Painting bitumen on wood - does that make sense?


To protect wood from moisture, it is often thought to protect it with bitumen. Whether bitumen coatings or bituminous coatings are advisable to protect against moisture, and what you should think about, read in this post.

Bitumen paintings on wood

On many occasions you want to protect wood very effectively against moisture and seal thoroughly. The caulking ability of bitumen seems to be a good solution for:

  • the inside of flower troughs
  • wooden posts
  • Wood that is exposed to permanent moisture

In principle, it is also possible to seal wood with bituminous coatings. As a substrate for a coating wood is basically suitable.

The problem lies in the fact that bituminous coatings are completely diffusion-tight. Moisture in the wood would be trapped and could not escape. This would make the wood rot. In addition, this coating would actually have to be completely leakproof at all points so that water does not penetrate anywhere. Any moisture would be trapped in the wood and it would start to rot. In practice, this is unrealistic.

Better alternatives

Professional wood protection is definitely a better alternative than bitumen coatings. Under certain circumstances, they can be used on a point-by-point basis (for example, in the border area between the air and the ground at the posts) - but ordinary wood protection measures are usually sufficient here as well.

Bitumen coverings on wood

Bitumen strips are often used as so-called drainage protection in wood.

For example, support beams of plank flooring are sealed with special elastomeric bitumen strips to protect the wood surface from leaking water. Between the strips there is a polyester insert.

It can also be used to seal the gap between planks and stringers and prevent moisture from accumulating there that could penetrate the stringers. The bonding of such seals on wood is certainly a sensible and harmless measure (in contrast to continuous bituminous coatings on wood).

Tips & Tricks

The carbolineum (coal tar) used to protect wood parts from massive moisture has been banned in Germany for many years. It is irritating to the skin and carcinogenic. As a coating, it has always worked outstandingly, no wood preservative protects as effectively as tar oils. The high health risk is not worth the effort.


Video Board: How to remove black tar adhesive from a concrete floor