Critical Task: 051-236-1141
In this lesson you will learn how to perform one task-construct a floor.
TERMINAL LEARNING OBJECTIVE:
You will describe the construction of a floor system.
You will be given the material contained in this lesson.
You will correctly answer the practice exercise questions at the end of this lesson.
The material contained in this lesson was derived from FM 5-426.
After the foundation is in place, you are ready to start constructing the framework for the floor system.
1-1. Types of Sills. Sills are the horizontal timbers of a building which either rest up the masonry
foundations or, in the absence of such, form the foundations. The sill is the foundation that supports all
of the building above it. It is the first part of the building to be set in place and rest directly on the
foundation, posts, or the ground. Sills are joined at the corners and spliced when necessary. The type
of sill used depends on the type of construction used in the frame.
a. Box Sills. Figure 1-1, page 1-2, shows box sills. Box sills are often used with the common
style of platform framing (either with or without a sill plate). With this type of ill, the part that lies on
the foundation wall or ground is called the sill plate. The sill is laid edgewise on the outside edge of the