Douglas Fir Cladding Board – Rhombus Profile – 65×20 mm – 3600 mm (12 ft.)

Douglas Fir Rhombus Cladding Board

The rhombus profile is the look behind so many sharp modern facades: narrow angled boards fixed with an open gap between them, casting a crisp shadow line and letting the wall breathe. Choose it and you get that contemporary open joint aesthetic in stable Douglas fir, with four rounded edges that catch the light cleanly and shed rain off the angled face. Stocked in our yard for delivery across Ireland, in a 65 mm section at 20 mm thick over a 3600 mm length.

Why Douglas Fir?

Douglas fir is the softwood that behaves, which matters more on an open joint wall where every board is on show from all sides. It is one of the most dimensionally stable species we stock, so the slats stay straight and true rather than cupping where a gap would show it. The grain is long and even in a warm amber that mellows as it weathers, and the timber is light, so a full elevation of slats goes up without a struggle.

One honest word on durability. Douglas fir is moderately durable, Class 3, so an open joint design actually helps by letting air move freely around every face. The species is Pseudotsuga menziesii. A knot may weep a little resin in strong sun, which a wipe of white spirit clears.

Installation guidance

Rhombus cladding is a rewarding fit, though it asks for a little more care than a solid lap. Because the joints are open, fix over a ventilated batten frame lined with a black UV stable breather membrane, so the cavity behind reads as shadow rather than showing bright battens through the gaps. Set a consistent gap between slats, and a story stick keeps it honest across the wall. Fix each slat with stainless steel screws, A2 inland or A4 near the coast, and pre drill the narrow sections near their ends so they do not split. Keep the bottom row clear of the ground so nothing wicks up into the timber.

Finishing & maintenance

You have two honest routes with the fir. Leave it and the slats silver to a soft grey over a year, which suits the clean geometry of a rhombus wall and asks nothing of you. Or hold the amber with a penetrating exterior oil, refreshed every couple of years, if you want the warmth to stay.

Most of our customers oil rhombus cladding, since the fresh colour sets off the shadow lines. Use a breathable penetrating oil and avoid film forming varnishes and thick paints, which flake off a softwood and look tired fast. Oiling is easiest before the slats go up, so every face is reached. We stock the right oils, so ask us which to pair with your boards. Beyond that, an occasional soft brush wash keeps the wall crisp.