Coating and Maintenance of Cladding

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Coating and Maintenance of Cladding

UNTREATED THERMOWOOD

Thermowood is incredibly durable and can last for years without any protective coating. However, exposure to weather and UV rays naturally changes its color—from a deep brown to a soft, silvery gray. This transformation happens gradually and varies based on the environment and architecture, shifting from light silver to almost black. Over time, the surface may develop rougher fibers and small cracks, which can make it more prone to surface mold.

COATING

A semi-transparent outdoor oil, wax, or stain with pigment helps protect Thermowood from UV rays while keeping its natural look. Most people go for finishes that either enhance its original caramel tone or blend with the natural graying process. This is a smart choice because, as the pigment gradually fades over time, the exposed wood starts to gray, creating a smooth, even transition that still looks great. If you prefer, you can also use opaque paints or stains to achieve a different color. Whatever you choose, it’s important that the coating lets the wood “breathe” and doesn’t trap moisture.

The boards can be pre-coated at the factory, or you can paint them yourself before installation. If you’re joining boards lengthwise, don’t forget to coat the ends too—this seals the cut fibers, preventing water from seeping in and causing discoloration. When applying any coating, make sure the wood is clean and dry. And as always, follow the manufacturer’s instructions for the best results.

MAINTENANCE

COATED:

Refresh the surface as needed, depending on the type of product, how much mechanical friction it gets, and sun exposure. In general, the more pigment in the finish, the longer it will last without needing maintenance. Since Thermowood has no resin or tar, coatings stick better and last longer on its smooth, clean surface. No need for sanding—just wash it with an alkaline wood cleaner, rinse with water, and apply a new coat of stain.

UNTREATED:

Untreated Thermowood ages naturally and doesn’t need any special upkeep. However, if needed, you can occasionally wash the surface with a special wood soap to remove dirt and surface mold.