01
Plan the layout before fastening
Slate length, exposure and headlap determine course spacing. The roof dimensions, eave detail, top-course conditions and penetrations should be planned before field installation advances. Random adjustments can create short headlap or visually uneven courses.
02
Support and fasten without stressing the stone
The deck and substrate must suit the specified system. Fasteners should hold the slate without pinning it tightly or punching through the face. Pieces should lie naturally without rocking. Thickness sorting helps keep courses stable and visually consistent.
03
Treat flashings as part of the roof
Valleys, chimneys, walls, penetrations, hips, ridges and eaves must be detailed with compatible, durable materials. Underlayment is temporary protection and secondary defense; it does not correct inadequate slate laps or flashing geometry.