The timber from larch (Larix decidua) is highly valued for its tough durable and waterproof qualities making it the perfect choice for external cladding, boatbuilding and fencing. Larch is a mountain tree and seems to prefer long cold winters which have been thought to aid with the ‘ripening’ of the timber.
The longer and colder the winter, the more rest time the tree has and the better and more durable the timber seems to be.
The heartwood can vary from pale reddish-brown to a brick red colour and is stark contrast to the light pale coloured sapwood. It is a very resinous wood and this can often cause problems by building up on cutting blades. The timber can also have a lot of tension in it which, when cut and released, can cause the timber to spring, twist and warp in all directions; this can make for an ‘entertaining’ days work!
Larch is also fairly heavy weighing 590 Kg/m3 when dry.
Larch was first introduced in the UK in the 17th century and is the only deciduous conifer native to central Europe. The most common in the UK are European, Japanese and Hybrid larch.
Hybrid larch, also known as Dunkeld larch, was cross pollinated between European and Japanese larch at the turn of the 20th century on the Duke of Atholl’s estate in Dunkeld.
Hybrid larch is now far more commonly planted than the other two because of its superior growing vigour and high disease resistance.
Piles, which hold the city of Venice above water, are built almost exclusively of the wood of larch and some species of larch are cultivated as bonsai.
Larch can grow to 45m tall and live for 300 years. They are easily identified in the winter as they are the only widely planted conifer to shed their needle-like leaves.
As a very rough guide there is an easy saying to aid with the basic identification of conifers that refers to the way the needles grow from their branches; Spruce-Single needle, Pine-Pairs of needles and Larch-lots of needles growing from the same point on the branch.
Larch leaves are light green and 2-4cm long, they either grow from short woody knobs or shoots on the branches. They turn a beautiful golden yellow before falling in the autumn and are a vibrant lush in the spring.
Larch dries fairly rapidly with an inclination to distort and for knots to split and loosen
When used for external cladding larch is often put on green as it doesn’t split as easily when nailed and is easier to bend into place, but this is only done if cover strips are to be applied; if not, the boards will shrink and gaps will appear.
Rated as a slightly to moderately durable timber, larch is a hard, tough wood that is 50% harder than Scots pine and a bit stronger in bending.
Larch produces a fine, attractive machined surface but it can have issues with the loosening of the knots and can also be prone to splitting if nailed.
Durability : Moderately durable, Slightly durable (homegrown)
Treatability : Extremely difficult – moderately easy (sapwood treatability may vary)
Moisture Movement : Small
Density (mean, Kg/m3) : 550
Availability : Readily available
Price : Cheap
Uses : Joinery -Exterior, Joinery, Cladding, Structural use, Flooring
Colours : Reddish brown (Pale)