Thermowood Decking Maintenance and Care
Lunawood Thermowood decking is an ecological and chemical-free wood material that retains its shape throughout all seasons. With proper surface treatment, the terrace retains its beautiful appearance and remains in good condition for many years. We recommend a regular surface treatment for Thermowood decking when used in applications subject to varying weather conditions. Surface treatment will help to retain the original colour and reduce cracking and splintering that are typical to wood materials over time.
If left untreated, Thermowood will gradually turn gray under the influence of UV radiation and weather. The grey color does not affect the wood’s resistance to decay. Note that clear UV-protective terrace oil without brown pigment, does not prevent natural greying, but slows down the weathering process.
Horizontal surfaces, such as terraces subject to wear and direct weather effects, need suitable protective agents to ensure the mechanical durability of the wood material. In other words, regular surface treatment with terrace oil helps reduce cracking and extends the product’s lifespan.
To preserve the brown tint of the wood, you should treat the terrace immediately after installation using a brown pigmented terrace oil intended for thermally modified wood, such as Tikkurila Valtti Plus -wood oil tinted with Lunawood Brown, TVT 5051 or TVT 5071. Check the correct shades with your paint shop. To retain the correct shade, we recommend repeating the treatment every two years or depending on weather conditions and use of the terrace.
Make sure you also apply the wood oil to all sawn surfaces and extensions.
If you want your decking to grey naturally, you should choose a clear terrace oil. Note that clear oil slows down the natural greying of wood, so the gradual change can take a few years and even longer in shadow.
Lunawood Thermowood can be surface treated to other shades as well, but it should be noted that the color samples tinted to bright wood do not correspond to the final color tone due to the specific characteristic brown tone of Thermowood. We recommend testing the oil in an inconspicuous area.
Basic Maintenance of Thermowood decking
All that is needed to perform basic maintenance of a terrace with Lunawood Thermowood decking during the terrace season is to brush away loose materials and wash with water and a soft brush. Pressure washing is not recommended in order to avoid splintering.
Maintenance with oil
Before oiling, brush away loose materials from the terrace surface. Carefully wash the surface using a deter-gent intended for decking (such as Tikkurilan Tehopesu). Rinse and let the terrace dry thoroughly. Smooth the surface using fine sandpaper, if needed. If the surface has a clear film after washing, remove it before continuing.
Apply 1–2 layers of pigmented terrace oil, such as Tikkurila Valtti Plus -wood oil tinted with Lunawood Brown, TVT 5051 or TVT 5071.
Following surface treatments are also suitable for Lunawood decking profiles:
• Osmo Decking Oil – 010 Thermowood
• Teknos Woodex Aqua Wood Oil – Factory brown
• Owatrol Aquadecks – for instance tones: Honey, Movingui and Teak
• Bona Decking Oil – for instance tone Teak
Follow the instructions for the surface treatment agent. For more information on application and maintenance, contact your local surface treatment supplier for your project.
Greying and Restoring the brown colour of the wood
If left untreated, Thermowood will gradually turn grey over time. Sun, humidity, shadow and other surrounding conditions determine how quickly the wood will grey. Note that Thermowood is a natural wood product, which may have hairline cracks due to the weather, but this does not affect the product’s durability.
If your decking has already turned grey and you want to restore its original colour, you can use a strong washing liquid and/or sanding. After that, the surface can be treated normally, for instance with brown-pigmented oil that helps to maintain the colour. See the instructions under “Maintenance With Oil”.
Black Spots on decking
Impurities in the air such as soot or pollen, or metallic dust can cause small black spots on the surface of the decking. In some cases, a decking base containing sulphate combined with water can colour the wood. Black spots can be prevented by using pigmented decking oil right after installing the terrace.
Black spots can be removed by following these instructions:
1. Wash the surface carefully using a detergent intended for decking. Note that water only won´t remove the black spots.
2. Rinse and allow the terrace dry thoroughly. If the surface has a clear film after washing, remove it before continuing.
3. Smooth the surface using a fine sandpaper if needed.
4. Apply 1–2 layers of pigmented terrace oil, such as Tikkurila Valtti Plus -wood oil, tinted with Lunawood Brown, TVT 5051 or TVT 5071. Follow the instructions for the surface treatment agent.