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Vertical Grain Siberian Larch (VG SILA) is a naturally durable and aesthetically pleasing product. It is particularly popular for projects with a requirement for both timber cladding and decking; using SILA can create a consistent look throughout the exterior of the project. 


Russwood’s VG SILA boards come in a warm mix of colours, from light reddish brown through to golden browns. The grain of the wood is exceptionally straight and the annual rings are close together. Growth rings mainly run in straight lines on the surface which means minimum risk of surface checking and minimum risk of splinters forming as a result of delamination between the growth rings. When exposed to the elements and sunlight, the colour of the cladding will change to an even shade of grey. If used in a project alongside SILA decking, the weathering of both products will offer consistency of the overall look over time.

VG SILA is supplied as a mix of the highest Siberian larch grades with approximately 70% being virtually clear grade (knot free), resulting in a clean, contemporary timber cladding option.

VG SILA is comprised of vertical and semi-vertical grain boards. Cut from the heartwood with growth rings ranging from 30 - 90°, VG SILA is more stable than flat sawn boards.


The way a cladding board is fixed and detailed can have a major effect on its lifespan. We have teamed up with Austrian fixings specialists, Sihga, to provide a system that makes cladding look better and last longer. We can write these systems into the NBS H21 specification. The VG Sila cladding can be secret fixed with FassadenClip® or face fixed with L-GoFix® stainless steel screws and KompeFix® FassadenClip® provides an ultra clean look with face free of fixings and enhanced durability due to all four side ventilation.


  • Graded to BS1186-3 Part 4 CSH/1; each board is centre pith free, one face will be sap free, through knots have a maximum 25mm diameter and resin pockets although not prevalent are a natural characteristic of Siberian Larch
  • Chipped out knots permitted up to a maximum of 25mm diameter
  • End checks permitted not longer than 1.5 times width of board
  • Kiln-dried to moisture content of approximately 16-18% (+ / - 2%)
  • High density of approximately 628kg/m3 at approximately 16 - 18% moisture content
  • PAR, (Planed all round) 4 chamfered edges – RW212 profile
  • Lengths up to 5.1m supplied in running meters
  • FSC®-certified product sourced from sustainable forests
  • No limitation of splay knots
  • Each board is sap free on face


One of the primary benefits of SILA as a cladding material is that it is one of the toughest and most durable softwoods. It is naturally durable, being rated as Class 3 according to BS EN 350-2. This means that it does not require any chemical treatment.

This natural durability is the result of resin and extracts in the wood, combined with a high density, which reduces the wood's vulnerability to rot, decay and insect damage.

For enhanced durability and improved stability use FassadenClip® for a secret fix solution or, for a face fix option, use KompeFix® with L-Go Fix® screws.

The way cladding is fixed and detailed can have a major effect on its lifespan. Our systems designed by Austrian Timber Engineers will make cladding look better and last longer.


Russwood's VG SILA is more dimensionally stable than standard flat sawn offerings. Flat sawn boards can move up to 50% more than vertical grain boards. This reduced propensity to move means minimal shrinkage and expansion.


SILA is a dense timber, classified by BS EN 350-2 as approximately 628 Kg/m3 at a moisture content of approximately 16 - 18%. As such, it is not easily damaged.

Treatment suitability

Due to the natural durability and beauty of VG SILA cladding, it is generally left untreated to weather to a consistent shade of grey. SILA is suitable for factory coating in SiOO:X, a breakthrough silicone technology, to provide a genuine silver lustre whilst still seeing the figuring of the Larch. SiOO:X creates a weathered appearance at an accelerated rate. Following application, all areas, regardless of protection and exposure, take on a consistent tone which provides a solution to differential weathering. For further information about SiOO:X click here.

Surface Finishes

We can produce Vertical Grain Siberian Larch in a Planed finish - boards are run through our planing mill to create a smooth, dressed finish.


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


VG SILA cladding is supplied in running meters in various lengths up to 5.1m. Please note that cladding is supplied as a linear meterage based on random stock lengths at time of picking order. Other sizes may be available on request.


The standard VG SILA cladding profile is a 27 x 92mm square dressed with bevelled edges.


Please see our cladding comparison table for price range.


  • Aesthetically refined and naturally durable cladding
  • Particularly special when combined with FassadenClip® fixings
  • Ideal for seamlessly blending cladding and decking to weather naturally, or with SiOO:X for an accelerated weathered effect and additional water repelling benefits
  • Natural durability; no chemical treatment required