When you build your deck throw the floor joist boards that have gone wild badly twisted or cupped into a separate pile.
Proper floor joist bracing or blocking.
Cross bracing and solid blocking.
Floor joist bridging is critical to the structural strength of a floor as shown in figure 1.
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.
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.
Another method used to keep the joists from rolling onto their sides is x bracing.
In the past 2x4s or 2x6s were sometimes used as floor joists.
Blocking also needs to be provided at the supporting end of a joist.
Outside joists may not be spaced at 16 oc or may need to adjust to get the proper fit for decking.
Just out of view in that ceiling pic is a rat run or at least that is what i call em.
I use 1x3 pine with 2 medium crown staples to prevent splitting.
Properly install all blocking hangers rim boards and rim joists at tji joist end supports.
Leave the crowned joist and apply sister joists by sandwiching the board with two new joists.
In addition to providing lateral support blocking helps transfer weight to adjacent joists so that the floor acts as a unified system.
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.
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.
Observe the following guidelines.
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.
Building code requires the use of blocking for floor joists that exceed 2 inches in width by 12 inches in depth.
Lack of proper bracing during construction can result in serious accidents.
Later cutting this crooked lumber into short blocking makes good use of boards that would otherwise have to returned or scrapped.
Yet it is not uncommon to find bridging not properly installed or missing all together.
That s code around here.
Make sure your joists are spaced correctly deck joist spacing should never exceed 16 on center with the exception of max deck boards which allow for maximum 24 on center.
Leave outside joists for last and install blocking from underneath.
This size is no longer acceptable when framing a structure.
In buildings with basements the first level of floor joists serves the same purpose.
Using 2x lumber for floor joists i install blocking or bridging every 8.
