I have walked on my roof and the tiles are cracking, are the tiles on my roof faulty?

The short answer is that you should not be walking on your roof tiles! Apart from the damage you can cause to the roof, think of the health and safety risks involved.

Roof tiles and slates are not designed to be walked on, so if they are cracking or breaking when walked on this is not likely to be due to faulty tiles or slates. Generally, tiles and slates must be strong enough to withstand all the handling and transportation between the factory and your roof, as well as being resistant to the weather once they are laid on the roof. But if you do need access over the roof, for whatever the reason, you should make adequate provision to both stay safe and to protect the roof covering. This can be in the form of roof ladders or crawling boards, safely anchored to prevent slipping and with some form of packing over the tiles.