Max height of internal masonry walls (AS 4773.1)

[mj24]

Looking at the Australian residential masonry code (AS 4773.1), at the section on single leaf, unreinforced walls. The requirements for internal walls seem quite vague, giving only a maximum height for different brick thicknesses:

"Internal single-leaf masonry walls shall be at least supported at the top in accordance with Clause 6.4 and shall be dimensioned in accordance with Table 9.3"

The table states that 90mm thick masonry can only be a maximum of 2400mm high, whereas an external screen wall can be up to 3000mm high. I would have thought that an internal wall supporting a concrete slab would be able to be used for 3000mm panels, and I am sure that it is done regularly.

Does anyone know the basis for this requirement, and do you adhere to this?

 

[charliealphabravo]

If you are using a rational engineered design method based on the technical codes then I don't see how there could be a limit. At some point you may need reinforced bond beams/mullions/braces/tie columns, etc. If you are looking at a prescriptive method (such as in many residential codes) then you are stuck with the limitations.

The base building codes usually steer away from blanket limitations on rational design and defer to the technical standards. The solution is not to use prescriptive codes in this case. The enabling/disabling language is usually in the administrative portion of the residential building code (ie page 1). The IBC/RBC says something to the effect that it is not intended to prevent engineered design according to the technical standards (very poor paraphrase from memory). I have a statement in my general notes which says: "Design is in accordance with engineered design, empirical design, or conventional construction methods as permitted by the Code."

Having said all that, I do not have the code you reference. But since it is a residential code I'm pretty sure I'm on target.