Douglas Fir Cladding Board – Shiplap Profile – 145×18 mm – 4000 mm (13 ft.)

Douglas Fir Shiplap Cladding Board

Douglas fir gives you a handsome, stable softwood cladding at a sensible price, and in long 4 metre boards that carry across a wall with fewer joints to break the line. Fix it for your facade and you get a warm amber grain, a naturally straight lay, and a shiplap profile that laps neatly board over board for a clean, even line. Stocked in our yard for delivery across Ireland, in a 145 mm face at 18 mm thick.

Why Douglas Fir?

Douglas fir is the softwood that behaves. It is one of the most dimensionally stable species we stock, so it stays straight and flat on the wall where lesser softwoods cup and twist. The grain runs long and even in a warm pale amber that deepens as it weathers, and the timber is light enough to lift and fix quickly, which keeps labour down on a big elevation.

Be straight with yourself on durability. Douglas fir is moderately durable, Class 3, not a naturally rot proof hardwood, so it earns its long life by being kept off the ground and ventilated behind. The species is Pseudotsuga menziesii. Resin can occasionally bleed from a knot in strong sun, and a wipe with white spirit lifts it.

Installation guidance

For any competent contractor this is easy cladding to hang. Fix over battens with a ventilated cavity behind, which is what lets the boards dry out and gives you the long life Douglas fir is capable of. Use stainless steel fixings, A2 inland and A4 near the coast, so nothing streaks the face. Dry lay a length first and settle on the coursing before you commit the run. Leave the small expansion gap the profile is designed around at board ends, and keep the bottom edge clear of the ground so water never wicks up into the end grain.

Finishing & maintenance

You have two honest routes. Leave the fir to weather and it drifts to a silver grey over a year or so, the no effort option, and the look is clean and modern. Or hold the amber tone with a penetrating exterior wood oil, which asks for a refresh every couple of years but keeps the colour warm.

Most of our customers oil Douglas fir, because the fresh colour is a big part of why they chose it. Use a breathable penetrating oil and avoid film forming varnishes and thick paints, which trap moisture against a softwood and flake. We stock oils that suit fir, so ask us which to pair with your boards. Either way, an occasional wash with a soft brush and clean water is all the wall needs.