Lead Joints

1. Drip, formed where lead is lapped over a step in the substrate.
2. Hollow roll, is formed when two sheets meet to form a standing seam which is turned into a roll. (Illustration 1), (Illustration 2)
3. Lap, where one sheet is simply lapped over the other.
4. Welt, formed by turning the undercloak up by approx one inch, and the overcloak by two inches, which is then folded over and lightly pressed flat.
5. Wood roll, formed by dressing the edges of adjoining sheets over a wood core (Illustration).