Fitting a shower tray

[Craigybaby69]

Morning
Is it neccessary to bed a shower tray on a mortar base if the floor is completely level in the first place?
Cheers Craig

[Little Lofty]

Yes it pays to bed it onto something, I usually use floor tile adhesive. I'm sure Mira recommend a bed of silicone, so that could be an alternative.

[B17NNS]

I'd still be tempted to lay a thin notched bed of floor tile adhesive. Eliminate the possibility of all rocking/movement.

[Craigybaby69]

Cheers, but what about a sand and cement mortar mix? Plumber says not neccessary when floor level and tray won't move and mortar can cause problems if it shrinks anyway. Sound plausible but wonder if I'm being fobbed off.

[Rickyy]

The floor being level usually makes zero difference to the level of the tray. The moulds are usually out slightly, so the tray will usually need levelling up to an extent.

It's a pig doing it with a mortar mix though, so I'll second the tile adhesive route!

[Busterbulldog]

It depends on the type of tray and the type of floor. For instance a sand cement mix under a plastic tray can fail and make crunching noises after a while. More info needed.

[Craigybaby69]

Tray is heavy, 2 man lift. Floor is 19mm chip wood. Tray fitted this morning.

[Craigybaby69]

Just noticed on the instructions it says the part of the floor where the tray sits should be cut out and replaced with plywood 18mm or similar. Is 19mm chipboard similar?

[robwilk]

just fitting one my self today and was going to put the tray on filler foam but for some strange reason \i desided to read the installation instructions and it says must be bedded on sand and cement so job stopped until tomorrow. Ive used ply under mine but onlt due to me having to raise it up as the trap hits the joist.
Im going straight on chipboard in the other bathroom.

[Craigybaby69]

Cool, think my plumbers been lazy, thankfully he's got it perfectly level on all sides but I shall be taking it up with the builder tomorrow.

[soi6]

Use hardibacker floor sections .Or tile backer boards screwed and glued onto ply .Bed down with flexi adhesive

[eps]

Craigybaby69 said:

Just noticed on the instructions it says the part of the floor where the tray sits should be cut out and replaced with plywood 18mm or similar. Is 19mm chipboard similar?

No.

Does it mention WPB Ply? Use ply as it will be more structurally sound than chipboard.

[Craigybaby69]

Too late, it's in

[Little Lofty]

I wouldn't worry about it not sitting on ply, chipboard isn't as strong but it should be strong enough.

[loughran]

Chip board is fine as long as it stays bone dry.

[eps]

loughran said:

Chip board is fine as long as it stays bone dry.

This...

[Spudler]

As mentioned chipboard is perfectly acceptable, 22 would have been better.
Another option is to use window packers to take up any discrepancies between floor and tray then use adhesive rather than sand & cement. Foam can also be used with the packers ONLY if you're handy with a foam gun.

[Rollin]

You're not tiling on the chipboard are you?

[soi6]

some right FKKN cowboys here......

And did your builders put the floor down?

if they did, i hope you asked for a cheap nasty job that will not last long !

Edited by soi6 on Monday 24th November 19:01

[wolfracesonic]

eps said:

loughran said:

Chip board is fine as long as it stays bone dry.

This...

Can't see any danger of water being about in a bathroom

If you do use sand and cement it needs to be a lean mix, 7 or 8 to 1, no stronger than the shower tray itself in other words