FAQ.

The products that undergo the Linax treatment consist of pine that is impregnated with a copper-based preservative according to NTR class AB, and then boiled in hot linseed oil under vacuum.

Linax is available in the colours Natural, Brown and Grey. Colour variations may occur in Linax timber. The colours are transparent, allowing the natural structure of the wood to shine through – creating a beautiful product with character, depth and a strong wood feel. Heartwood, sapwood and knots absorb different amounts of oil and pigment, which can lead to colour variations in the timber. A slight green tint may be visible initially in Linax Natural and Linax Grey, but this will fade as the product is exposed to the sun’s UV light.

A fine-sawn surface, such as a panel, results in a slightly darker tone and is more colourstable compared to a planed surface such as decking. For Linax Grey, the colour variation can be somewhat greater – we recommend taking a look at our reference images to get a good understanding of how the product appears as a whole. During production, the products are stacked with spacers, which can result in mark traces on the finished product.

All wood requires maintenance – and so does Linax. However, the quality of Linax-treated timber is significantly higher and requires less frequent upkeep. Over time, the oil in the outer layer will wear or wash away due to precipitation, and – just like with other painted timber – the colour pigments will eventually fade. The colour should therefore be refreshed within 5–12 years using the corresponding Linax linseed oil stain with which the product was originally treated.

All screws must be stainless – or acid-resistant in harsh climates. Nail guns should be avoided, as the panel nails tend to penetrate too deeply into the boards, which increases the risk of moisture intrusion around the nail head.

Yes – but it is important that any cut edges or end grains are carefully treated with Linax linseed oil stain.

The raw material for all our Linax products is high-quality Nordic pine.
Pine naturally contains varying amounts of resin.

Resin bleeding may occur on installed Linax timber, especially around knots or in timber with a high resin content. Walls facing south and west, as well as sun-exposed decking, are particularly susceptible. Resin bleeding is not unusual. Over time, the resin will naturally wear away due to weather exposure.

Our recommendation is to let nature do the work.
However, if you wish to accelerate the process, the resin can be carefully removed using a stiff brush – note: not a steel brush. This should only be done once the resin has crystallised and must be carried out during the colder season. Removing resin while it is still soft or actively bleeding will have minimal effect, as the resin discharge will continue.

Resin bleeding on Linax-treated timber is not considered grounds for a claim.

Linax should be stored outdoors in a dry and well-ventilated area, elevated from the ground.
Store the timber in a way that protects it from dirt and moisture – preferably under a roof.
Do not store it fully covered with plastic.

Linax does not need to be sorted as hazardous waste – it can be sent as combustible waste to an approved recycling facility.

Yes, the risk of cracking is lower compared to untreated or traditionally impregnated timber.
The Linax treatment infuses pigment and linseed oil into the wood surface, which reduces cracking and results in more dimensionally stable timber.

No, there is no risk at all.
Although impregnated timber may sometimes feel slightly damp, all metals and chemicals are fully fixed within the wood before leaving Bitus. Skin contact – or livestock licking the timber – generally causes no problems.

We only supply these colours – please see the section on painting further below.

Conventional impregnated timber releases a certain amount of copper over time. The Linax treatment reduces copper leaching from the product to an absolute minimum, which makes Linax a very environmentally friendly choice. Linax is assessed in both SundaHus and Byggvarubedömningen. The raw material for Linax can be sourced as certified, higher-quality timber. Combined with the product’s long technical service life, this gives Linax a strong environmental profile throughout its entire lifecycle.

It is possible to do so, but Bitus advises against using linseed oil soap. Important: Doing so voids the Bitus AB Linax product warranty.

For decking, we recommend an oiling interval of every 5 years, slightly more frequently if the product is exposed to an especially harsh climate. For cladding, we recommend an interval of 10–12 years, and for other products (such as fencing and pergolas) approximately every 8 years.

Ensure that the product is thoroughly cleaned and dry before treatment, and use Linax Oil in the same colour as the timber, following the instructions on the can. Linax-treated timber is fully saturated when newly produced, and applying oil more generously or more frequently than recommended may result in a greasy and sticky surface that tends to attract dirt from the surroundings.

It is important that the timber is cleaned and dry (maximum 20% moisture content) before re-oiling.

It is possible to use Linax Oil on other types of wood, but the end result will not be the same as timber that has been Linax-treated from the start. It also carries a higher risk of biological growth in the form of “black spots,” as the oil has a high linseed oil content.

If the purpose is to achieve a similar shade to your Linax-treated products, we instead recommend tinting a standard exterior wood oil to the desired colour at a professional paint retailer.

If another colour is desired for Linax cladding, the product can be overpainted with a true oil-based paint. All future maintenance must then also be carried out using an oil-based paint.

Important: Doing so voids the Bitus AB Linax product warranty.

The warranty period is 50 years from the date of purchase for rot protection, and 12 years from the date of purchase for shape and colour stability, applicable to all products in the Linax range.

Bitus Thermo pine products are environmentally classified and produced from high-quality northern Swedish knotty pine sourced from certified Swedish forestry. The thermal modification process takes place in a chamber where the timber is heated to 212°C under vacuum and then gently dried. The entire process takes between 36 and 72 hours depending on the product.

The high temperature triggers a series of chemical and physical changes within the wood, resulting in a product that is dimensionally stable and highly resistant to rot and fungi in outdoor environments—without the use of any chemicals.

Bitus Thermo pine products are intended for use above ground and are suitable for façades, decking, noise barriers, windbreaks, fencing, playgrounds, park installations, benches, garden furniture, and interior wall panelling.

ThermowThermowood is a patented method in which the wood is treated in a steam chamber. We use a vacuum-based chamber, which is safer from a production standpoint and provides the product with the same technical properties as wood produced in a steam chamber.

Bitus Thermo pine products contain no added chemicals and can be sorted as wood waste.

Uninstalled material is best stored outdoors in its unopened, original packaging, elevated well above level ground and kept under a roof or covered so that it is protected from direct sunlight, precipitation, and ground moisture. A tarpaulin may be placed over the timber package for a short period, but for ventilation purposes it must not extend all the way down to the ground. Do not open the timber package until immediately before use.

As a newly produced and unpigmented product, it has a beautiful golden-brown tone with natural colour variations, which will break down and even out when exposed to UV light. Its initial scent will also diminish over time. The surfaces are planed smooth, but cutter marks may occur.

The raw material is typically rich in knots, and some cracking in and around knots is normal. Wood is a natural material, and various deformations may occur, such as cupping, warping and surface markings. Insect holes may be present, but the thermal modification process ensures that none of these insects remain alive. Cracks in the material may develop after delivery and installation. Minor defects and marks from packaging and transport may also occur. For fire-impregnated products, slight salt deposits may appear after delivery and installation; these are completely harmless and will wash away with rainfall.

When thermally modified products are installed near swimming pools, reactions may occur between the wood, salt, chlorine and screws. This can lead to oxidation or discoloration around the fixings. This is a natural reaction between these materials and is not considered a defect or grounds for a claim.

All screws must be stainless steel, or acid-resistant in harsh climates. Use a screwdriver or hammer. Nail guns should be avoided, as cladding nails can easily penetrate too deeply into the boards, increasing the risk of moisture ingress around the nail head.

Yes, but before installation all cut edges and end grains should be treated by applying a generous amount of wood oil, as the end grain absorbs more moisture than the rest of the board’s surfaces.

For cladding: bevel-cutting the lower end grain (the so-called “drip nose”) is not recommended for painting and coating purposes.

The thermal modification makes the material more brittle, and the product has reduced strength compared to other wood protection treatments. This means that for decking, closer joist spacing is required. The product is intended for above-ground installation, and good ventilation and air circulation are important.

Keep in mind that surrounding conditions will affect future maintenance intervals, and that adjacent metals or products that come into contact with the timber and are not stainless (such as window flashings, downpipes, furniture or plant pots) may become discoloured.

The products must be installed in a professional manner, and at the time of installation they must be clean and dry.

Bitus Thermo pine cladding can be ordered with optional Fire Impregnation. The fire impregnation is salt-based, colourless, 100% natural and biodegradable, approved for both indoor and outdoor use, and provides the highest possible fire protection rating for wood (class Bs1-d0). Panels for the Swedish market are sold under the SP Fire 105 certification.

On products treated with Bitus Fire Impregnation, some initial surface salt deposits may occur. This is completely harmless and will wash away naturally with weather exposure.

Thermally modified timber requires minimal maintenance and can be left untreated to allow it to weather and grey naturally. However, the product also offers great flexibility for those who wish to paint or treat it to extend its service life. Bitus Thermo pine products are ready for installation upon delivery, and they can advantageously be oiled or painted either before or immediately after installation.

Regular cleaning and oiling can be carried out as desired and/or needed, typically around once per year. For cleaning, we recommend rinsing the product with a garden hose using normal pressure. Never use a high-pressure washer, as it may damage the wood surface.

Choose a high-quality exterior wood oil, with or without pigmentation depending on the desired appearance—preferably water-based for environmental reasons—purchased from a well-stocked building supplier, and follow the manufacturer’s instructions.

Fire-impregnated Thermo pine products can be painted or oiled, but it is important to be aware that any additional treatment will affect the fire rating. Therefore, a fire-neutral paint or oil should be used.

For fire-impregnated and pigmented Thermo pine cladding treated according to the OneLayer system, the pigmentation is intended to last for the entire service life of the product. The natural weathering and greying of the wood will gradually emerge over time, and such panels should therefore not be maintained or overpainted. Painted Thermo pine cladding that has been factory-primed and base-coated should be finish-coated according to the separate instructions provided upon delivery.

The expected service life of thermally modified decking is approximately 10–15 years, and for thermally modified cladding approximately 20–25 years. This is largely dependent on factors such as ventilation during installation, surrounding conditions including exposure and nearby vegetation, as well as maintenance.

Bitus Thermo pine products contain no added chemicals and have a natural and intrinsic wood protection that gives the product strong durability. They are also an obvious choice from both an environmental and health perspective due to their highest environmental classification.

Bitus Thermo pine products (both planed and fire-impregnated versions) are Nordic Swan Ecolabelled and are assessed in both SundaHus and Byggvarubedömningen.

The products are also Nordic Swan Ecolabelled and included in SundaHus and Byggvarubedömningen in their fire-impregnated version (not painted).