Siberian larch timber properties
The unique properties of the Siberian larch have proven themselves. Siberian larch has been widely used in shipbuilding, house building, and construction. It is no coincidence that Venice stands on poles made of Siberian larch. Centuries later, Venetian scientists examined the stakes and found that they were petrified. The Siberian larch has been widely used in construction over the past centuries. Average lifespan 50-100 years. Siberian larch wood is similar to Western Red Cedar. Better durability properties can only be achieved with Accoya wood.
Siberian larch is characterized as high quality wood with natural aesthetics and decorative properties. It is able to retain its properties without additional treatment, varnishes or special impregnations, maintaining a natural balance. Siberian larch wood has high antioxidant properties – in other words, it can renew cells. Therefore, living around larch materials means to prolong youth and imperceptibly fight against diseases.
Siberian Larch timber is a good choice for a wide range of projects from large-scale construction to small self-builds. It is popular with architects and construction companies alike due to its aesthetic beauty, durability and longevity. The wood is shockproof, easily tolerates changes in temperature and humidity, is not prone to rot and is naturally resistant to insect attack.
Siberian larch is an excellent material that can keep excellent appearance and high performance for many years. The remarkable properties and unique performance characteristics of the Siberian larch have led to it being referred to as the “Tree of Eternity”. The timber is resistant to rot when in contact with the ground, and is suitable for use as posts and in fencing. Top quality timber is in great demand for building yachts and other small boats, for exterior cladding of buildings, and interior paneling. In Central Europe larch is viewed as one of the best wood materials for the building of residences.
Additional features & benefits include: high natural resistance, great durability – long lasting, high density, very hard, natural pleasant look and touch along the natural grown annual rings, no lines from band saw or other technologies.
Wood type: | Siberian larch (Larix sibirica) |
Timber treatment: | None |
Density: | In dry state approx. 628 kg m³ |
Lifespan: | Proven life expectancy of 50+ years |
Quality class: | Sawfalling I-IV |
Construction grade: | C24 |
Humidity: | Dried up to approx 16-18% (+/- 2%) |
Purpose: | Outdoor use |
Other uses: | Decking, Cladding, fencing, joinery, flooring |
Dimensions (mm): | 25 x 100 / 125 / 150 mm |
Origin: | Sustainable forests of Northern Russia (Siberia) |
Available length: | From 2 to 4 m |
Appearance: | The wood come in a warm mix of colours, from light yellow brown through to golden browns with a strong grain, similar to pine. Depending on the grading, the boards may contain a few dark knots. |
Weathering: | When the boards weather, the color changes to beautifully consistent silver gray, which is highly desirable in many projects. |
Insect attack: | Resistant |
Treatability class: | Resistant |
Movement class: | High (A 145mm board can vary 3-4mm over the year.) |
Impact resistance: | High |
Scratches and abrasion: | Resistant |
Fire treatment: | Possible by impregnation |
Working characteristics: | Good workability. Receives fixings satisfactorily. |
Extracts: | Siberian larch is more likely to contain resin than oil or tannin. The resin is fixed by firing and does not tend to bleed out. Larch is fairly consistent and non-reactive and, as such, becomes relatively evenly weatherproof. |
When to fix: | Ideally autumn / winter months. |
How to fix: | Face fixation with stainless steel ring thigh nails. Pre-drilling recommended. |
Siberian Larch wood is naturally durable (Class 3 according to BS EN 350-2) – and therefore ideal for outdoor purposes – due to a combination of factors:
- The chemical composition of the wood creates a high resistance to rot and decay, which makes Siberian Larch one of the hardest and most durable softwoods.
- High density – this means that it is more difficult for decaying organisms to penetrate the wood.
- Long lifespan – lifespan of approx. 50-100 years with correct detailing and general outdoor exposure. Better durability properties can only be achieved with Accoya wood.
The natural durability of Siberian Larch means that no treatment of the wood is required and any coatings applied are for aesthetic purposes only.
Due to the high percentage of heartwood (75-90%) and the minimal proportion of sapwood, Siberian Larch is an extremely dense timber, which is classified by BS EN 350-2 as approximately 630 kg / m3 with a moisture content of 18%. As such, it is not easily damaged, making it ideal for highly exposed elevations, or applications where there is a likelihood of damage such as bumps or scratches.
The extreme continental climate in Siberia (Russia) produces a high proportion of late wood, which provides enhanced dimensional stability and enables a smoother machine finish.
In addition, our Siberian Larch is kiln-dried to around 16-18% (+/- 2%), the optimal moisture content for outdoor use. This moisture level is retained until delivery on site, so your Siberian Larch wood can be installed immediately. The benefit of kiln drying Siberian Larch, as opposed to air drying it, is that the timber dries uniformly and therefore achieves optimum stability.
Improved dimensional stability performance can be achieved by using narrower widths, for example 50mm and 100mm.
Our Siberian larch sawn timber available in various lengths, from 2m up to 4m. The standard board dimension is approx. 150mm, as this is traditionally the most commonly produced width. However, we also offer a range of other widths: 100mm, 125mm and 175mm. The narrower board widths offer a number of advantages, including a wider choice of design options and improved dimensional stability. As an added benefit, narrower board widths are generally rated well beyond their specification.
Siberian larch sawn timber is supplied per linear metre based on random stock lengths at the time of order picking. Other sizes may be available on request.
- Stainless steel is a good policy no matter what you are installing but this wood contains tannins that will corrode or cause staining with non-stainless fasteners. Recommended installation is 2-1/2” stainless steel screws through the face installing 16” on center joists. Pre-drill near end of boards to reduce potential splitting.
- For edge spacing, a 3/16″ to 1/4″ free space is recommended. DO NOT fit boards tightly together as you would with pressure treated timber.
- End joints may be joined tightly if desired.
- Siberian Larch is very hard (1100 density) and should be installed more like a hardwood.
- Hidden fasteners are not recommended for Siberian Larch. Similar to the Meranti wood which we don’t stock (which is classified a hardwood, but is actually lower on the hardness scale than Siberian Larch) it is prone to cupping. To solve this, we recommend that Siberian Larch only be face screwed. As of now there is not a Pro-Plug system for this, so fasteners will be visible and you should make your customers aware.
- This can be finished with any high quality penetrating stain or UV protective oil. You now should be aware that Siberian larch if left to gray, the wood turns to more of a brown / gray that may not be as appealing to most customers. Finishing is highly recommended if you want to preserve the natural Siberian larch yellowish / orange colour.
- Last, it’s still wood folks. It is subject to any properties that the Siberian larch or treated timber may display in regard to checking, developing cracks, etc. Wood is wood – you can’t get away from that.
Siberian larch timber quick tips
Sort your lengths. Make sure you’ve set them all up. We recommend ordering 10% more to cover waste material.
Siberian larch is very hard and dense wood. Use professional equipment for best results.
We recommend using only high quality stainless steel screws to avoid corrosion and stains on the wood.
OSMO wood protection offers effective multiple protection against UV rays and harsh environmental conditions.