Installing a slate roof requires special knowledge and skills, but if you follow a few basic rules and avoid common mistakes, a slate roof can be done by a nonprofessional too.
General Labor Practices
Do not step on the tiles during installation. Always work with roof ladders and roof scaffolding. This is to avoid slipping of the plate, eg. Broken or fallen panels after installation. Place each layer in a permanent chalk line on the roof surface. Don’t put chalk on the tile itself.
The line marks the top edge of the panel. Measure from the underside of the roof where you need to place your line to ensure accuracy and consistency. Don’t lay the slates without chalk lines as you can easily lose your headlap and ruin the roof. For professional consultation and help, you can ask for a free, no-obligation quote from various roofing companies.
The starter course is one of the most important courses on a slate roof and you must install it correctly. First, nail a wooden or copper cant or shim under the bottom edge of the starter course. This will tilt the starter course so that it is at the same angle as all other slates. Then install the starter course with the slate face down and the backup. The starter course is the only course that is installed this way. All other slates are installed with the face-up, exposing the beveled edges.
Install the starter course and the first course of field slates at the same time. Do not run the starter course ahead of the first course unless your starter slates are the same width as the field slates and only have nail holes on the top edge. This way you will have correct side laps and ensured that no nail holes in the starter slates in the joint between the first course slates can create a leak.