JCU Research Reports

Some people in this forum may be interested in these reports. Mainly applicable to small scale residental and cyclonic effects.

http://eng1.jcu.edu.au/cts/research_reports.htm

 

[rowingengineer]

Be careful with these reports especially the truss tie down reports. They are only applicable to the set dimensions of the products used. For instance, they have tested 120 mm pine truss end instead of 90 mm (which is the common size). the overhang is present in all tests, this is not true for all installations, ie to a parapet wall. The support apparatus used is steel, not timber, causes problems with double bending in the steel test rig. The tests didn’t include any account for horizontal load. I could go on, but I am sure everyone gets the idea.

An expert is a man who has made all the mistakes which can be made in a very narrow field

 

[hokie66]

Thanks for posting them, OzEng. I scanned through the one on the 2008 Gap storm in Brisbane, and found it interesting. So many of the problems, even in the newer houses, were caused by poor workmanship. Of course, when a big tree falls on your house, you can't blame the carpenter.

 

[rscassar]

Thats why engineers need to take a firm stance when we see poor workmanship onsite. I found a good report from JCU regarding testing done on gyprock ceilings used as horizontal diaphragms.

 

[hokie66]

In single family dwelling construction, how much engineering involvement is typical in Queensland? I haven't kept up with the situation in house construction, but my impression was that engineers don't have a big role, and rather that most of the design is left to drafters, and the inspection to "certifiers".

 

[OzEng80]

hokie - depends on the budget. 'Building Designers' generally draft & design class 1 structures for your typical domestic housing then get an RPEQ (registered professional engineer Queensland) to certify the design. There is a 'form 15' (design certificate) requirement for all building applications in QLD. This currently, needs to be endorsed by an RPEQ - though designers may be able to certify 'deemed-to-comply' designs (ie to AS1684&2870)- I am not 100% on these limits. The RPEQ certifications are generally covered by 'one-man-band' type operations who offer a couple of drawings of standard notes and get paid peanuts for their risk.

The higher end housing of which I have some involvement ($1M+) tends to follow traditional means ie documented by an architect and a consultant team.

Similar to the ‘form 15’ a ‘form 16’ (construction certificate) needs to be lodged at the end of the project to endorse the construction. There are limits on this as well as to who is able to endorse this certificate (though not as onerous as the form 16).

So in summary - yes engineers are supposed to have more involvement than down south (I assume – I don’t actually know?) for single family dwelling design, but given the lack of fees available most houses get a cursory review at best before being stamped.

 

[OzEng80]

Hokie - Engineers Australia article on RPEQ's FYI.

 

[hokie66]

Thanks, OzEng. Yes, I've been an RPEQ for many years, but my work has been mostly in commercial and industrial structures. In housing, my understanding has been that much of the design is covered under the "prescriptive standard" provisions and thus does not require an RPEQ, unless the local authority has other rules such as for footing design and structural design in cyclonic areas.

 

[rscassar]

How about buildings other than houses (say institutional buildings) and design and construct items (such as timber roof trusses). Is anybody prepared to accept a form 15 from a non-engineer for these items keeping in mind their is no prescriptive code for the design of timber roof trusses like their is for other building elements for class 1 & 10 buildings as prescribed in AS1684.

Please comment.