Board on board cladding — also called board and batten cladding or batten on board — is the most characterful and visually distinctive vertical timber cladding profile available in the UK. Unlike shadow gap or shiplap, board on board is a double-layer system: a first layer of wide boards is fixed to the batten subframe with deliberate gaps between them, then a second layer of narrower boards is fixed directly over those gaps, overlapping the edges of the boards below. The result is a fully weathertight facade with deep three-dimensional shadow lines, bold textural depth, and a strong vertical emphasis that no single-layer profile can match. This complete 2026 guide covers everything you need to know about board on board timber cladding in the UK — what it is, how it differs from other profiles, which species to specify, how it installs, what it costs, and the design applications where it works best.
Siberian larch board on board cladding on a UK house — the double-layer system creates deep shadow lines between the overlapping board faces that change character throughout the day as the angle of light shifts. No other timber cladding profile produces this depth of shadow and three-dimensional texture from natural timber boards alone.
What Is Board on Board Cladding UK — How the Profile Works
Board on board is structurally different from every other timber cladding profile — it is the only standard profile that uses two separate layers of boards rather than a single board with a machined edge joint. Understanding how the system works explains why it looks so distinctive and performs so well:
- Base boards (wide): The first layer of boards is fixed vertically to the horizontal support battens with a deliberate gap between each board — typically 20–30mm. These boards are face-fixed to the battens with A4 stainless steel screws. The gaps are intentional — they are what the second layer covers
- Batten boards (narrow): The second layer of narrower boards — the "battens" — is fixed vertically over the gaps between the base boards, overlapping each edge of the boards below by typically 20–25mm on each side. These are the boards that give the profile its name. They are fixed only through themselves into the structural battens behind — never through the base boards below, which must remain free to move with seasonal moisture changes
- The shadow line: The step between the face of the base boards and the face of the overlapping batten boards — typically 20–28mm depending on board thicknesses — creates the deep shadow line that defines the profile's character. This shadow deepens in raking morning and evening light and almost disappears in flat overhead midday sun — a facade that genuinely changes appearance throughout the day
- Weatherproofing: The overlap of the batten boards over the base board edges — combined with the vertical orientation that sheds water downward — makes board on board one of the most inherently weathertight cladding profiles available, without any machined tongue, groove, or rebate required
Never fix the batten boards through the base boards below. The base boards must be free to expand and contract with seasonal moisture changes — pinning them with a fixing that passes through the batten board above creates stress that will split both boards within a few seasons. The batten boards fix only into the structural support battens behind, clearing the base boards entirely.
Board on Board vs Other Cladding Profiles UK
| Profile | Layer system | Shadow depth | Orientation | Character | Cost vs board-on-board |
|---|---|---|---|---|---|
| Board on board | Double layer | Deep — 20–28mm | Vertical only | Bold, textured, rural/contemporary | Higher (2x boards) |
| Shadow gap | Single layer | Shallow — 4–8mm | H or V | Clean, contemporary, architectural | Lower |
| Shiplap | Single layer | Shallow — 5–10mm | Horizontal | Traditional, weatherboard character | Lower |
| Feather edge | Single layer | Medium — 8–15mm | Horizontal | Traditional, agricultural, rural | Lower |
| Rainscreen | Single layer | None — open joint | Vertical | Contemporary, architectural, open joint | Similar |
The key distinction between board on board and all other profiles is the double layer — no other standard cladding profile creates the same depth of three-dimensional shadow from solid timber boards. See our full timber cladding profiles guide for the complete comparison of every standard profile available in the UK.
Board on Board Cladding — Species Available UK
Board on board cladding on a UK house — the bold vertical double-layer profile with deep shadow lines. The step between the face of the base boards and the overlapping batten boards creates shadow depth that changes throughout the day as the sun moves across the elevation — one of the most characterful timber cladding profiles available in any species.
Where Board on Board Cladding Works Best UK
Board on board cladding on a contemporary UK house — the bold vertical double-layer profile creates strong shadow depth and a distinctive architectural character. The strong vertical emphasis makes the building read as taller and more slender, with a facade that changes character as the sun moves across the elevation throughout the day.
Board on board's rural character is a natural match for barn conversions — the bold vertical boards reference the traditional board and batten barns of the English countryside. Widely accepted by planning authorities on agricultural conversions. See our barn cladding guide.
Bold contrast with existing brick or render — board on board on a contemporary rear extension reads as deliberately different from the host building, signalling architectural intent. The profile depth shows particularly well on large single-storey rear extensions. See our extension cladding guide.
One of the most popular garden room and garden office cladding profiles — the bold vertical character sits naturally in a garden setting and the profile's weathertight performance suits the all-round exposure of a freestanding structure. See our garden room cladding guide.
Increasingly specified on contemporary new build houses where the planning context permits bold natural timber — particularly on rural and edge-of-settlement sites where the agricultural reference of board on board satisfies planning officer expectations. See our new build cladding guide.
The traditional application for board and batten — the profile has clad agricultural outbuildings for centuries. For sheds and garden buildings, Nordic spruce board on board is the most cost-effective specification. See our shed cladding guide.
Board on board used as an accent — one elevation or one section of a building — within a wider cladding scheme that uses shadow gap or shiplap elsewhere. The profile depth creates a strong focal element without dominating the whole facade.
Board on Board Cladding Cost UK 2026
| Species | Supply only | Treatment | Service life | Supply & install |
|---|---|---|---|---|
| Nordic Spruce (untreated) | from £21/m² | Every 2–3 yrs | 15–20 yrs | £55–80/m² |
| Nordic Spruce (pre-treated) | from £25/m² | Every 3–4 yrs | 15–25 yrs | £60–85/m² |
| Siberian Larch | from £50.39/m² | None required | 20–30 yrs | £85–120/m² |
| Charred SSB (spruce-based) | from £60.39/m² | Minimal | 15–25 yrs | £95–135/m² |
| Charred SSB (larch-based) | from £86.99/m² | Minimal | 25–40 yrs | £120–160/m² |
Important — board quantity for board on board: Because board on board uses two overlapping layers of boards, the total board area required is greater than the elevation area being clad. For a standard 25mm overlap each side on the batten boards, allow approximately 1.4–1.6 times the net elevation area in board material — plus the standard 10–15% waste allowance. Always calculate board quantities carefully before ordering. Use our timber cladding calculator or contact us with your dimensions for a precise material list.
All supply and install costs include treated softwood batten system, breather membrane, A4 stainless fixings, and board fixing labour. Excludes scaffold, VAT, and junction detailing at corners and reveals. See our full timber cladding cost guide and our installation cost guide for full pricing breakdowns.
Board on Board Cladding Installation UK — Key Requirements
Nordic spruce board on board cladding pre-treated in a dark finish — the pre-treatment gives an immediate finished colour and extends the interval before the first on-site maintenance treatment is needed. Correct installation of the double-layer system — with the batten boards fixing only into the structural battens, never through the base boards — is the critical detail that determines long-term performance.
Board on board installs on the same ventilated batten system as all other timber cladding — breather membrane, counter battens, horizontal support battens — but with two additional installation requirements specific to the double-layer profile:
- Batten system orientation: Board on board is installed vertically — which means the support battens run horizontally. Install horizontal support battens at maximum 400mm vertical centres (tighter than the 600mm used for horizontal profiles) to provide adequate support across the vertical board span
- Base board spacing: Fix the wide base boards vertically with a consistent gap between each board — typically equal to the width of the batten boards less 40–50mm (to allow for the overlap on each side). Mark out the spacing before you start to ensure even gaps across the elevation
- Base board fixing: Fix each base board with two A4 stainless screws per horizontal batten crossing — one at each third of the board width. Pre-drill within 50mm of all board ends to prevent splitting
- Batten board fixing — critical: The narrower batten boards are fixed centrally over the gaps between base boards — fixing only through themselves into the structural horizontal battens behind. Never drive a fixing through a batten board into a base board below — this prevents the base boards from moving freely with seasonal moisture changes
- Ground clearance: Minimum 150mm between the bottom of the lowest board and finished ground level
- End grain sealing: Seal all cut ends on site immediately after cutting — particularly important on base boards where the bottom cut end is exposed
- A4 stainless fixings throughout: No exceptions — see our fixings guide for the full specification. PFS+ C2 A4 stainless cladding screws are the recommended fixing for all board on board installations
For the complete installation sequence including corner details, window reveals, and base junction see our how to fix timber cladding guide, our corner details guide, and our cladding detail design guide.
Board on Board Cladding Design — Proportions, Shadow Depth & Colour
Deep charred Shou Sugi Ban board on board cladding — the combination of the profile's inherent three-dimensionality with the dark, brushed char surface creates one of the most visually bold exterior specifications available in any material. The shadow lines deepen significantly in raking light; in flat diffuse light the profile face dominates. Larch-based SSB at £86.99/m² gives 25–40 year service life.
Board proportions — base board and batten widths
The proportional relationship between base board width and batten board width defines the visual character of board on board cladding more than any other design decision:
- Wide base, narrow batten (e.g. 150mm base, 50mm batten): The most traditional barn-style proportion — the wide board face dominates, the narrow batten reads as a pronounced vertical line. Strong rural character, bold shadow at the batten edges
- Equal width (e.g. 100mm base, 100mm batten): More contemporary — the alternating equal-width boards create a regular rhythm across the elevation. Shadow depth is consistent; the facade reads as more uniform
- Narrow base, wide batten (e.g. 68mm base, 95mm batten): The most contemporary proportion — the batten face dominates the facade, the base board recesses behind. Shadow lines are shallower but the face of the facade is more consistent. Used on high-specification contemporary projects where the board on board character is wanted with a more refined visual result
Colour options
- Natural/uncoated: Fresh honey-gold (larch) or pale cream (spruce) — weathers to silver-grey over 3–5 years. Zero maintenance on larch; treatment every 2–3 years on spruce
- Pre-weathered/grey: Pre-treated grey stain gives the weathered silver-grey end-state immediately on installation — popular on barn conversions and rural projects where the grey suits the planning context
- Black/dark: Factory-stained black or charred SSB — the boldest option. See our black timber cladding guide for the full specification
- Custom colour: Factory-applied stain in any RAL colour via our factory coatings service — available on larch and spruce boards
What is board on board cladding UK?
Board on board cladding — also called board and batten or batten on board — is a double-layer vertical timber cladding profile. A first layer of wide boards is fixed to the batten subframe with gaps between them; a second layer of narrower boards is fixed over those gaps, overlapping the edges of the base boards. The result is a fully weathertight double-layer facade with deep three-dimensional shadow lines and a strong vertical character. It is the only standard timber cladding profile that uses two separate board layers.
How much does board on board cladding cost UK?
Board on board cladding spruce UK from £21/m² supply only. Siberian larch from £50.39/m². Charred SSB from £60.39/m² (spruce-based) or £86.99/m² (larch-based). All prices ex VAT. Supply and install typically £55–160/m² depending on species. Important: board on board uses approximately 1.4–1.6 times the board area of the net elevation due to the double-layer overlap — factor this into your material quantity calculation.
Is board on board cladding vertical or horizontal UK?
Almost exclusively vertical in UK practice. Board on board is designed for vertical installation — the overlapping double-layer system sheds water most effectively running vertically, and the vertical emphasis of the boards creates the profile's most striking architectural result. The horizontal support battens run at maximum 400mm vertical centres to support the vertical board spans.
What is the difference between board on board and shadow gap cladding UK?
Shadow gap is a single-layer profile where each board has a machined rebate creating a 4–8mm recessed shadow line — precise, contemporary, minimal. Board on board is a double-layer system — wide base boards with narrow batten boards overlapping the gaps — creating 20–28mm deep shadow lines and a bold, three-dimensional texture. Shadow gap is architectural and refined; board on board is bolder and more characterful. Both work vertically; shadow gap also works horizontally.
Does board on board cladding need treatment UK?
Depends on species. Siberian larch board on board requires no treatment — Class 3 naturally durable, 20–30 year service life above ground without any preservative programme. Nordic spruce requires preservative treatment before installation and every 2–3 years throughout its service life. Charred SSB board on board requires minimal maintenance — the char surface provides inherent protection. ThermoWood board on board requires zero treatment — Class 2 durable, 25–40 year service life.
Can I get board on board cladding samples UK?
Yes — we supply free samples of all species available for board on board cladding. Contact us with the species you want to see and we will post samples within 1–2 working days. Seeing the natural grain, colour, and surface texture of larch versus spruce in person — and the different character of fresh versus pre-treated boards — makes the species decision straightforward. See our timber cladding samples guide.
Board on Board Cladding — UK Stock, Free Samples, Nationwide Delivery
We supply board on board cladding in Siberian larch, Nordic spruce, and charred SSB from UK stock. FSC and PEFC certified. Free samples posted within 1–2 days. Send us your elevation dimensions and we will calculate the precise board quantities — both base boards and batten boards — and provide a full supply quote with 7–14 day delivery.