On a low deck where blocking cannot be installed from underneath stretch a string from the house to the outside edge along each outside joint for a reference.
Proper floor joist bracing or blocking.
Another method used to keep the joists from rolling onto their sides is x bracing.
This size is no longer acceptable when framing a structure.
Floor joist bridging is critical to the structural strength of a floor as shown in figure 1.
Whether your home is new or old it is sometimes necessary to install floor joist bracing in order to eliminate squeaking and deflection in the flooring itself.
Cross bracing and solid blocking.
Observe the following guidelines.
Blocking also needs to be provided at the supporting end of a joist.
Bracing will stiffen a floor system prevent floor joists from twisting and increase overall stability however there are actually two types of floor joist bracing commonly used.
Outside joists may not be spaced at 16 oc or may need to adjust to get the proper fit for decking.
That s code around here.
Yet it is not uncommon to find bridging not properly installed or missing all together.
In the past 2x4s or 2x6s were sometimes used as floor joists.
In addition to providing lateral support blocking helps transfer weight to adjacent joists so that the floor acts as a unified system.
Just out of view in that ceiling pic is a rat run or at least that is what i call em.
In buildings with basements the first level of floor joists serves the same purpose.
Blocking is fine too but i like the fact that x bridging is unaffected by cupped joists is much easier to get a tight connection and it actually tightens up as joists shrink.
Floor joists installed on second or third or higher levels double as ceiling joists for the level below.
I use 1x3 pine with 2 medium crown staples to prevent splitting.
Leave outside joists for last and install blocking from underneath.
Ceiling joists i ve never installed solid blocking or bridging before i always install strongback every 8 using a 2x4 flat and a 2x6 on edge.
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.
Establish a permanent deck sheathing fastened to the first 4 feet of joists at the end of the bay or braced end wall.
Building code requires the use of blocking for floor joists that exceed 2 inches in width by 12 inches in depth.
Using 2x lumber for floor joists i install blocking or bridging every 8.
When you build your deck throw the floor joist boards that have gone wild badly twisted or cupped into a separate pile.
Leave the crowned joist and apply sister joists by sandwiching the board with two new joists.
Properly install all blocking hangers rim boards and rim joists at tji joist end supports.
