Cedar roofs are common in Eastern Massachusetts, where I live and work. They're typical of the antique homes around here that date back to the 1700s. Cedar is a premium material, but if you're aiming for authenticity when building a new Cape Cod–style home, that's what you install on top. More-durable western red cedar is the species of choice for roofing; Atlantic white cedar is best reserved for sidewall installation. In this article, I'll explain how I weave the valleys.

I prefer woven over open or butted valleys, both for their aesthetic appeal and because I believe they better resist leaks. While you can approximate the look of a woven valley by cutting and butting the opposing sides together, this still leaves a running seam that can trap wet vegetation and lead to premature deterioration. I close the seam by...

or Register to read the full article.