Cedar Cladding Feature Wall
A vertical cladding feature for a garden room, gable end or boundary wall — coverage, battens, movement gaps and species choice explained.
What you'll need
Materials
- Cladding boards (feather-edge, shiplap or rainscreen profile), 38×25 or 25×50mm treated battens, breathable membrane (e.g. Tyvek or Solitex), insect mesh for the open base, stainless A4 ring-shank nails or screws, corner trims.
Tools
- Circular saw or table saw, impact driver, spirit level, chalk line, staple gun for membrane, snips for breathable tape, ladder or low scaffold tower for anything over 2.4m.
Material complexity: High
Allow 12–15% on boards for cuts around ends and board selection. Order battens by total run length plus 10%.
Main risk: No ventilation cavity, or boards fixed straight to the wall — moisture is trapped and the cladding fails from the back.
Cut list
About 8m² of wall. Allow 12–15% extra on boards for cuts, ends and the boards you reject.
- Cladding: about 70 linear metres of 18×144mm feather-edge (or 21×145mm shiplap). Buy 1.8–3.6m lengths
- Battens: about 16m of 38×25mm treated, fixed vertically at 600mm centres
- Breathable membrane: 8m² plus overlaps — a 10m² piece or a short roll
- Insect mesh: the full width of the wall at the open base, plus 200mm spare
- Corner trims for the two vertical edges
- Stainless A4 ring-shank nails or screws for cedar or coastal work; A2 on treated redwood inland. Typical 50–65mm, one fixing per board per batten, 25mm in from board ends
Step-by-step
Set out the wall and fix the membrane
Measure the wall and mark a dead-level line for the first board. Staple breathable membrane to the wall, running it like roof tiles — upper sheet over lower — so water cannot get behind a joint. Leave extra at the base and the head.
Tip: The stack from the wall out is: membrane, vertical batten (the air gap), then cladding. Do not fix boards straight to the wall.
Watch out: A plastic sheet that cannot breathe will trap moisture. Use a membrane made for timber cladding.
Fix vertical battens and the insect mesh
Fix 38×25mm treated battens vertically at 600mm centres. They create the drying cavity. Fit insect mesh across the open base so the gap can breathe but insects cannot nest. Check every batten is plumb — cladding follows the battens.
Tip: On a true rainscreen (vertical boards) add horizontal battens first, then vertical ones, so water can run down and out.
Set the first board dead level
The first course sets every board above it. For horizontal feather-edge or shiplap, start at the bottom, at least 150mm above the ground. Check level twice. Fix with one stainless nail or screw per batten, above the overlap line, 25mm in from the end of the board.
Watch out: Two fixings across the width of one board will split it within a season as the timber moves.
Work up the wall, one board at a time
Keep the overlap consistent (about 30mm on 18×144mm feather-edge). Use a spacer block if you are leaving a shadow gap. Pre-drill near ends. Joints between lengths should land on a batten, never in mid-air, and should be staggered so they do not stack one above another.
Trim the edges and check the vents
Fit corner trims or mitred external corners — do not leave a raw butt joint at a corner. Check the base and head can still breathe. Oil now if you want to keep the colour; cedar and larch can also be left to silver.
Tip: Walk away and look from the garden before you call it done. A wandering first course is obvious from ten metres.
Tips & traps
- No ventilation cavity — the most common and most expensive mistake.
- Fixing boards directly to membrane or wall.
- Two fixings per board per batten — splits the board as it moves.
- Skipping the breathable membrane, or using a sheet that cannot breathe.
- Boards too close to the ground — they wick moisture and rot from the bottom.
Planning & timber detail
Why build this?
Cladding transforms a flat wall like nothing else, but only if you respect the stack: membrane, battens, cavity, cladding. This project teaches that sequence properly. It is also one of the most satisfying timber projects to look at once finished.
Where it works best
Walls that get reasonable airflow and do not sit constantly in shade. Brilliant on the sunny side of a garden room or as a south-facing accent wall. Avoid north-facing walls in heavy shade unless you accept faster algae growth.
Planning notes
From the wall outward: breathable membrane, vertical batten (the ventilation cavity), then cladding fixed to the battens. No direct cladding-to-wall fixing. Plan for at least an 18mm cavity and continuous bottom and top vents protected by insect mesh.
Typical sizes
Worked example: 8m² wall in 18×144mm feather-edge with 30mm overlap — about 70 linear metres of board plus 16m of battens.
Boards commonly run 1.8–3.6m. Order lengths that minimise joints on the visible face.
Cavity 18mm minimum; 25–38mm is more comfortable. Keep the lowest board at least 150mm off the ground.
Default dimensions
Worked example: 8m² feature wall.
Boards: 18×144mm feather-edge with 30mm overlap, or 21×145mm shiplap.
Battens: 38×25mm vertical at 600mm centres.
Keep the lowest board at least 150mm off the ground.
Design variants
Horizontal feather-edge or shiplap — the usual UK look. Work bottom-up from a dead-level first board.
Vertical rainscreen — 22×95–145mm boards with a consistent gap. Counter-batten (horizontal then vertical) so the cavity can drain.
Treated redwood vs cedar — redwood is the lower cost band; cedar is lighter to handle and can be left to silver.
Suitable timber options
Cedar is the safe default for a feature wall — light, stable, forgiving, ages gracefully. Larch is the value choice for larger areas and reads slightly more rustic. Thermowood gives the cleanest, most dimensionally stable result if you want minimum movement and a uniform finish.
Fixing and finishing
Stainless A4 for coastal work and for oak or chestnut; A2 on treated redwood inland. Fix above the overlap on shiplap and feather-edge so the next board hides the head. One fixing per board per batten — two across the width will split the board as it moves. Keep fixings 25mm from board ends. Typical length 50–65mm.
Start with a perfectly level first course — every board after is set by it. For horizontal feather-edge or shiplap, work bottom-up. For vertical rainscreen, work from one corner with consistent gaps using a spacer block. Mitre external corners or use a proprietary corner trim — never butt-jointed.
Maintenance
Walk past once a year and look for any board that has split, cupped or worked loose. Brush down algae in shady areas. Check the bottom edge and insect mesh for blockage by leaves or soil.
If oiled, plan to recoat the south/west face before the north — UV breaks the finish down faster. Replace any individual failed board rather than re-cladding sections.
Timber behaviour
Durability
Use Class 3 (UC3) treated battens are non-negotiable — they sit in the wet zone behind the cladding. UC3 means timber kept off the soil (above ground). Cladding itself can be an untreated durable species or UC3 treated. Keep any timber at least 150mm off the ground. You do not need UC4 (timber that sits in soil or stays wet) unless a batten or plank can touch soil.
Movement
Cladding boards expand and contract with seasonal moisture. Fix each board with a single nail/screw per batten so the board can move — never two side-by-side. Allow 3–5mm expansion gaps at ends and around openings.
Go deeper
Get the Timber Buying Companion
An 8-page practical guide to choosing better boards, avoiding waste and spotting common timber problems before you buy.