How to protect exterior wooden surfaces for a long-lasting durability

Wood, as a natural organic material, is exposed to degradation processes in outdoor products caused by non-living and living factors. Precipitation, water, high temperature fluctuations and UV sunlight cause alternating shrinkage and swelling of wood and relatively slow damage to wood, which can become visible only after a few years in the form of colour changes, cracks and relief structure of the wood surface.

Wood products can be protected against these degradation factors for a long time with various surface coatings. Indirectly, coatings also protect wood from wood fungi and insects, which cause more pronounced and faster changes in the wood and can destroy it in just a few months.


Preventive natural protection measures begin at the planning of the facility. With the right construction solutions, we can ensure that the wood remains permanently dry. Air-dried wood is completely safe from infection by all types of wood fungi and insect attacks.

Unfortunately, we cannot always provide such conditions that the wood is constantly dry. Various fences, window frames, external formwork, and especially wood in contact with the ground (pillars, poles, thresholds), represent favourable conditions for wood pests.

Therefore, in such cases, it is necessary to preventively protect wood products before installation with chemical preparations containing biocidal components – fungicides and insecticides.

The most effective preventive protection of wood is achieved by the process of deep impregnation in boilers, which is carried out at impregnation stations. Since such a method of protection is demanding and tied to a specific location, it makes sense to use simpler, but still sufficiently effective surface protection procedures. These are mainly coating, spraying or dipping. Of these three procedures, coating and spraying impregnating biocidal products are the simplest, but also slightly less effective than dipping, especially if it takes longer (a few minutes or even hours).

The advantage of further surface protection with coatings is that it covers the entire surface of the wood and thus prevents the leaching of biocidal components from the wood, and at the same time the product is also aesthetically enriched.

From our many years of experience, we advise that surface protection be carried out on suitably dried wood in finished elements or products. The impregnating agent with biocides will penetrate the wood and effectively prevent all surfaces, including possible cracks. If we coat or. we inject elements of fresh wood, which later cracks, then the protective layer is broken locally. The protection of the wood will be poorer in this case, as deeper cracks in the wood can infect unprotected wood with fungal spores or lay the eggs of wood insects.

Which products to choose for protection

To protect wood against insects and fungi, we offer Lazurind base and Aquavita impregnant extra. Lazurind base is based on solvents, and Aquavita impregnant extra is water-based. For the treatment of windows where protection against insects is not required, we recommend the use of Aquavita impregnant dip & brush, which protects the wood well against blueing and rotting. After drying, transparent and top coatings based on solvents or water can be applied over all products to prevent the smooth penetration of water into the wood and to protect surfaces.