Timber cladding fixings influence far more than whether a board stays attached. Their material, head style, position and relationship with the support system affect appearance, movement, staining risk and the way the façade is inspected or maintained. The correct choice depends on the exact timber, profile, coating, exposure and wall design, so a universal screw or nail specification is rarely responsible. This guide explains the questions to resolve before ordering boards and fixings for a residential or commercial timber façade in the UK.
Start with the board and wall specification
Fixings should be selected after the timber product and wall arrangement are understood. Record the species, grade, finished board thickness, profile, installed cover, orientation and surface finish. Then confirm the support material, batten dimensions, centres, cavity arrangement and any specialist treatment. These details determine the fixing zone and the loads the connection must address.
A profile drawing is more useful than a trade name. Two products described as shadow gap, shiplap or tongue-and-groove may have different shoulders, joint depths and intended fixing positions. A fixing that suits one section may sit too close to the edge, interfere with a tongue or leave the head visible on another.
The designer, supplier and installer should agree which information controls the installation. Product guidance may set out suitable fixing positions or methods, while the project team confirms the substrate, support and site requirements. Avoid ordering a generic box of screws before those responsibilities are clear.
- Identify the exact timber, grade and profile
- Use finished dimensions and installed cover
- Confirm support material and batten layout
- Check treatments, coatings and site exposure
- Follow product and project guidance together
Choosing the material for timber cladding fixings
The fixing material must be compatible with the timber, any preservative or fire treatment, the finish and the surrounding environment. Timber extracts and moisture can react with unsuitable metals and create visible marking or premature deterioration. The risk can be more noticeable on pale boards or beneath repeated rainwater paths.
Stainless-steel fixings are commonly considered for exterior timber cladding, but the appropriate grade still depends on the product and exposure. Coastal or particularly aggressive environments may require different consideration from a sheltered inland wall. Do not assume that every item labelled stainless offers the same suitability.
Ask the timber or profile supplier to state the compatible fixing material and obtain confirmation from the fixing manufacturer where necessary. If the façade includes treated timber, metal trims or other components, review the complete combination rather than considering the screw or nail in isolation.
Screws, nails or a proprietary fixing system?
Screws can offer controlled installation and may be useful where boards need careful alignment or future removal. Nails can support efficient installation on appropriate profiles and projects when their type, dimensions and application follow the relevant guidance. Neither category is automatically better; the connection must suit the board, support and intended appearance.
Head style also matters. A small visible head may create a deliberate, regular fixing line, while another design may call for a more discreet appearance. Power-driven fixings require suitable equipment settings and trial installation so heads are not left proud or driven too deeply into the timber surface.
Proprietary clips and concealed systems can create a clean façade, but they should be treated as complete systems rather than generic hidden accessories. Check which profiles, board dimensions, substrates and orientations they support, how replacement boards are handled and whether the supplier provides a defined installation method.
Visible and hidden timber cladding fixings
Visible face fixing is straightforward to inspect and can form part of the elevation's rhythm when lines are set out carefully. The board and profile guidance should identify the fixing zone, number of fixings and relationship to edges. Consistency is essential: a technically suitable fixing line can still look untidy if it wanders across the façade.
Secret or concealed fixing may use a profile shoulder, clip, rail or another designed connection. It should not be improvised by driving a fixing through an unsupported or vulnerable part of the board. The method must allow the timber to behave as intended and provide the restraint required by the complete system.
Consider maintenance before choosing concealment. Some systems make individual-board replacement more involved, particularly in the middle of a completed elevation. Ask how access, removal and local repair work before accepting a hidden method purely for its appearance.
Vertical timber cladding fixing details
Vertical boards need secure support without blocking the route for drainage and ventilation behind the cladding. The wall may therefore require counter-battens or another designed arrangement rather than fixing directly to horizontal battens that interrupt the cavity. The precise build-up depends on the wall, membrane, profile and project requirements.
Set out support positions against the actual cover width and elevation. Corners, openings, board ends and changes of material may need additional support or carefully placed battens. A generic diagram cannot account for every profile, so the project detail should show where boards finish, how joints are supported and how the cavity continues.
Vertical board-on-board, shadow-gap, tongue-and-groove and open-jointed profiles do not necessarily share a fixing method. Overlap, joint geometry and visible face width change the fixing position. Use a project-specific drawing and a sample panel to confirm the intended line before the main installation begins.
Horizontal cladding and fixing layout
Horizontal shiplap, tongue-and-groove and feather-edge boards normally run across vertical supports, but the joint and fixing zone vary by product. The layout should preserve the intended overlap or engagement without restricting movement or damaging a thinner edge.
Long courses make alignment errors easy to see. Establish level datum lines, coordinate board widths around windows and doors, and decide where length joints will occur. Joints should be supported and arranged according to the product and project details rather than distributed randomly across the elevation.
Corners, starter boards and the upper termination often use trims or specific boards with different fixing requirements. Include these pieces in the material schedule and installation review so the main fixing specification is not applied blindly to every component.
Fixing position, pilot holes and installation control
Fixing position affects splitting, restraint and appearance. Edge and end distances, the number of fixings per support and whether holes are pre-drilled depend on the timber, section and fixing. Dense material, narrow edges or boards fixed close to an end may need particular care, but the exact approach should follow the product and fixing guidance.
A trial area helps establish drill bits, driver settings, head depth and visual alignment. It can also reveal whether a coating marks easily or whether a fixing creates an unacceptable surface effect. Approve the sample using the actual batch, profile and chosen fixing rather than a different offcut.
Site control matters throughout installation. Keep boards protected, reject damaged pieces, check support alignment and inspect the fixing pattern regularly. Correcting a drifting line after several courses or bays have been completed is far harder than catching it on the first panel.
Cedar, larch, Thermowood and treated redwood
Canadian and UK cedar products can differ in density, knot content, grade and profile, while cedar's natural extracts make metal compatibility an important part of the discussion. Ask for the fixing recommendation attached to the exact supplied product rather than copying a detail from another cedar façade.
UK and imported larch can present a denser, more pronounced grain and may require a different installation approach from cedar. Thermowood has product-specific guidance linked to its heat-modified material, and treated redwood requires compatibility with the preservative process and any decorative coating.
Species names do not establish one screw length, diameter or fixing schedule. Finished board thickness, profile geometry, support penetration, exposure and system testing all matter. A useful quotation should therefore pair the proposed cladding product with a compatible fixing option or clearly identify what the installer must source.
Coastal and exposed South West projects
A sheltered Bristol elevation and a coastal project in Devon or Cornwall can expose metal and timber to different combinations of moisture, wind-driven rain and salt-laden air. Share the postcode, orientation, building height and proximity to the coast when asking for recommendations.
Exposed sites also make junctions and water management especially important. Fixings cannot compensate for missing cavity ventilation, inadequate flashings, trapped moisture or poor clearances. The complete façade should drain and dry as intended, with openings and edges detailed by the project team.
Where a project has specialist structural, fire, treatment or regulatory requirements, the relevant professionals should review the complete system and its evidence. Choosing a particular fastener material does not by itself demonstrate compliance for the wall.
What to include in a timber cladding fixing enquiry
Send the project postcode, building type, elevation drawings and approximate area. Identify the precise timber species, grade, profile, finished dimensions, board direction and any treatment or coating. Add details of the substrate, battens, cavity and whether visible or concealed fixing is preferred.
Ask the quotation to separate boards, trims, fixings, finish and delivery so competing offers can be compared on the same scope. Confirm pack quantities and any specialist tools or clips required. A small sample panel can then check the board, joint and fixing together before the full order is released.
The Cladding Centre can help compare timber species, profiles and compatible fixing options for residential and commercial projects across the South West. Send the drawings and site details through the quote page for a project-specific supply recommendation rather than relying on a universal fixing rule.
- Site postcode and exposure
- Timber species, grade and finish
- Profile drawing and finished board dimensions
- Vertical or horizontal orientation
- Substrate, battens and cavity arrangement
- Visible or concealed appearance
- Trims, accessories, quantity and delivery programme