Pyramid Holdfasts are supplied filled with concrete. Lip around the base enables building in to bitumen type roofs.
Standard: BS:EN 62561-1, Class H
When choosing a connector it is important to ensure:
- The connector is mechanically robust.
- The connector is selected according to its application.
- The connector is rated for its application.
- To avoid bimetallic corrosion-use a bimetallic connector (do not connect bare copper directly to bare aluminium, or have water run-off from copper, fall into aluminium).
Galvanic corrosion happens when there is a potential difference between dissimilar metals:
- When the materials are in contact in the presence of an electrolyte, corrosion occurs. One metal becomes the anode, the other the cathode. The anode will tend to go into solution and therefore corrode. The electrolyte can be water with impurities from the air.
- In the instance of water run-off from copper- the water carries fine copper corrosion particles which, when they drop on to aluminium or zinc, may result in corrosion. The direct contact of the dissimilar metals are not required for corrosion to occur in such a case.