Low profile shower tray fitting, advice please

[conflax]

Hi - need some sensible advice please

I am fitting a new shower in the corner of my bathroom. I've got 18mm chipboard on the floor topped with 9mm plywood with a hole for the waste, a plumber has fitted the waste in place, flexible to marry up to the tray. On the walls I've taken down the plasterboard and replaced with Hardibacker all round the shower area, so at the moment it's a bare shell of board/ply.

The tray is a low profile 25mm one with no lip etc, 900mm curved quadrant with a flat base for cementing. I'm worried about 2 things mainly, around tiling :-

1) I am keen to tile the floor first then seat the tray on top of this, as it's low profile and would give a good seal round the bottom of the tray. Is this sensible specifically with a low profile flat bottom tray? I'm also worried if I tile first the waste won't sit flush with the depth of 18mm chip Plus 9mm ply plus 25mm tray - but if I tile up to it, it will be VERY low, and there's a risk of leaking or needing loads of silicon.

2) Should I fit the quadrant flush with the Hardibacker then tile down onto it? This seems like the most popular approach but i'm concerned that i'll lose radius from the curved tray and the enclosure won't fit. What's the best way of doing this?

Thanks!​

 

[SimonG]

1 yes
2 no.

And sort that floor out properly before you tile or lay the tray.

 

[conflax]

1 yes
2 no.

And sort that floor out properly before you tile or lay the tray.

Thanks - what's wrong with the floor? Ply too thin?

 

[Harvest Fields]

Thanks - what's wrong with the floor? Ply too thin?

No. The fact it is ply.

 

[conflax]

No. The fact it is ply.

OK - Sorry i'm being a novice here, what should I have then?

 

[Harvest Fields]

OK - Sorry i'm being a novice here, what should I have then?

Needs to be a waterproof board.

 

[conflax]

Needs to be a waterproof board.

right - cheers

 

[king of pipes]

I would fit hardi backer on top of the floor especially on chipboard work out your tiling and fit a baten low down allowing you to do all the tiling and grouting up even fit the shower mixer and shower head fittings before fitting the tray it can then be siliconed against the hardibacker and laid on quick set tile adhesive ,the waste connected and tested before compleating the tiling which will only be say half height tile down onto the tray doing it this way you minimise the risk of damaging the tray and can be rest assured there will be no leaks . cheers kop

 

[S.P.S.]

Stick tray down first, silicone it to the walls, then tile.

This is how the shower enclosure is designed to be fitted, so they account for the “loss in radius” they have adjustment in the wall channels anyways.

Hardi backer the floor, make sure it’s glued and screwed to the floor, and prime it. not ply. Make a cardboard template of the shower tray for cutting the tiles. Don’t tile the floor before fitting the tray.

IF your shower enclosure is installed correctly and sealed correctly, as per the instructions. IE, seal the tiles to the tray before fitting the enclosure, then only seal on the outside of the enclosure, ensuring all joints are sealed up 150mm high. Don’t seal anything inside, unless explicitly told to do so in the instructions.
Then there should be no leaks out of the shower tray/enclosure. Unless you’ve bought one of those aweful frameless things...

Stu.