A quick look through any 19th Century suburb will convince you that many other roof forms are possible in addition to those discussed last month in Part I. The gambrel roof, which involves setting a shallow-pitched gable on a steeply pitched lower roof, can be used to solve second-floor space problems. It is an ingenious solution, since it alleviates the thrust problems noted in last month's column. The thrust from the upper roof is taken out at the break in the roof by horizontal ties, and the lower roof adds little thrust of its own. Properly done, a gambrel can be quite handsome—but it all hinges on proper dimensions and details. Most gambrels are improperly constructed,
