Chapter 2 Roof Framing

CHAPTER 2 ROOF FRAMING 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 it’s used to solve some basic construction problems. Next, we’ll 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. TERMINOLOGY LEARNING OBJECTIVE: Upon completing this section, you should be able to identify the types of roofs and define common roof framing terms. 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, we’ll 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 figure 2-1. Gable 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. Hip 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. Intersecting 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. 2-1