Bathroom fitter - seems unsure of what he's doing...

[CheerioHunter]

Hi all.

Looking for some advice please.
We've been up concerned for the past two nights!

In the middle of having our ensuite replaced.

We were going to do it ourselves, rip out the old sink/toilet/shower take off the tiles etc.

Our intention was to reboard with a cement backer board (the new tiles we brought seem to be just over the recommended weight for plasterboard).

Anyway we decided we didn't want to miss something or do it wrong and end up with issues down the line.

So we found a number of people with good reviews, got some quotes and went with what ended up being the 3rd cheapest (all but one in a fairly similar price range).

Anyway, progress has been slow (not a major issue for us, as long as everything is spot on when complete).

After he ripped the old stuff out he said how the plasterboard was in good condition except for one section which would replace.

We explained we wanted the backer board due to it being 1. Water resistant and 2. Takes a heavier weight load.

Turns out there's an industry shortage of tile backer board (something the Travis perkins site backs up).
He then spoke to his plasterer mate (first alarm bell) who said that the walls where the shower will go will be fine in water resistant plasterboard, and he could use special fixings to take more weight (as I understood, it wasn't the fixing that was the issue with the weight, its the plasterboard itself).

We reluctantly agreed, as long as he guaranteed to resolve any problems in the future.

Anyway, as it stands.
He's replaced some flooring, with normal chipboard. He's reboarded 3 walls, 2 with water resistant plasterboard (with normal plasterboard screws). And put on 3 rows of tiles, on one small section of wall.

Where the two corners of plasterboard meet, there is a half inch gap, unsealed. The horizontal joins are tight but unsealed.
Where the floor should meet the wall, there's a inch gap.

I believed (and how I intended to do it) was all joints should be tight and sealed (and researching this weekend that the shower area should be "tanked" ideally.

I was also have thought he should have used water resistant chipboard. Lined over with ply, fitted the shower tray and then tiled, as it stands the shower tray will be just pushed up to the tiles and sealed after.

My concerns are that - tiles and grout are not truly water proof, so any water ingress will meet this water resistant plasterboard and inventually seep to an unsealed joint, or wall the way down to the inch gap and soak into the chipboard or make its way to the joists / ceiling.

Any failure of grout or the shower tray sealant will have it run down the tiles to the same area.

Am I being over the top and reading to many horror story's?

Issue is, if these are issues, even if I mention them and he sorts them, what other issues going forward will we hit...

I know you should address them direct with any concerns, and give them chance to put things right, but at the moment we feel like saying we don't feel confident continuing, paying him for the little he's done and finding someone else to complete the job... sigh

I'm no expert, but I refitted a bathroom myself and picked up the following nuggets of info:

If your fitter is using moisture board (green plaster board) and is planning to tile over it, I would definitely want it to be tanked. Tiles and grout aren't particularly waterproof, and I wouldn't want problems down the line.

For my shower over bath I used the moisture boards dot and dabbed onto the brick (which I found out 6 months later isn't recommended, d'oh) and then used waterproof shower panels on top. I didn't tank it, but things have been fine. My logic was that the panels would be far more waterproof than tiles so any water ingress would be minimal. 5 years of use and it's been alright!

As for the chipboard on the floor - I'd be very concerned about that. I put 12mm waterproof ply on top of my 19mm floorboards and tiled on top. My neighbour took up the boards and put down brand new chipboard. His tiles are all cracked, mine are fine. There's a few hairline cracks in the grout, but I think some movement is kinda inevitable so I'm ok with that.

Thanks for the reply, you seem to be along the same lines as my none expert, but researched opinion.
For the floor, it'll be a thick vinyl, so shouldn't have any issues if there's slight movement, it's the concern if water makes it's way through the tiles/groute/through shower sealant it'll act like a sponge and suck it all and distort.

Also not sure how he's intending to fix the shower tray. It doesn't have a riser kit, so as I understand the usual practise would be to put it on a bed of cement, but this isn't recommended on chipboard, especially if it's not even sealed to the wall and under the tiles etc, but merely sealed to the side of the tiles where there's n increased chance of movement which would then cause the motor to crack.

I just feel I could have taken my time, and researched and done a better job so far, but still be concerned I hadn't thought of everything.

BUT, I know in my line of work, a lot of things don't need to look pretty, just meet a requirement to be functional and then everything else just sort of comes together.

Maybe in this line of work these aspects don't matter, as long as they are secure, and the following steps bring everything together... -... Or mask all the problems.

Lots of pondering tonight, problem is he's a lovely guy, but I don't want to be ripping it all out in 5 years time again because I kept with him through some level of pity.
Awkward.