Why did you assume that? Did you not get a detailed quote & a signed contract specifying exactly what he was going to do?
He did give me a detailed quote and he told me they were going to lay a screed on top of everything (half of the space is concrete and half was floorboards).
Ply wouldn’t be my choice over a wet UFH system but it depends how it’s done. Frankly, I’m always very suspicious of plumbers doing tiling!
He is not doing the tiling, I will get a tiler to do that. He was just going to leave a screed or something that I can get someone else to lay the tiles on. He is not even doing the screed, he is subcontracting a builder to do that work.
Yes, & differential movement of the ply will be a major factor; it’s not ideal.
So what can I put there?
If it’s not done correctly using the correct materials, yes.
So are there any materials that would make it ok even with the ply?
Tiling over UFH of any sort is a little more involved & suspended timber floors need additional consideration/prep & the tiling materials aren’t cheap. A between joist screed overlaid with a cement backer board would be ideal with a wet system but if you didn't get a spec, don’t have a fixed price & he’s charging materials + time, you could be in for a shock either way. Alternatively, if he’s skimping, you could end up with something that will fail fairly quickly.
He didn't mention any price change yet, even though he is running a bit late now.
He seems a very nice guy, I don't expect any nasty surprises. If something else needs to be done, I would rather get it done properly. So should I ask him to screen over the joists anyway, despite his recommendation for the ply layer?
Personally, I think Trav is poor choice for any floor for many reasons + it can be high maintenance but it rather depends on quality, how it’s laid & how it’s finished off.
Before you go any further, I think you need to ask you “plumber” for a detailed spec of the prep he will do & materials he intends using & post it here for comment.
I don't know much about tiles, I just loved the look and feel of the travertine. I thought that with a very good feeler/seal it will be just as good as ceramic or porcelain, or at least so I was told at the shop.
I went back to check the quote and it doesn't mention the building work, just the plumbing items. I guess I missed that at the time, but I am sure he confirmed it all verbally. Besides, his builder did already put in a lot of effort as he had to take out a couple inches of the previous screed in half of the area.
Thank you for your comments. Can you please advise me further?