1. What can appear on slate surfaces?
Immediately after the laying the membranes, especially in very hot weather, oily marks can appear on slate surfaces due to the natural bitumen mass migration. Such marks usually disappear after rainfall which effectively washes the surface. If these marks should persist it is possible to wash the surface with a medium pressure hose, taking care to avoid aiming the water at the end laps (to avoid accidental peeling). However it should be remembered these marks do not affect the product’s efficiency in any way.
2. What is it necessary to periodically check for on the membrane surface?
As previously stated, it is perfectly normal that a certain percentage of granulated mineral is lost. However it is necessary to check that this granule loss does not block up overflow systems on the covering. Furthermore it is important to check that the bitumen mass is not directly exposed to sunlight. If the granules should thin out over time it is possible to paint the affected area with an appropriate paint.
3. What is it necessary to periodically check for on an unfinished granule covering?
In the case of an unfinished granule covering it is necessary to periodically check the overlap seal, particularly in the most stressed parts (corners or expansion joints of the building). Over a period of time some overlaps may come unstuck for various reasons; for example a small amount of water may not cause immediate seepage but could, due to overnight frost, cause eventual lap peeling and lead to seepage.
4. Is lap peeling normal?
ATTENTION: Lap peeling over time is normal as the covering is applied in segments and this is why periodical maintenance is necessary.
5. Do I have to check that vents are clear?
It is necessary to check the working order of all ventilation systems. The vents should be dust free and free from obstructions such as wasps nests etc.
6. What do I need to check?
Check the cleanliness of the overflow pipes.