When attendees at the JLC Live expos see the schedule in front of my demonstration clinic, they come up and ask, "Why would anyone want to shingle a roof backwards?" While it may seem counterintuitive, top-down roofing makes sense in a number of situations. In the last couple of years, I've found myself using it more frequently than shingling from the bottom up. When I say top-down, I don't actually mean applying each course of asphalt shingles in reverse direction starting at the ridge. I do top-down roofing in lifts, or groups of courses, from 4 to 7 feet high, starting near the ridge.
In new construction, I choose top-down roofing in two instances: when I'm concerned about scuffing up the shingles, and on steep roofs when it's necessary to work from roof staging. The technique also works well for reroofs (see "Top-Down Great for Reroofs," below).
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