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 openings, ends and board selection. Order battens by total run length plus 10%.
Main risk: No ventilation cavity behind cladding — moisture traps and the back of the boards fail within years, even when the front looks fine.
Tips & traps
- No ventilation cavity — the most common and most expensive mistake.
- Fixing boards directly to membrane or wall (no battens).
- Two fixings per board per batten — splits the board within a season as it moves.
- Skipping the breathable membrane or using a non-breathable one.
- Insufficient gap to the ground — boards 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 and gives you the confidence to clad a garden room, an outbuilding, or eventually a whole extension. 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 don't 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 heavily shaded gardens unless you accept faster algae growth.
Planning notes
The make-or-break of any cladding job is the wall buildup. From wall outward: breathable membrane, vertical batten (creating the ventilation cavity), then cladding fixed to battens. NO direct cladding-to-wall fixing. Plan for at least 18mm cavity and continuous bottom and top vents protected by insect mesh.
Typical sizes
For an 8m² feature wall in 18×144mm feather-edge with 30mm overlap, you need around 70 linear metres of board plus 16m of battens. Boards run 1.8–3.6m typically — order lengths that minimise joints in visible areas.
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 (marine grade) nails or screws for any coastal or oak/chestnut work — others can use A2. Fix above the overlap on shiplap and feather-edge so the head is hidden by the next board. Keep fixings 25mm from board ends.
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. Cladding itself can be untreated durable species or UC3 treated. Avoid putting any timber within 150mm of the ground.
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.