DIY Slate Roof

Install an underlayment of two layers of felt. The underlayment is not intended to be a waterproofing layer, but is a temporary measure until the slate is installed.

Lay the starter course with the face downward. This method allows the drip edge of the starter course to merge flush with the drip edge of the first face-upward course of slate tiles to give the roof a professional appearance. Lift the starter course on its lower edge with a wood shim to blend it with the other tiles that will be angled on top of other tiles, according to the TraditionalRoofingMagazine website.

Chalk each course of tile on the underlayment, not on the tile, to determine placement.

Overlap each course of tile on the lower edge and inserting the nail into the holes. Do not overnail too far to cause stress on the overlapping tile. The nail should fit snugly into the countersunk depression of the nail hole.

Continue the courses over the surface of the roof, cutting tile as needed at the edges and around flashings to create a neat and secure fit between tiles. Ensure there is at least 3 inches of headlap, or overlap from one course of tiles to another. Increase the headlap slightly as you reach the bottom courses of the roof.

Install copper or stainless steel flashing around chimneys and utility equipment to prevent leakage. Sheet lead can also be used as flashing.

Install saddle ridges at the peaks of the roof. Ridge areas need particular attention. Tiles should not just be left uncovered or simple sealed at ridge points. Saddle ridges use overlapping caps of slate to cover the end tiles. The nail heads are then covered with roofing cement.