Benefits of Lunawood Thermowood

Thermo-D, where D stands for durability, has caramel brown tone. Its durability and stability are improved significantly. Thermo-D is thermally modified at 212ºC and is suitable for internal and external applications without the need for chemical preservative treatment. Patented ThermoWood® process enhances Nordic wood’s properties throughout the wood.

Lowered equilibrium moisture content of Lunawood ThermoWood® makes it dimensionally stable and the material retains its shape far better than untreated wood. The outstanding dimensional stability allows Lunawood to be successfully used in all climates and even in hot and humid weather conditions indoors and outdoors.

Thermo-D is suitable for Use class 3 (EN 335) applications, “situations in which the wood is above ground and exposed to the weather (particularly rain).” It is suitable for use as cladding facades, rainscreen, decking and many other external applications. Lunawood ThermoWood® is not recommended for use in direct contact with the ground.

Thermo-D is classified as durability class 2 (EN 350) “durable” and carries a Building Research Establishment (BRE) endorsement stating an expected service life of 30 years when used as cladding and decking. Durability and colour are consistent throughout the piece.

Lunawood ThermoWood® is not termite resistant. Lunawood can be treated with specialist termite chemical treatments.

Lunawood ThermoWood® is a pure organic material produced using only natural methods – heat and steam – without chemicals.

Thermo-D will not leach colour. Minor release of the color pigment is possible during the first rains and in humid spaces like sauna and spa.

Due to the thermal modification Lunawood ThermoWood® products are pure, safe, and hygienic for indoor use, even for allergy suffers who are prone to wood-related reactions. From the visual point of view, surface treated Lunawood ThermoWood® retains its colour beautifully and does not secrete any resin through the paints or tints. And furthermore, thanks to the resin-free property, the knots don’t show up through paints or tints even over time.

Lunawood ThermoWood® has a characteristic and elegant scent. Scent emerges in heat treatment from natural components of wood, along with other desirable properties. Scent has similarities with other products where heat and aroma are elements, like coffee extracted from roasted coffee beans, smoked foods, BBQ where smoke flavour is important, whiskey and cognac which are aged in flame-treated barrels.

Lunawood ThermoWood® total emissions are significantly lower than untreated softwood. TVOC (Total Volatile Organic Compound) for Thermowood is 0,04 mg/m²h. For comparison, untreated Scot Pine has TVOC of 1 mg/m²h. Emission profile is also different, like scent. Emissions will decrease overtime from their already low levels.

Lunawood ThermoWood® walls, ceilings, floors, or other interior elements naturally soften noise by creating a soft, sound-breaking surface in the space. Echo is reduced on wooden surfaces, which reduces the noise level in the premises. The porous wood surface does not reflect sound in the same way as hard and artificial materials. According to the tests, Lunawood ThermoWood® has 20% shorter reverberation than hard surfaces. When installed battens or Lunawood 3D profiles, the reverberation is even shorter.

Fire rating of Lunawood ThermoWood® products varies due to the design of the profile. Lunawood’s flat tongue & groove cladding products of pine and spruce with a minimum actual thickness of 17 mm have the fire class D rating.

Lunawood provides its tongue&groove products also fire protected to (EN13501) Euroclass B-s1,d0 or B-s2,d0 depending on the profiles. Lunawood Battens can also be fire protected, but the structure needs to be fire tested on case by case basis.

Processing does not affect the unique performance properties of Lunawood ThermoWood®, as it is modified throughout. Planing Lunawood gives its surface a superior quality. Sawing Lunawood is just as easy as sawing ordinary wood. Wear dust mask and eye protection when machining the Lunawood.

Our pine products have heart side as using side due to its better durability (Picture 1). Our spruce products have SAP (sapwood) as using side due to straight grain structure of spruce which reduces de-lamination (Picture 2).

CLADDING:

Lunawood cladding products should always be installed on support battens. Vertical battens (wood or metal) are spaced max. 600 mm centres. In vertical orientation, a double order of support battens is used to provide adequate air ventilation. The ventilation cavity should maintain a consistent minimum thickness of 25 mm to ensure drainage and ventilation. Lunawood ThermoWood® is not recommended to be installed in direct contact with the ground and thus sufficient ground clearance, based on the type of soil, is required. Stainless steel screws/nails are recommended.
The minimum thickness in facade profiles is 19 mm.

DECKING:

Lunawood decking profiles should always be installed on strong substructure. Double row of joists under the end points of the decking boards is recommended. Use spacing/insulation band to ensure capillary break between substructure and decking boards. Joist spacing for 26 mm thick decking boards is 450 mm. For 32 mm or thicker boards maximum joist spacing is 600 mm. The minimum thickness in decking profiles is 26 mm. Use Lunawood Profix hidden fixing to secure invisible fixing and 6mm gap between the boards. End-grain sealant is recommended.

For detailed information on fixings please refer to the Lunawood installation guide:

https://lunawood.com/download-centre

Gluing of Lunawood Thermowood is possible. However, the gluing and compression time may be 4–6 times longer compared to un-modified wood. Good results can be achieved with most common adhesives, but PUR (Polyurethane-reactive adhesives) glue gives the best performance according to test results.

Like all timber products, Lunawood ThermoWood® will go grey upon exposure to UV and moisture, and in time may show some fine cracks or splits on the surface. The graying effect will be visible in a relatively short period of time, 3 to 6 months after installation (see examples below). It is recommended to apply UV-protected and colour pigmented wood coating to help preserve and maintain the original caramel brown colour and appearance.

Read more: https://lunawood.com/story/the-natural-greying-of-lunawood-thermowood-2/

Linseed oil is not suitable for ThermoWood® because it enables fungal growth. Lunawood ThermoWood® will accept most high-quality surface coatings that are suitable for un-modified wood. It can be treated with tinted or pigmented wood oil, wax, wood-protecting stain, varnish or paint – which contains a UV-filter – which helps retain the surface color. The surface treatment can be applied either before or immediately after installation using only a thin coat. When coating, Lunawood ThermoWood® doesn’t require four side treatment. Only weather exposed surfaces might be coated. It is always recommended to seal the cut ends.

Lunawood ThermoWood® is durable and does not require maintenance to withstand time. To keep the original appearance of ThermoWood®, surface treatment is required. The surface treatment should be renewed as necessary. The need for re-coating varies depending on the climate, amount of usage and the degree of exposure to UV-light.

Lunawood ThermoWood® should be carefully transported and stored horizontally in a manner consistent with other high-quality decorative wood materials. Store Lunawood Thermowood horizontally on bearers at least 75 mm off the ground.

Lunawood Thermowood profiles and accessories must be kept clean, dry, under cover and out of the weather. Avoid exposure to UV-light as Lunawood ThermoWood® will turn to silver grey. Store Lunawood in its original packaging or completely and tightly covered under a UV-protective wrap during installation phase to avoid graying of the surface and the formation of shade differences.

Extra care must be taken during handling and installation so as not to damage the factory finish of the boards. Therefore, sorting of the boards should be done with support from both ends or the middle. The same care must be taken during transfer. Lunawood has a uniform color throughout the profile. Even small dents and scratches are not visible, and the surface can be sanded if necessary – and the product still has a beautiful original shade.

Dispose off-cuts in the same manner as untreated wood. Lunawood ThermoWood® can be burned like untreated wood.

Lunawood has FSC and PEFC chain of custody certifications and is sourcing only from certified suppliers. Lunawood uses wood from sustainably managed Nordic forests.