havabeer

the only thing i can see that is special is that they have a switch on them that lets you run them at: low med high humidity other then that probably paying for a brand name and possibly the fact I think they're still made in australia rather then china?

you can buy the eco fans from bunnings https://www.bunnings.com.au/search/products?q=ecofan&sort=BoostOrder&page=1 I think the prices have gone up since I bought them as per my thread here https://www.renovateforum.com/f198/more-sunlight-subfloor-129739/

take the CFM of your fan and halve it and you're probably getting close to the real CFM of what its actually moving, add flexible duct work and louvers blocking the outlet and it goes down even more. that it a shoddy duct work job, the tape doesn't look like proper duct tape either with patches of it. What does it look like in the roof if he hasn't extended it all the way in the cupboard?

can you just paint the outside?

yeah just glue some non slip edging or even some thin aluminium angle there.

yep, buy a big bucket of exterior grade water proofing or bitchumen paint and a heap of rolls of the bandage stuff that should be next to it and just goto town on the whole thing.

yep, time to get the sander back and get it all back to fresh wood. what grit did you take it to if you only did 1 pass? also find a timber floor sanding supplier and get a quality 2 pack polyurethane instead of the Cabot's stuff from the big green shed.

we had a similar problem with a crack. a plastic expansion joint can be installed to stop the cracking

did you try the pre cast concrete place at teralba? I can't imagine many place having them on the shelfs due to the size and weight of them