Issue 37 – April 2012
Where a lower-level framed wall supports joists and a framed wall above, there needs to be a physical connection between the upper and lower frames.
However, determining the specific requirements is not easy as the relevant information is spread throughout NZS 3604:2011. To attempt to unravel the requirements:
- use Table 8.19 for lower-floor framing stud to top plate connections
- use Table 7.5 for intermediate-floor joist to lower-floor wall framing top plate connections
- use Table 8.19 for upper-floor wall framing bottom plate to intermediate-floor joist connections.
In essence, no straps are required to the above connections except where there are windows within the upper level framing. This triggers the lintel fixing requirements of Table 8.14 (lintel fixings).
Where lintel fixings are required by Table 8.14, the specifics are given in Figure 8.12 (for example, having the trimming stud strapped to the floor joist and the lintel strapped to the trimming stud).
Note that, where the wall incorporates a proprietary bracing system such as plasterboard sheets, their specific fixing and holding-down requirements need to be incorporated. This may include the use of strapping or alternative fixing requirements for studs and bottom plates.
Summarised from BRANZ Guideline newsletter, March 2012