Garden Room Cladding Compared

Western red cedar

Naturally durable, light, stable and easy to work. Left untreated it silvers to a soft grey, unevenly at first, with the exposed elevations moving faster than the sheltered ones.

If you want it to stay honey-coloured you are committing to a UV-protective oil every year or two. Most disappointment with cedar comes from expecting it to hold its original colour without that.

Thermally modified timber

Softwood heat-treated to improve stability and durability. It is dimensionally calmer than untreated softwood, takes a dark stain well and is usually more affordable than cedar.

It also silvers over time and is slightly more brittle to work with, so fixing detail matters more.

Larch and other softwoods

Siberian larch is dense, hard-wearing and cost-effective, with a slightly knottier appearance. It weathers to grey and can be left untreated, and it is a sensible choice where budget matters more than a fine-grained finish.

• Cedar: finest appearance, lightest, highest material cost
• Thermowood: stable, mid cost, takes dark finishes well
• Larch: hardest wearing softwood, knottier, most economical
• Composite: consistent colour, no oiling, less natural in close-up

The detailing matters more than the species

Whatever the material, longevity comes from the build-up behind it: a ventilated cavity so the back of the boards can dry, a breather membrane, stainless or appropriate fixings, correct board overlaps and enough clearance from ground level to avoid splashback.

A cheaper board fixed correctly will outlast an expensive board pinned straight to sheathing with no ventilation gap.