SiOO:X

SiOO:X Wood Protection eliminates differential weathering, meaning you can achieve a consistently weathered grey look without the wait. Made from natural and non-toxic ingredients, SiOO:X repels moisture, forming a natural protective barrier to timber cladding.

Thermopine® Clear factory coated with SiOO:X Light Grey - just applied
Thermopine® Clear factory coated with SiOO:X Light Grey – just applied

Consistent weathered finish

Timber, when left uncoated and exposed to the elements, will eventually weather to a silver-grey colour. How quickly and evenly timber weathers is dependent on a variety of factors, including location, aspect and building design. Timber which is sheltered from the elements will take longer to weather, and may result in an uneven or patchy appearance over time. This can take years to even out and in some cases the timber may never weather evenly. SiOO:X eliminates this problem, providing a consistent weathered tone in weeks.

Thermopine® Cladding factory coated with SiOO:X Original (2023)
Thermopine® Cladding factory coated with SiOO:X Original (2019)
Thermopine® Clear factory coated with SiOO:X Mid Grey - 6 months after application
Thermopine® Clear factory coated with SiOO:X Mid Grey – 6 months after application

SiOO:X colours

SiOO:X results in a beautifully even façade, with a consistently weathered appearance. It is available in Original (a clear coating) or in pigmented Light Grey and Mid Grey options. A rapid curing process begins upon application; any initial patchiness will fade out over a period of 10-16 weeks, however, Light Grey and Mid Grey will give more immediate colour to the timber. After 2-3 years, the timber is fully cured and a final colour is reached. The result is a consistent weathered tone, achieved years faster than with natural weathering.

Thermopine RW119 Microtex®, SiOOX Mid Grey | Galmstrup Architects | Nicholas Kane Photography

Burnblock® Fire Retardant

In a groundbreaking development, we are proud to introduce a new offering: our timber coated with both SiOO:X Wood Protection and Burnblock® Fire Retardant treatment. The integrated system has undergone comprehensive fire testing under EN 13501-1, and reaches Euroclass B-s1, d0. This innovative combination empowers architects and designers with the versatility to integrate SiOO:X treated timber into diverse structures, enhancing fire performance and unlocking new possibilities for innovative and sustainable design. This system uses a specially developed version of SiOO:X, available with Russwood’s own audited and CE mark certified process for applying the system on fire retardant treated timber.

The Boathouse | Thermopine® cladding factory coated with SiOO:X Light Grey | WT Architecture | Dapple Photography

Testing and development

Russwood has worked closely with SiOO:X for many years, collaborating on ongoing testing and research and development. Our partnership includes over 12 years of weather testing in the Scottish Highlands, providing valuable long-term performance data and helping to ensure confidence in the system. Today, Russwood is proud to be the exclusive UK supplier and distributor of SiOO:X.

SiOO:X info

What is SiOO:X

Eliminate differential weathering with SiOO:X Wood Protection.

How to apply SiOO:X

Learn more about the proper application of SiOO:X Wood Protection to ensure full penetration of the timber and a consistent finish.

Shop SiOO:X

Proper application of SiOO:X Wood Protection is essential to ensure full penetration of the timber and a consistent finish.

SiOO:X inspiration

View our case studies featuring SiOO:X Wood Protection.

Expert View

I was pleased to learn about SiOO:X wood protection as so much cladding looks great when first installed but then weathers un-evenly. It is now 2 ½ years since we used SiOO:X treated larch on the Build It Self Build Education House and I am delighted with how well it has worked – the cladding looks just as great today as when it was first installed.

Species suitability

The following species are suitable for coating with SiOO:X

Architect Select® Larch

Architect Select® Larch

Architect Select® Larch is Russwood’s premium grade of vertical grain European Larch.

Lunawood Collection

Lunawood Collection

Lunawood Collection is based on Scandinavian design combined with the best technical properties of thermally modified wood.

Scotlarch®

Scotlarch®

Our Scottish Larch (Scotlarch®) is sourced locally and a cost-effective cladding solution.

Thermopine®

Thermopine®

Thermally modified Scandinavian Scots Pine, modified using only heat and steam.

Thermopine® Clear

Thermopine® Clear

Made from clear-grade, thermally modified New Zealand plantation-grown Radiata pine, Thermopine® Clear is distinct from Thermopine® and offers a sustainable alternative to Western Red Cedar cladding.