In this chapter, we will introduce you to the
fundamentals of roof design and construction. But,
before discussing roof framing, we will first review
some basic terms and definitions used in roof
construction; we will then discuss the framing square
and learn how its used to solve some basic construction
problems. Next, well examine various types of roofs
and rafters, and techniques for laying out, cutting, and
erecting rafters. We conclude the chapter with a
discussion of the types and parts of roof trusses.
LEARNING OBJECTIVE: Upon completing
this section, you should be able to identify the
types of roofs and define common roof framing
The primary object of a roof in any climate is
protection from the elements. Roof slope and rigidness
are for shedding water and bearing any extra additional
weight. Roofs must also be strong enough to withstand
high winds. In this section, well cover the most
common types of roofs and basic framing terms.
TYPES OF ROOFS
The most commonly used types of pitched roof
construction are the gable, the hip, the intersecting, and
the shed (or lean-to). An example of each is shown in
A gable roof has a ridge at the center and slopes in
two directions. It is the form most commonly used by
the Navy. It is simple in design, economical to construct,
and can be used on any type of structure.
The hip roof has four sloping sides. It is the strongest
type of roof because it is braced by four hip rafters.
These hip rafters run at a 45° angle from each corner of
the building to the ridge. A disadvantage of the hip roof
is that it is more difficult to construct than a gable roof.
The intersecting roof consists of a gable and valley,
or hip and valley. The valley is formed where the two
different sections of the roof meet, generally at a 90°
angle. This type of roof is more complicated than the
Figure 2-1.Most common types of pitched roofs.