Protecting wood from rot: how do you impregnate wooden posts?

Wooden posts for fences, barriers and for supporting plants have to withstand some environmental influences. Moisture and UV radiation as well as frost pose considerable dangers, as they damage the wood in the long term and can thus lead to rot or accelerated rotting, for example. In order for wooden posts to last as long as possible, they must therefore be appropriately impregnated and protected. We reveal here how it works.

Liquid and putrefaction

Outside, wood is constantly exposed to the elements. The UV radiation from the sun can bleach the natural material and dry it out too much. As a result, it becomes cracked and therefore less stable - but also more vulnerable. Rainwater and other liquids can penetrate the material more easily and cause rot here. Boards and posts will be rotten and can no longer fulfill their function.

The rotting does not always start immediately and visibly. It can also spread from the inside out. The damage is only noticeable when wooden boards and posts are already rotten and possibly entire parts break away. It is particularly damaging if a lot of liquid gets into wooden elements during the frost-free seasons and then freezes in winter. This can severely damage the wood fibers and then decompose more easily. Comprehensive moisture protection is therefore crucial for the service life of wooden elements.

Protect wood

Create distance

The first and often most important step in protecting wooden posts and battens is to create a space between the damp media and the material. If a wooden stake sits directly in the ground, the application of wood preservatives is just like one Glaze or impregnation are not always sufficient to keep the natural material in good shape over the long term protection.

To create a space between wooden posts and the ground or to allow the wood to dry off, the following measures are recommended:

1. Let wood "float"

A slightly raised fence prevents the individual slats from standing up on the ground. A gap of one to two fingers between the lower end of the battens and the earth prevents the wood from constantly coming into contact with moisture. In addition, the material can dry out well ventilated if it has become damp after rain or other precipitation.

Alternatively, you can also use the woods Metal anchors keep from direct contact with the ground. You read these into a concrete foundation and then screw them to the wooden posts.

2. Gravel and co.

If the wooden posts have to stand directly in the ground, it is also possible to fill the excavated hole or the relevant trench with gravel, lava chippings or a similar material. This means that moisture can still get to the woods, but the natural substance can also dry off better and is at least slightly ventilated.

3. Bitumen roofing felt or paint

If there is only little space between the wood and the ground, bitumen roofing felt or a bitumen coating are also possible as protection. These reliably protect against water from the ground and against precipitation. The problem with the paint, however, is that it is perfect diffusion-proof and is therefore not breathable. So with a continuous coat of paint it would come to one Moisture inclusionunder which the posts could rot.

It is therefore advisable to only coat the sections of wooden battens and posts with a bitumen coating that are constantly exposed to wet soil or water. The rest of the wood should be covered with breathable protection. An alternative is the attachment of bitumen roofing felt or bitumen strips, which, however, are also only attached to the sections of wood that are heavily exposed to the weather or moisture.

Glazes, waxes and varnishes

In order to protect wood and wooden posts, glazes, but also waxes and varnishes are often used. The advantage here is that the material can be quickly and easily protected against the ingress of moisture and thus the development of rot. Glaze or another means of choice are applied with a brush or roller. The effort is minimal. However, it can only be used to impregnate the outside of the wooden posts, because the agents only penetrate a few millimeters into the material. However, even minor weak points, such as a crack or a drill hole, create the risk that liquids can penetrate and the wood fibers soak up and rot.

For additional protection from the outside and for light impregnation of the wood against the weather, glaze, wax and varnish are sufficient. However, they have to be a few years apart applied repeatedly as they wear out. In addition, they do not represent any protection from the inside.

tip: Glazes and co. Should not only be selected based on their appearance. An adapted selection according to the type of wood and the stress on the wood is much more advisable. It should also be noted that the purely external application usually does not protect against fungi and insects.

impregnation

If the wooden material is repeatedly damp or even wet and does not have enough time to dry off, a varnish or other coating is simply not enough to protect it. In these cases you should choose appropriate chemical wood preservatives. Another sensible alternative is the use of wooden components that have been pressure-impregnated. This means that posts, boards and battens are also protected from the inside and are much more durable. However, it is assumed that the right choice is made when purchasing. Because wooden elements can no longer be subsequently impregnated as fence laths or posts.

Protection from inside and outside

The best possible way to protect wood from moisture damage and the resulting consequences is to impregnate it from the inside and apply a protective layer from the outside. Boiler pressure-impregnated wood should also be provided with glazes, varnishes or wax in order to achieve the greatest possible protection.