Rectangular roofing slates have the same format as scalloped slates, but differ in shape and give a cleaner look. The rectangular slate has straight sides and is laid in a rectangular pattern. A slate roof with rectangular slates needs more overlap, and is therefore heavier than a slate roof with square slates. A rectangular slate roof also requires more slate than a roof with square slates.
Slate roofs with rectangular slates come with gable slates and strips for eaves and ridge. Every other course ends with a standard slate and every other with a gable slate. The gable slate is 1.5 times the width of a standard slate. The eaves slate mounted along the gutter is twice as long as the width of a standard slate.
