The truth about slate roofs.
Strengths & Weaknesses
Slate roofs are the most durable longest lasting roofs in the world. They shed snow loads and are resistant to weathering and the wear and tear of the elements and heat. Having said that lets discuss some issues such as wind driven rain and underlayments. Today we have modern ice and water shields and even high temp ice and water shields. These are extremely well suited for use under modern roofs. These ice and water shields protect against water that can be pushed back into the slate or flashing and are extremely beneficial. Older slate roofs do not have this benefit. There was no such ice and water barriers available when these roofs were put on. So older slate roofing systems can experience leaks in heavy wind driven rain events. This can be remedied by the removal of slate and installation of a modern ice and water shield however this is usually cost prohibitive. Modern underlayments have changed the game and are a really effective material when used in conjunction with slate roof systems.