The cause of a damp garden wall is often a defective or missing seal. The permanent moisture causes lasting damage to the building structure, the plaster peels off and the wall can become unstable. You can find out in this article what options you have to protect the floor and the top of the wall from this.
How can I effectively seal a garden wall?
To seal a garden wall, you should insulate the foundation with a bitumen sheet or special film and cover the top of the wall with materials such as zinc sheeting, concrete moldings or granite. A horizontal, slightly inclined wall crown also enables good water drainage.
Properly seal the garden wall before construction
In the case of a garden wall, both the foundation and the top of the wall should be protected from water penetrating:
- Therefore, insert sealing material below the first row of stones. This prevents water from rising from the ground into the wall.
- According to DIN 1053, a horizontal, slightly inclined wall border above the top of the wall ensures that rain and meltwater drain well and cannot press into the masonry from above.
Seal the foundation
Always build a foundation for the wall so that it does not stand on the natural ground. Otherwise, the moisture from the ground could rise from below into the masonry and capillary upwards.
An additional horizontal seal is applied downwards to the foundation, for example in the form of a bitumen membrane or special film.
Properly cover the wall crown
Plastering offers no protection against water penetration. Therefore, the top of the wall must be covered with a suitable material.
- Zinc sheeting is the simplest solution. However, for walls that exceed a certain length, the sheets must be soft-soldered and thus securely connected to each other.
- Concrete moldings or in-situ concrete of sufficient thickness are suitable as a cover. Make sure that the individual parts protrude far enough over the garden wall and have enough of an inclination so that the water runs off.
- Granite is relatively expensive, but gives the wall a very elegant look. When applying, a good seal must be made with sealing slurries. If you would like to add a granite finish to a natural stone wall, the cover should be laid on the crown with natural stone mortar and elastically jointed. Since these walls “work”, it is ensured that the top of the wall lies solidly on the small structure.
Tip
If you decide to use bitumen cardboard, in order to seal the wall against rising damp, it must be flamed. For this you need bitumen vapor barrier membranes (€105.00 on Amazon) and bitumen primer as well as a flame hammer, which you can borrow from many hardware stores.
