consistent, and genuinely maintenance-free. If you want to maintain the original honey-brown tone, apply a quality UV-stable oil within 2–4 weeks of installation before initial weathering begins. Re-apply every 3–5 years on south and west-facing elevations.
Where to Buy Lunawood ThermoWood Cladding in the UK
Lunawood ThermoWood cladding on a UK project — supplied by Timber Cladding Specialists with nationwide delivery in 7–14 days from stock.
We are a specialist UK supplier of Lunawood ThermoWood cladding, stocking the most popular profiles for immediate delivery across the UK. We are FSC and PEFC certified, hold awards from the Build Architecture Awards 2021 and the London & South East Prestige Awards 2022, and supply Lunawood cladding to homeowners, architects, contractors, and developers nationwide.
Our Lunawood stock includes triple shadow gap in both 26x92mm and 32x140mm, double shadow gap 26x142mm, shadow gap 19x117mm and 19x140mm, and tongue and groove 19x140mm. All profiles are available from stock with delivery in 7–14 days. For fire-rated projects, Lunawood boards can be supplied with Euroclass B-s1,d0 certification through our fire retardant treatment service.
To order or request a quote, contact our team with your required profile, dimensions, total m², and delivery postcode. We will provide a precise material quantity, cost, and delivery timeline. For more on ThermoWood performance generally, see our ThermoWood cladding performance guide and our complete ThermoWood guide.
Lunawood ThermoWood is thermally modified timber produced by the Finnish company Oy Lunawood Ltd. The timber — typically Nordic pine or spruce — is heated to 185–215°C in a steam environment without chemicals, permanently improving its moisture resistance, dimensional stability, and natural decay resistance. The result is a durable, low-maintenance cladding material with a BRE-accredited 30-year service life for external applications. Lunawood is PEFC certified and widely specified by UK architects for contemporary residential and commercial facades.
Lunawood ThermoWood cladding is available from Timber Cladding Specialists, a specialist UK supplier based in March, Cambridgeshire. We stock Lunawood shadow gap, triple shadow gap, double shadow gap, and tongue and groove profiles for nationwide delivery in 7–14 days. All profiles are FSC and PEFC certified. Contact our team with your m² requirement and we will provide a quote with full lead time and delivery details.
The Lunawood triple shadow gap profile has three recessed grooves across the face of each board, creating a finer, more frequent horizontal rhythm. The double shadow gap has two grooves, producing a wider board appearance with bolder, less frequent joint lines. Triple shadow gap (26x92mm or 32x140mm) is the most popular for contemporary UK facades. Double shadow gap (26x142mm) suits larger facade areas where fewer joints are preferred.
No. Lunawood ThermoWood does not require preservative treatment for exterior use in the UK. Left untreated, it weathers naturally to a consistent silver-grey. If you prefer to maintain the original warm brown tone, apply a UV-stable exterior oil every 3–5 years. No other treatment is required.
Lunawood ThermoWood has a BRE-accredited service life of 30 years for external cladding, classified as Durability Class 2 (BS EN 350). Correctly installed with a ventilated cavity, appropriate flashings, and minimum 150mm ground clearance, Lunawood cladding regularly exceeds this in UK conditions — 35–40 years is achievable.
Buy Lunawood ThermoWood Cladding in the UK — From Stock
We supply Lunawood ThermoWood cladding in triple shadow gap, double shadow gap, shadow gap, and tongue and groove profiles — all from UK stock with nationwide delivery in 7–14 days. FSC and PEFC certified. Fire rated options available. Send us your profile, m², and delivery postcode for a quote.