On the tidewater cottage, the hipped-roof dormers are topped with wood shingles that are overlapped and fantailed in a manner as old as the Virginia colony. The illustration and description below are taken from The Houses of Williamsburg: Construction and Detail (1960), an excellent reference on traditional detail used often in our practice:
"At the hips of a roof, the shingles are 'fantailed"...laid so that those on one side projected about 2 in. above and over those on the other. The choice of which side of the ridge to carry up in this manner was not settled by chance or whim, but with a sound regard for orientation: it had to be the side that received the most prolonged rain. In Virginia, where it was common knowledge that the northeasterly storms were the ones to be feared, the 18th-century builder chose the north or east."On our 21st-century tidewater cottage, the shingles crest to the east, since the heaviest rain hits the farm from the west.