Installing a shower tray - directed to bathroom installers

[Ookysoft]

Hey Kids!

I'm about to rennovate a bathroom.

The floor is chipboard, from memory approx 15mm thick.
The previous shower has leaked and dripped all over the place. The floor was carpeted and is black and blown with mildew and water damage.

It's still undecided whether to install vinyl, laminate or tiled flooring.

There's a stone-resin tray without legs, to install.

So....

Do I replace the whole floor with, say, 1" plywood to ensure a stable base for both the tray and to flooring? If so, I assume I cut right to the edge across the joists but down the length of the joists nearest 2 walls to keep the ply fully supported. Then do what with the nubby bite to the 2 wall edges [ assumes the walls are studs and maybe between joists???] to give a stable tiling surface right to the edge..... Maybe I'll be lucky and the walls will be on joists so I could piggy-back a floor support to the joist. Or should I 'somehow' install nogging in the floor running under the walls between joists...... somehow.......!

Regards the tray, the last one I installed I used a 5:1 mortar mix to bed it on. Is it possible to use a quick-set for this - maybe use a pre-mix pack and adjust the assumed 3:1 to 5:1 with extra soft sand - this bathroom needs to be back in use as quickly as I can so waiting for the mortar to set before treading on the tray for re-tiling is going to be a pain. Also, how thick should the bed be? Enough to take up the discrepances in the tray plus a few mm??

*wonders if there's anything else I need to ask* I can plumb, kinda tile, construct the enclosure [ trick here seems to be make sure the tray is dead level ].......

Really it's just the floor.

To complicat matters I am to keep the bath/loo & sink usable while the shower goes in so if I am to replace the floor I'm to do it in sections.

 

[JohnD]

Most likely the floor was built wuth 18mm T&G Chipboard. It might or might not have been a water resistant grade. Your problems sound very familar.

I was pleased with mine which I did in 18mm WBP ply (if I was rich enough I might have used Marine ply) I used a breathing stain (like i use on my hardwood front door) to give a more attractive and water resistant finish (I use washable mats). My joists ran to within a couple of inches of the wall, so i let the edge of the ply overlap them and fitted skirting above. It's much more rigid and quiet than the old chip rubbish.

i used square edge boards deliberately, in sections so I can get at pipes and cables under, and Stainless countersunk screws. The joints are very straight and tight. You may also like to brush out all the old garbage, insulate pipes and treat joists to some cuprinol green while you're doing the job.

No strong opinions on covering. Some folk say you shouldn't use impervious sheet coverings like vinyl so you can take them up to dry the floor when you get a flooded bathroom. i wouldn't have tiles because it then becomes a very unwelcome task to get at any pipes and stuff under the floor (I have a tiled disabled bathroom conversion in a relation's house that I'm not looking forward to taking up to investigate a possible leak)

 

[Ookysoft]

Thanks for that!

Any thoughts anyone ref ther bedding mortar?