01
Select for the actual slate
Hook length must support the replacement tail while the shank reaches an adequate attachment point. Gauge and metal should suit slate weight, exposure and the surrounding flashing metals.
02
Place without lifting the course
The hook should hold the slate securely without creating a high point that opens adjacent laps. The replacement must maintain the original course exposure and joint relationships.
03
Distinguish repair hooks from hook systems
Some roofs are designed with hooks throughout; others use hooks only for isolated repairs. Whole-roof systems need product-specific engineering and layout rather than a repair technique repeated without design.