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,