A traditional plumbing and roofing technique where sheet lead is shaped around a corner or angle by beating it with a wooden bossing mallet. The process stretches and gathers the metal without cutting it, ensuring a continuous, watertight corner without the need for soldering or leaving a vulnerable hole.
Heard on the job
You need to boss up that corner properly so the flashing doesn't leak behind the chimney.
Also heard as
- bossing