Fixing down a low profile shower tray

[Besidethewye]

Apologies if this is a repeat - couldn't find anything with a search.

 

We have three shower trays to fit to a caber deck wooden floor.  

 

Two are 40mm deep and I see no great problem in fixing down.  The other is only 25mm deep and large (1700 by 900) all stone resin.  The instructions for the big tray say a bed of 15mm deep sand and cement.  Not all that convinced by sand and cement on a timber floor.  Wondering whether a flexible tile adhesive or even the spare sika floor adhesive we have might work better - staying flexible, filling the gaps and not so much at risk crumbling over time.

 

Any advice?

[Nickfromwales]

Forget sand and cement, its the worst advice given by far  

Ideally you should be gluing and screwing at least a 6mm layer of plywood down and then sticking the trays down into a bed of flexible tile adhesive.

Wet / prime the ply first and then it'll stick like shit to a blanket.  

[Miller3857]

Looking for similar advice but onto a screeded floor.

[nod]

I’ve fixed mine down with flexible tile adhesive 

I used two bags to fix Three 1200 trays down directly to the cabadeck 

It’s only to level them out 

once the tiles are on There never going to go anywhere 

[Nickfromwales]

4 minutes ago, Miller3857 said:

Looking for similar advice but onto a screeded floor.

Same applies, re the prime and flexible tile adhesive. 

 

[Miller3857]

Thank you!

[Nickfromwales]

22 hours ago, Miller3857 said:

Thank you!

Beware mould release agent on the underside of the tray ( from the manufacture process ). 

I use the tile adhesive like Ajax and scrub the bottom of the tray until I can see the adhesive wanting to stick to it, and then sponge it off. Apply a bit more as a bed for the tray to set into the adhesive you've applied to the floor.

[Besidethewye]

Thanks for that - quick and on point as ever!

 

Nick - why the additional layer of plywood over the caber deck?  Is that just to get an even surface and better adhesion?

 

I'll get in and scrub the undersides.....

 

Thanks

[Nickfromwales]

9 hours ago, Besidethewye said:

Thanks for that - quick and on point as ever!

 

Nick - why the additional layer of plywood over the caber deck?  Is that just to get an even surface and better adhesion?

 

I'll get in and scrub the undersides.....

 

Thanks

I'm not a fan of bonding directly to the 'laminate' top layer of Caber so that's just me. Seen enough decoupled to put me off.

2-part aka fastflex / ultraflex is an option in extreme situations ( more expensive than unicorn piss ) but a good exchange HERE for your perusal.

[Miller3857]

Thanks Nick for the advice so far, am I right in assuming then that the whole of the underneath of the shower tray is bedded in adhesive not just the bits that have been machined flat.

[CC45]

I did the flat machined bits - scrub them well first.  Flexi tile adhesive to stick it down - feels totally solid.

[Nickfromwales]

7 hours ago, Miller3857 said:

Thanks Nick for the advice so far, am I right in assuming then that the whole of the underneath of the shower tray is bedded in adhesive not just the bits that have been machined flat.

 

Just the machined sections