01
The cladding board
Boards on battens over a drained, ventilated cavity, open top and bottom. That is what makes it a rainscreen — the standard, not an upgrade.
Specifying
Counter Battens
Timber cladding is not fixed to a wall. It is fixed to battens, and the gap those battens create is what keeps the wall dry — a drained, ventilated cavity, open at the top and the bottom. Get that right and the cladding lasts. Get it wrong and the timber is the least of the problems.
The principle
Correctly installed UK timber cladding is a rainscreen.
Not a style, not an upgrade — the standard way it is done. Boards on battens, over a drained, ventilated cavity that is open at the top and the bottom. Rain that gets past the boards runs down the back of them and out; air moves through the cavity and dries what is left.
That is Timber Development UK's description of a correctly built timber cladding wall, and it is the reason battens are not an optional extra you can save money on. The cavity is doing the work.
"Rainscreen" also describes a profile we machine, which is a different use of the same word. Face fix and secret fix are fixing methods; rainscreen is the wall build-up behind either of them. See the profiles →
02
The fixing
Face fixing — through the board face into the batten, finished flush, never punched below the surface — is the most secure way to install timber cladding. Two fixings per crossing at quarter points for boards 100mm and wider, one central under 100mm.
03
Or no fixing at all, on the face
Secret fixing goes through the tongue, so the finished face is clean. Less pull-through strength, and a single board is harder to replace.
04
The cavity
The build-up is membrane on the wall, then counter battens, then the cladding. The counter battens are what create the ventilated cavity. We would never advise fixing cladding straight onto a membrane.
05
The head of the cavity
Open at the top as well as the bottom, or the air does not move and the timber cannot dry.
06
The base of the cavity
Fit vermin mesh at the cavity base. Keep the bottom of the cladding at least 150mm above ground level — TDUK recommends 200mm — to avoid splash-back and staining, and seal any cut end grain.
Timber Development UK guidance on timber cladding build-ups, verified 2026‑07‑30.
What we supply
Two sizes, in Thermal Pine, square or sloped.
Battens go on the order with the cladding, so they arrive together and in the same timber we would put on a wall ourselves.
- Timber
- Thermal Pine — heat-treated for stability and rot resistance, and the same timber we sell as cladding.
- Sizes
- 42 × 20mm and 42 × 42mm.
- Section
- Each size is available square or sloped.
- Also stocked
- Ventilation strip, supplied on request.
Anything beyond the battens, screws and accessories listed on this page comes from your own merchant — that limit is about fixings and accessories, not about what we make. We mill a good deal more than cladding; ask.
Batten sizes, sections and the ventilation strip are Tiny Temple's own product list (data held with the price engine), stated by the team 2026‑07‑31.
Screws and fixings
Stainless, and not negotiable on some timbers.
What we stock
- Secret-fix profiles — 3.2 × 40mm stainless steel Torx.
- Face-fix profiles — 4.5 × 50mm stainless steel Torx, with 70mm and 80mm also stocked.
- Finish — stainless (silver) as standard. Black screws for black coated cladding, in 4.5 × 50.
What the industry specifies
- Grade. Stainless is the default: A2/304 for general use, A4/316 near the coast or on industrial sites. Aluminium, electroplated steel and brass are unsuitable.
- Acidic timbers stain. Western Red Cedar, oak and Accoya are slightly acidic — non-stainless or galvanised fixings cause permanent black staining. Accoya prohibits galvanised or zinc-plated fasteners, staples and T-nails outright.
- Sizing. Screws minimum 4mm for hardwoods and dense softwoods. Screw length = board thickness + 29mm, giving at least 19mm penetration into the batten. Ring-shank nails minimum 2.3mm, length = board thickness + 24mm.
- Imbue. Abodo asks for minimum 4mm self-drilling, self-countersinking cladding screws with 30mm penetration into a timber batten.
- Metal substrates. Aluminium battens take timber-to-aluminium screws with at least three threads into the metal. For steel framing, follow the support system's own spec — the industry tables cover timber-to-timber only.
Pre-drilling
Board ends are the highest split risk anywhere on the job. Pre-drill fixing points at the ends and keep fixings at least 20mm back from them. Dense species that are prone to splitting want a pilot hole about 70% of the fixing shank diameter.
Larch nailed without pre-drilling needs a 200mm end distance, which is why larch board ends get pre-drilled in practice. Imbue: fixings at least 12mm from the ends, and anything within 70mm of an end pre-drilled about a third smaller than the fastener. Accoya: pre-drill as standard, 1mm under the nail diameter or 80% of the screw shank, fixings at least 50mm from board ends.
Our stock list is company-stated (team, 2026‑07‑31). Grades, sizing and pre-drilling are TDUK, TDCA, Accoya and Abodo guidance, verified 2026‑07‑30. Where a support system has its own documentation, it wins over the general tables.
Detailing
Where cladding fails, it fails at the edges.
Not in the middle of a wall. At the bottom, at the openings, at the corners and at the cut ends — which is where the detailing guidance concentrates.
The bottom of the wall
- Keep the bottom of the cladding at least 150mm above ground level; TDUK recommends 200mm. Below that you are cladding the splash zone.
- Fit vermin mesh at the base of the cavity.
- Seal any cut end grain.
Drip edges
- Cut a 15° back-bevel — a weathering cut — on exposed board ends so water drips clear of the end grain.
- That means the bottom edge of the cladding, and the exposed top ends of vertical boards wherever they are not capped.
Openings
- Properly designed flashing at the sill; consider vertical waterbars at the sides.
- Minimum 10mm gap where board edges meet flashings and sills.
- Keep the drained, ventilated cavity running past the opening.
- Plan opening positions against board widths so the courses work out, and treat every cut end.
Corners and eaves
- Corner cover strips, or blocked corners with an 8–10mm gap to the board ends.
- On an open-jointed rainscreen a neatly mitred open corner with no trim is an accepted alternative.
- Eaves should overhang at least 50mm, or use a flashing.
TDUK, TDCA and Abodo detailing guidance, verified 2026‑07‑30. Industry good practice, not a specification for your building — that is your building professional's job.
Being straight with you
Four things this page does not tell you.
They are the obvious next questions, and we would rather leave a gap than fill it with a number we cannot stand behind. Every figure above has a source. These four do not have one yet.
Still being confirmed
- Batten spacing centres. We publish a 600mm standard fixing centre for the cladding boards; what the counter battens themselves should be set at is a separate question and we are confirming it.
- Cavity depth. How deep the cavity behind the boards needs to be.
- Batten direction. Whether battens run vertically or horizontally, and how that changes with the profile you have chosen.
- Cavity fire barriers. Where they are required.
On the last one, the industry position is clear and we will not go past it: whether a specific project needs cavity barriers, and whether it meets building regulations, is a professional's call. Take it to your building professional — and email us about the rest. Somebody here will tell you what we actually do rather than read you a webpage.
Battens go on the same order.
Price the cladding, then tell us what you need behind it — battens, screws and ventilation strip arrive with the boards rather than from three different places.