Protecting larch outdoors

Larch is dense, resinous and highly mobile. That makes it durable but demanding to treat. SiOO:X works inside the fibre and moves with the timber without cracking.

THE ORIGINAL SILICATE WOOD PROTECTION SINCE 1994

What makes larch different

Dense fibre

Larch's dense structure absorbs less liquid. Even application and the correct number of coats are decisive.

Large movement

Larch shrinks and swells considerably. Because silica forms no layer, there is nothing to crack as the timber moves.

Resin bleed

Resinous larch can develop glossy patches. Clean thoroughly and apply in shade for the most even result.

Treating larch

Siberian and European larch are treated the same way. Siberian larch is usually denser and absorbs less.

Coverage on larch

On dense larch, coverage can be slightly higher than on pine and spruce — expect 9–11 m²/litre for Wood Protector. Calculate exact volumes for your dimensions in the calculator.

Frequently asked questions about larch

Does larch need treating at all?

Larch is durable but patinates unevenly and develops surface checks. Treatment controls the appearance and reduces surface moisture movement.

Does it work on Siberian larch?

Yes. Expect slightly lower uptake because of the denser fibre.

Can I treat larch that has already weathered?

Yes, after thorough cleaning with Wood Cleaner down to sound timber.

How often is maintenance needed?

Façades up to 15 years before full renewal; decking Re-Wash + Surface Protector every 2–3 years.