The massive use of slate in previous years was determined by its affordable price and durability. There are still many houses covered with this popular material for low-maintenance roofs. However, minor repairs still need to be done, as over time, cracks and even holes appear on the surface. Those who, for various reasons, cannot separate from the cement and asbestos coating, make repairs with improvised materials. Let’s see how this happens in practice.
Why cracks appear
With all its remarkable advantages, slate maintains a low resistance to mechanical stress. Although the coating tolerates ultraviolet sunlight and increased humidity enough, its long-term exposure weakens the original resistance. Over time, the structure of the material becomes more vulnerable and, with sudden changes in temperature or when the branches fall, longitudinal or transverse cracks appear on the leaves. The wind load, the pressure of the winter snow layers, also affects, which is why the strong crest of the wave begins to break, exposing the heads of the nails. If the defects that appear are not repaired, they will gradually expand. In case of slate roof repair this is important.
Obviously, it is better to replace the damaged coating completely. But if that is not possible, minor repairs will become the only way to eliminate leaks and protect the structure from destructive moisture.
Maintenance extends the life of the roof
In addition to knowing the process of repairing a slate roof, you need to understand how not to bring the roof to a deplorable state. Even the careless movement on the roof during pipe cleaning and repair work can lead to the appearance of new cracks under the weight of the master. Therefore, it is necessary to place special wooden floors on the roof so that the transverse slats that hold the boards underneath are located in the recess of the slate wave. This allows the load to be evenly distributed throughout the coverage area. On the steep slopes of the roof, for work, there must be a ladder with a length equal to the total slope of the roof, with a hook on the ridge.
A chronic disease of slate roofs – colonies of mosses and lichens, especially in shaded areas. If the vegetation has already captured the deepening of the wave, it will retain the flow of water and the growing moss will start to lift the leaf joints, making way for the rain moisture. Any vegetation on the slate creates conditions for the formation of new cracks.
A simple and effective way to deal with mosses and lichens is to regularly paint the rough surface of the slate with several layers of durable atmospheric paint. Cleaning the old green carpet roof can be done mechanically and then treated with a preparation that destroys the colony’s root system.
It is necessary to inspect the attic roof at least twice a year. In the presence of an insulating undercoat, cracks are more difficult to detect, but an audit is mandatory. Otherwise, mold stains will soon appear in places with leaks, which will be transferred to wooden structures.
How to seal cracks
Longitudinal cracks along the crest or in the deepening of a wave can be repaired with a waterproof self-adhesive butyl rubber tape, specially designed for slate. Install it outside and inside the cracks or just outside. If you install the tape only from above, it is best to install a strip of galvanized sheet under it, which must receive a waveform in advance. Then the movement of the crack will not affect the integrity of the tape.