A. Martin Obando responds: You can make slight bends in shingles by just soaking them. But for serious curves, you’ve got to steam them. Get a book on wooden boat building or visit a boatyard if you want to learn how to steam wood — the same techniques that work for big timbers work for shingles. I’ve seen people rig up a steaming apparatus from an old beer keg, a piece of waste pipe, and a propane heater — if you’re handy, it’s not too hard.

Ten or 15 minutes of steaming will soften up shingles. Once they’re soft and you’ve bent them into the shape you want, douse them with cold water and they’ll hold that form.

or Register to read the full article.