Bridging Floor Framing

Bridging holds the joists in line and helps distribute the load carried by the floor unit.

Bridging floor framing. Draw up a basic floor framing plan. Bridging between joists floor plans or specifications usually call for bridging between joists. Your sketch should depict the floor s basic shape and layout complete with any additional features like alcoves nooks and staircases. Extremely long spans staircases or interior walls typically require additional support which can complicate your framing.

Floor joists are typically 2 by 8s 2 by 10s or 2 by 12s. Before you begin cutting or measuring grab a pencil and paper and sketch an outline of your floor. Floor joist bridging is critical to the structural strength of a floor as shown in figure 1. If the china cabinet in the next room rattles as you walk across the floor try stiffening that floor fast with inexpensive metal braces called bridging bridging allows each joist to share weight with its neighbors and can cut deflection how much the joists flex by half.

A floor s framework is made up mostly of wooden joists that run parallel to one another at regular intervals. So the floor deflection under the piano leg is much less if four or five joists are bridged together to share the load than if bridging has been left out and one joist has to carry the whole load. Floor joist bridging vs blocking i like laying 1 1 8 super flat easy to pound t g together dropping a 2x6 from a floor above doesn t put a hole in it. Section r502 10 of the international residential code states that header joists can be the same size as the floor joists when the header joist span isn t greater than 4 feet but if the header joist span is more than 4 feet you ll need to double the header joist and ensure that it s capable of.

Figure 1 25 shows the lapped view a and butt view b methods of framing over girders. Nail bridging on all joists. This goes a long way in making sure the framing is firm and the flooring is secure. Some newer homes have manufactured i beam shaped joists.

Blocking is also needed each time the joist overlaps with a center beam and every eight feet between two joists. Figure 1 25 joists supported by s beam using wooden blocks. Cross bracing or bridging. Ceiling joists are usually 2 by 6s or sometimes 2 by 4s if it is an older home.

The weight of the piano is centered over a single joist but the bridging transfers some of the weight to the adjacent joists. Additional support for the floor joists is achieved by nailing the ends of the joists into headers.