Are you putting it in the kitchen also? I have the same dilemna. I also have the issue of requiring sound insulation regupol in an apartment and what gets out down first, the kitchen joinery and floor around or joinery on top. I have selected tongue n groove but have a very uneven concrete floor which now need levelling and doubling flooring costs. So check that you have fairly even underfloor for engineered flooring. Agnes

Please put up photos of both.

Parts of Adelaide Hills are bushfire prone so timber may not be the best option. Look at using 'Inex' decking boards as they are a cement based 'decking board'. They can be stained using the same as for timber. Composites are ok in particular 'Modwood' which is of a very good quality. What about tiling over FC sheet that way it's just a regular sweep and a good wash.

Thank you everyone for your input! The existing boards are approx 30 years old, and other than the fact that they appear to be untreated timber, there is no obvious reasons why they have decayed. Hence why I would like to make an informed decision when replacing them so it doesnt happen again (maybe treated pine?). The worst is on the corners of the house which are subject to the most wet weather. But the boards have decay all along the house. Which it seems in turn has allowed insects to attack. We had a building/pest inspection done prior to buying last year, and the report said rot and 'earwig attack' (seems strange?), and there was no evidence of any termite damage/activity. But there is (what I think is) excrement of some sort present. Have attached couole of photos if anyone can identify the excrement? Report also said subfloor ventilation was adequate. However I want to space the new boards/material as far apart as possible to allow good ventilation, while adhearing to fire safety regs. So I will contact the CFA regarding that info as recommended.