Western red cedar is a naturally durable softwood that doesn't need preservative treatment to perform outdoors, which is what makes it a popular cladding choice on extensions and garden buildings.
It behaves very differently depending on how it's detailed underneath — the cavity and fixings behind the boards matter as much as the timber itself.
Where cedar is the right call
Extensions, garden rooms and gable ends where a warm, natural exterior is wanted suit cedar well, particularly where the client is happy for the colour to weather naturally to grey rather than stay a fixed shade.
It also suits projects where a lightweight cladding is an advantage, since cedar doesn't demand heavy support battens or oversized fixings the way denser materials do.
Where it's the wrong call
If the client wants a permanently uniform colour with no visible weathering, untreated cedar isn't the right specification — it will silver unevenly depending on how much sun and rain each elevation gets, and that unevenness is often mistaken for a fault rather than normal behaviour.
On very exposed elevations that are also partly sheltered by an overhang or adjacent structure, cedar weathers at visibly different rates across the same wall, which some clients find acceptable and others don't — it's worth agreeing this before the boards go up, not after.
The ventilated cavity and fixing
Cedar boards are fixed over a battened cavity that allows air to move behind the cladding, drying out any moisture that gets past the boards and preventing it from sitting against the structure.
Fixings need to be stainless steel or another material that won't react with cedar's natural tannins — ordinary galvanised fixings streak and stain the timber over time, showing as dark runs below every fixing point.
Boards can be face fixed, with the fixing visible, or secret fixed through a tongue-and-groove profile for a cleaner look, and that choice affects both appearance and cost.
What we specify instead
Where a client wants the look of timber without the colour variation, we'd point them toward a factory-finished timber-effect composite cladding instead of untreated cedar.
Where the elevation is genuinely very exposed to driving rain, a denser hardwood cladding or a fibre-cement system can be the more sensible choice over cedar's softer, more easily marked surface.
Common questions
Will my cedar cladding definitely turn grey?+
Left untreated, yes — that's the natural weathering process and it happens at different rates depending on sun and rain exposure on each elevation. If you want to keep the original colour you need to plan for a UV oil reapplication regime.
Can cedar cladding be painted instead of left natural?+
It can be stained or oiled rather than left to silver, but painting it defeats much of the point of choosing cedar and adds an ongoing maintenance cycle that a factory-finished alternative would avoid.
Does cedar need a treated timber frame behind it?+
The structure and battens behind the cladding should be appropriately treated or naturally durable, and the cavity needs to stay ventilated — cedar's own durability doesn't extend to what's built behind it.
Talk to us about cedar cladding
We'll look at your elevation, exposure and finish expectations before recommending cedar or an alternative.