01
Layout terms
Exposure is the visible height of a slate course. Headlap is the overlap created by the slate two courses above. Side lap and joint offset describe the horizontal relationship between joints. A roofing square is 100 square feet of roof area, not 100 pieces of slate.
02
Detail terms
The starter or under-eave course begins the double-lapped system. Cant lifts the lower courses into the correct plane. A cricket or saddle diverts water around an obstruction. Step flashing, counterflashing, valley lining, ridge and hip treatments complete transitions.
03
Repair terms
A slate ripper removes concealed fasteners. A bib is a concealed metal flashing used with certain repair methods. A slate hook can support an individual replacement. Salvage means serviceable existing slate retained for reuse; it does not mean every removed piece is automatically sound.