How to Sheath Floor Trusses

Sometimes trusses are used as floor joists in floor systems. The difference between a joist and a truss is that a joist is a solid piece of wood seated on its narrow side to provide rigidity for a subfloor. In flooring, a truss is a wooden framework that, when viewed from the side, looks like a series of triangles sandwiched between horizontal slats of lumber. Despite the differences between these two floor supports, sheathing a truss is similar to sheathing a joist.

C-D grade plywood
1½ inch wood screws
Drill
T-square
Circular saw
Protective eyeglasses

Instructions

- 1
  Center a C-D grade plywood panel over the center truss, with the grain of the plywood running perpendicular to the trusses and the C side up. This panel is properly placed when it is laying in the approximate center of the room with each end of the panel centered over a truss.
- 2
  Screw the panel into the trusses with 1½-inch wood screws. Use a drill to insert screws every 6 inches along the ends of the panel and every 12 inches throughout the center of the panel.
- 3
  Lay down subsequent panels on trusses surrounding the panel you started with. Stagger the panels in each course so that the panels appear to stair-step across the floor of the room, the way bricks stair-step across a wall. Leave a gap of 1/8 inch between panels to allow for expansion. Screw the panels into the trusses following the same procedure in Step 2.
- 4
  Cut the panels to fit the outer limits of the room if full-sized panels do not fit in the remaining space. Use a circular saw to cut the panels into the space available.

What Do Wood Floor Trusses Have Built-in to Level the Floor?

The Best DIY Concrete Coatings

Floors