Siberian Larch Cladding

A popular choice due to its aesthetic beauty, excellent durability, high density and impressive lifespan.

Russwood’s Siberian Larch (SILA) is the cladding of choice for many architects, contractors and self-builders, due to the fact that it is extremely versatile - being suitable for all external timber cladding applications - has excellent durability properties and provides a clean, consistent look.  

Appearance

Russwood’s SILA boards come in a warm mix of colours, from light reddish brown through to golden browns.   When weathered the colour changes to a beautifully consistent silver/grey, which is highly desirable in many cladding projects.

With clearly marked annual rings, a straight grain and relatively few knots the overall look is clean, contemporary and, above all, consistent.

Density

Due to its high percentage of heartwood (75-90%) and a minimum of sapwood (we guarantee that at least one face will be sap free) SILA is an extremely dense timber, classified by BS EN 350-2 as approximately 628 Kg/m3 at a moisture content of 18%.  As such, it is not easily damaged and therefore is ideal for highly exposed elevations, or applications where there is the likelihood of physical damage such as knocks or scrapes (e.g. schools, shopping centre, public walkways).

Durability

For external cladding purposes, Siberian Larch is a naturally durable timber (Class 3 according to BS EN 350-2) due to a combination of factors;

  • Resin and extracts in the wood create a high resistance to decay and rot, making Siberian Larch one of the toughest and most durable softwoods in the world
  • High density means that it is more difficult for decaying organisms to penetrate the wood

With a lifespan of 50 -100 years when subject to general outdoor exposure, this is similar to Ruswood’s Architect Select Western Red Cedar.  Better durability properties can only be being achieved with Russwood’s modified timber products; Accoya® wood and Plato®WOOD Fraké. 

Grades and specification

At Russwood we sort and re-grade by hand every Siberian Larch board that we receive, in order to ensure that our stringent in-house grading criteria are met.  We offer two grades; A/B and A+, with the specifications being as stated below.

Russwood SILA A/B®

Russwood offers SILA A/B®, the highest grade of Siberian Larch cladding commercially available in the UK, which provides a clean and relatively knot-free look combined with excellent durability.  The specification for SILA A/B® is as follows;

  • Graded to BS1186-3 Part 4 Class 1; each board is practically centre free, one face will be sap free, tight live knots have a maximum 25mm diameter and resin pockets are restricted to a maximum of one per 2.5m length
  • Kiln-dried to moisture content of 16-18% (+/- 2%)
  • Lengths of 1.8 – 6.0m with 95% of your boards being over 2.4m
  • We select from the best available grades in the UK and guarantee that your order will not contain any commonly available, lower quality GOST grades

Russwood SILA A+

Additionally, Russwood hand-selects boards from the above grade to meet stringent internal criteria for the supply of SILA A+.  This grade is as clear as possible, providing a clean and consistent look with minimal knots.  The specification for SILA A+ is as follows;

  • Graded to BS1186-3 Part 4 Class 1; each board is practically centre free, one face will be sap free and resin pockets are restricted to a maximum of one per 2.5m length
  • 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 length
  • Kiln-dried to moisture content of 16-18% (+/- 2%)
  • Lengths of 1.8 – 6.0m with 95% of your boards being over 2.4m
  • We select from the best available grades in the UK and guarantee that your order will not contain any commonly available, lower quality GOST grades

Stability

Extreme continental climates in Siberia (short, hot summers and long, cold winters) produce a high proportion of late wood, which enables a smoother machine finish and enhances dimensional stability.

Additionally, Russwood’s SILA is kiln-dried to 16 – 18% (+/- 2%), the optimal moisture content for external cladding. The benefit of kiln drying Siberian Larch, as opposed to air drying it, is that the timber dries uniformly and therefore achieves optimum stability. 

Once the kiln-dried Siberian Larch is received at Russwood, this enables machining of the product to achieve a superior finish.  It is then ensured, through the use of stringent quality control processes, that the optimal moisture level is retained until delivery to site.  The cladding can then be installed immediately upon delivery.

Treatment suitability

As Russwood SILA contains very little sapwood when correctly fixed, it does not require maintenance and, if left untreated, will weather to a beautiful silver/grey.

That said, SILA can be fire-retardant treated, using either the NON COM® process, or using HR Prof as an on-site applicant.  Also, due to the infrequent knots and tight grain, optimal paint adhesion can be achieved, particularly when used on smooth sawn surfaces.  Consequently, SILA is an ideal timber for vacuum coating with your choice of colour from Russwood’s Teknos range.

Sustainability

Russwood’s SILA is FSC®-certified, meaning that it is sourced from well-managed forests.

Size

SILA is available in standard lengths of 1.8m up to 6m, in widths of 75, 100, 150, 200 or 225mm and in thicknesses of 22, 25, 38 and 50mm.  Please note that these are standard sizes, but other sizes may be available on request.

Price

SILA is one of our mid-range products, with prices starting at £26 per m2 for sawn boards.

NBS Specification

For advice on completing the NBS H21 for Siberian Larch cladding please get in touch with our technical team.

Summary

  • Clean and contemporary look
  • Suitable for all types of cladding application
  • Excellent density and durability
  • Stringent in-house grading of every board
  • Sustainable

For a printable summary of the above information, click here to download our Siberian Larch Cladding Factsheet

What our customers say about Siberian Larch cladding