Cross Members Between Floor Joists

A 2x8 up to 12 feet.

Cross members between floor joists.

What is the proper placement. 2x10 to 15 feet and 2x12 to 18 feet. Blocking is also needed each time the joist overlaps with a center beam and every eight feet between two joists. Proper bridging distributes the load on the floor to other joists and over time prevents floors from sagging and squeaking do to floor joists twisting and warping.

The common spacing between floor joists is 16 inches on center. A joist is a horizontal structural member used in framing to span an open space often between beams that subsequently transfer loads to vertical members. I just watched an episode of ask this old house which dealt with cross bridging between wood floor joists of a house. The cool thing about these however is that the space between cross members is usually big enough to accommodate big pipes even ductwork.

Tom silva explained that the cross bridging transferred the load on the joist to the other joists thus strengthening the floor. How do i keep them even. Be aware that lumber yards have a far greater inventory of floor joists than the home centers or big box stores. The rim joist fig.

Providing more support and rigidity than cross bracing solid blocking is a reasonable alternative but can be an obstacle for running plumbing pipes and electrical wire between floor joists. How far apart are floor joists placed. In general terms joists spaced 16 inches on center can span 1 5 times in feet their depth in inches. When incorporated into a floor framing system joists serve to provide stiffness to the subfloor sheathing allowing it to function as a horizontal diaphragm joists are often doubled or tripled placed side by side where conditions warrant.

If you have central heat and or air conditioning with floor vents it is very easy to remove the vents by pulling them straight up. A lot of questions revolve around joists when it comes to building a deck. With the vent removed you have a wide clear view of a cross section of your floor. Look inside old homes or warehouses and you ll often see funny cross.

This is contrary to my understanding of the purpose of bridging. B the framing member that runs around the perimeter of your house and that the floor joists butt into often gets riddled with large holes. Solid blocking should be used where floor joists overlap over beams. Floor joist bridging is critical to the structural strength of a floor as shown in figure 1.

Building code requires the use of blocking for floor joists that exceed 2 inches in width by 12 inches in depth. Yet it is not uncommon to find bridging not properly installed or missing all together.