I have a steel stud wall with 150mm studs at 600 centres and fire rating of 60/60/60 FRL which we are sheeting with two layers of 16mm fire stop to one side. We have a timber truss penetrating through the wall, how do I go about fire rating the truss. (It's oregon timber).
The truss will have to be isolated from fire from below. It would seem to need fire resistant plasterboard on both sides of the wall, not just one, with the plasterboard continuing along the bottom chord of the truss. It is somewhat similar to Figure 72 in our Technical Design Guide #02 where a fire-rated floor system continues over the top of a fire rated wall. However, we don't have a standard detail for this situation and suggest you seek advice from a fire engineer.
I have what feels like a niche query - we are currently working on a multi-residential project in Hobart and are looking to specify a solid tas oak flooring with an acoustic underlay. The building surveyor has used us to provide a NATA accredited fire report to prove that the critical radiant flux level of the floor build up meets the NCC's Vol.1 clause C2D11 and S7C3. We have been in contact with a local timber supplier who was able to provide a fire report but their report lists the flooring substrate as either concrete, particle board or FC sheet (not a rubber acoustic underlay). I was wondering if by any chance you might have a relevant fire report that might list this? Unfortunately we must have the underlay for acoustic purposes but beyond meeting acoustic requirements are not fixed on the particular product.
Although our fire reports do not include an assessment of timber flooring on a rubber acoustic underlay, our technical department points out that the test for critical radiant flux (CRF) is a surface spread test, so substrates should not be an issue unless there is burn through. Therefore the figures quoted in Table 6 of our Regulatory Information Report 41117.11 would hold good in your case. Note that Tasmanian oak is a trade name for a group of three species which are listed in RIR 41117.11 under their individual names of alpine ash, mountain ash and messmate.
I am preparing to lay a solid tallow wood floor over a yellow tongue structural floor on timber joists. It is 130x19 mm feature grade. My question is - what are my options for managing the expansion of the floor? The space I am concerned about is a wedge shape- the widest part is 12 m wide and the narrow end is about 9.0m I am hoping there is a technique that will avoid the traditional expansion joint every 6m. A project I worked on in the past used sheet metal packers to create small gaps every 4 boards to allow a wider floor without noticeable expansion joints. Thoughts or advice would be much appreciated.
Our Technical Design Guide number 9 provides detailed guidance on the installation of timber floors. A copy can be downloaded free of charge from our website via this link https://www.woodsolutions.com.au/publications. Whether you need an expansion gap at all depends on a number of factors, including initial moisture content of the flooring, local climate, etc. Note the advice in our Guide to the effect that floors are generally more prone to shrinkage in cities with drier internal environments (e.g. Adelaide and Canberra) and more prone to some swelling in warmer more humid cities (e.g. Brisbane) - p. 23. If local experience shows that an expansion gap is warranted, using a metal spacer to leave small gaps is one way to allow for swelling. Perhaps a neater technique is to use cork which compresses if the flooring swells. This topic is also covered in our Guide (p. 37) and cork products are available from specialist suppliers eg. here https://www.ecocork.com.au/other-cork-products/expansion-cork/.
