Faq

Siberian Larch is a softwood timber species, the botanical name is Larix sibirica. Siberian Larch is also known as Russian Larch. The timber is moderately durable and used for a wide range of joinery application such as cladding, decking and garden furniture manufacture.The Siberian larch tree is a medium-sized deciduous, coniferous tree ranging in size from 20m to 40m tall with a diameter of 1m or slightly more. In favourable situations, a long, clean, cylindrical bole for two-thirds of its length can be achieved.

The density of Siberian Larch is 590 kg/m3 (mean, Kg/m³) and ranges from 570 kg/m3 to 650 kg/m3

The colour of Siberian Larch ranges from brown (Golden brown), Light brown, Reddish brown (Pale)

Similar to European larch in that it saws, machines and finishes well but it tends to split on nailing and therefore drilling is recommended particularly at board ends.

The best quality and durable Siberian larch grow in the colder regions of Siberia to Mongolia, the bulk of the larch comes from Russia hence the name Russian Larch. The native distribution for Siberian Larch L. sibirica extends across Siberia to Mongolia and northern China. In Siberia, it is extracted from ‘natural forest’ and most of this timber is extremely slow grown material. In the eastern part of its range, it hybridises with L.gmelinii and is known as Larix x czekanowskii. L.sibirica is also grown in plantations in Austria, Norway and Finland yielding more quickly grown material. It has been introduced into Canada and the northern USA.

Siberian Larch can be stained, it is important to make sure that the Siberian Larch is well kiln dried 18% moisture content and below. This is best done in a factory controlled environment a number of the timber cladding and decking producers supply factory stained Siberian larch.

Siberian Larch can be painted, the moisture content should not exceed 18% prior to painting. It is best to buy Siberian larch ready factory painted from the timber supplier  as this is painted under factory controlled conditions.

Siberian larch unpainted or stained will go silver as part of the weathering process. The weathering process of Siberian larch as any timber is a combination of various processes weathering includes weather elements rain wind, temperature, sunlight and mould on the wood surface. Siberian larch will go silver quicker when exposed to the exterior elements of rain, sunlight etc.

Siberian Larch does not require treatment against biological attack mould and fungi that is for most applications when used above ground use class 3 for decking and cladding situations. If it is used for direct ground e.g posts and poles it needs to be treated. Siberian larch does not take pressure preservative treatments very well due to the tight structure and the high resin content. You will need to fire retardant treat Siberian larch if you need to improve the fire resistance or to improve the fire performance of the timber cladding e.g to Euro Class B, or Euro C EN 13501-1 or Class 1 or Class O in BS476 Part 6 and 7

Siberian larch like most timber when used for cladding applications in thickness of 18mm and above in standard cladding configurations this is generally classified as Euro Class D and is a self-declaration for CE Marking for timber cladding BS EN 14915:2006 Solid wood panelling and cladding.

Siberian Larch is moderately durable it is important to make note of the origin of Siberian larch is has to be slower grown and heartwood. The Siberian larch when used for cladding and decking applications and well detailed should last more than 25 years.

We have detailed Siberian larch cladding installation guidelines, showing the different configurations and batten sizes both cladding battens and counter battens. We have included different cladding weatherboarding configurations. We also give the cavity required for air circulation and breather membranes and insect mesh.

Siberian larch needs to be installed with annular ring shank stainless steel nails or stainless steel screws. For most Siberian larch cladding with a thickness of 15mm to 25mm use nails that 51mm long.

Siberian larch will weather into a silvery grey when exposed the elements, the weathering process occurs at different rates depending on the exposure elements and the intensity on the external elements. Siberian larch that is unexposed will turn silvery grey quicker to partly covered or covered Siberian larch there is not a fixed rate of weathering. The timber will turn dark brown before turning into silvery grey, in instances that the cladding has developed water stains or watermarks these do not become very visual as the weathering process evens out the colours. The colour difference is very distinctive in the early stages of weathering.

The colour of Siberian Larch ranges from brown (Golden brown), Light brown, Reddish brown (Pale), there is a distinction between the heartwood and sapwood which is paler.

Siberian larch can be cleaned by jet washing in areas with no staining or painting, stains in Siberian larch can be removed by using a wood reviver. For painted or stained or oiled Siberian larch – For factory finished Siberian larch touch up all exposed ends and splits or checks as they develop and use a soft, lint-free cloth or a large sponge and a neutral pH soap to remove any pollutants and scrap off any resin as part of the annual maintenance.

Siberian Larch is good for decking as it is naturally durable, dense and does not need any preservative treatment, it can be oiled and stained

Siberian larch is used in a number of projects as is readily available, affordable, durable, no toxic, beautiful and can be enhanced with a number of techniques such as shou sugi ban, charring, burning, painting, oiling staining. It can be used for various joinery applications decking, cladding, garden furniture, windows and doors.

 

Siberian Larch is available in a wide range of standards for sawn Timber this is supplied based on the GOST grading rules U/S (I-III) Unsorted, S/F Sawfalling (I-IV) or Vth Fourths etc

Siberian Larch is graded as follows for cladding 2 standards are used BS1186:3 1990 Part 4 for knot size and BS8605:2014 External Timber Cladding Part 1 – Method of Specifying.

BS1186:3 1990 (Timber for and workmanship in joinery) is the current British Standard relating to cladding. The definitions of quality largely relate to visual quality and the size and frequency of knots -classes are defined:

Grade A+ 

 This is virtually a clear grade timber, providing a clean, consistent, almost knot-free look combined with excellent durability. 

    • Graded to BS1186-3 Part 4 Class 1; each board is practically centre pith free, one face will be sap free

    • Further hand-selection of clearest grade boards which meet stringent criteria; tight live knots with a maximum 12mm diameter and a maximum of two knots per metre on average over the total length of boards

    • As Siberian Larch is imported to the UK in board form, to avoid unsightly surface finishes such as circular-saw marks, paint / grease marks and compression marks from steel securing bands

    • Kiln-dried to moisture content of approximately 16-18% (+/- 2%)

    • End checks permitted not longer than 1.5 times width of board

    • Best available grades in Europe and guarantee that your order will not contain any commonly available, lower quality grades such B or BC

 

Grade A/B

    • Graded to BS1186-3 Part 4 Class 2; each board is practically centre free, one face will be sap free, tight live knots have a maximum 35mm diameter and a maximum of two knots per metre on average over the total length of the boards

    • Kiln-dried to moisture content of approximately 16-18% (+/- 2%)

    • End checks permitted not longer than 1.5 times width of board

    • The best available grades in Europe and guarantee that your order will not contain any commonly available, lower quality grades such B or BC