Owing to its high density Larch has an excellent wear and impact resistance rated BS EN 350 class 3 moderately durability (see below). It's ideal for cladding, flooring page, decking and landscaping projects commercially or for the home garden.
Please note home grown (British) Larch traditionally has more live knots than imported larch. Should you require a hardwood or contemporary finish please see redgrandis.co.uk.
The heartwood is pale reddish-brown to brick-red in colour, sharply distinct from the narrow, lighter coloured sapwood. It is a very resinous wood, with noticeably obvious annual rings a straight grain, and a fine, consistent texture.
It’s wholly sustainable with great supply routes from properly managed forests.
Larch is a like Douglas Fir, a good all rounder. It is good for joinery or furniture work. Super for flooring and excellent as air dried external cladding , looks great with a machined profile because it has a nice machined surface because the grain is nice and fine.
Mechanical Strength: Generally tough and hard with good strength properties (Jap 30% softer than Eu/Sib) and known to be 50% harder than Scots Pine
Durability: Home-grown = slightly durable, Imported = moderately durable Treatability: Extremely difficult although sapwood easier (maybe UK will be easier re: less resin?)
Moisture movement: Small, across the board
Density: 530 (Jap = soft) to 590 t Kg/m3 (dry)
Durability is the ability of a species to resist decay either naturally or through preservatives. The Class is based on the ability of the heartwood (inner part of the tree) to resist fungal decay. The sapwood (the living outermost portion of the tree)is considered not durable and should not be used for external projects without preservative.
BS EN 350 has 5 classes of durability they are:-
Class 1 to 3 can be left as untreated timber, a natural ageing process will accrue e.g. Cedar will turn a grey colour. Class 4 and 5 will need to be treated with preservatives.
For further information see www.greenspec.co.uk/building-design/cladding-durability-quality