Fitting shower trays - sand& cement / tile backer / tile adhesive?

[Moonshine]

I am going round in circles about fitting these damn shower trays, basically i have 22mm caberdek and going to fit a shower tray on it (the instructions just say 8mm mortar above it to bed into, other people i have spoken to say i need 6mm of hardie backer above the chipboard first (screwed down)

 

Go on then do your worst to how does BH think a shower tray should go down? (not in this case the walls are fibre cement and i will be adding a tanking layer to it, and a seal tape at the joint to the tray)

Edited February 3, 2023 by Moonshine

[markc]

Last couple of trays I fitted were the cast ‘stone’ ones, very heavy and flat bottomed so I dot and dabbed heaps of cheap silicon all over the area and dropped them in place. 

[Bozza]

@Moonshinein two weeks I am refurbishing my parents bathroom to replace their bath with a (heavy) low profile shower tray.  Their floor is chipboard.

I’ve been researching this very question, as though I can do plumbing etc I’m not a trained plumber or anything.

 

The instructions I’m reading and what I’ve learned, are for a timber floor the mortar bed needs to do onto min of 18mm ply.  As I’m going to have to hack up their floor anyway I’ll be using caberboard  or similar apart from the footprint of the tray.  Though not needed I think I’ll seal the ply with PVA before putting the mortar bed down.

 

my understanding in your situation is that you should put the tray on the chipboard, template around it, then replace that section with min 18mm ply.  

 

 

 

 

[Bonner]

Spoke to my plumber (who is very thorough in everything he does). Never used sand and cement. It used to be tile adhesive but now it’s the cheapest mastic on the shelf (No nails, silicone or even caulk). It’s just a bed to prevent concentrated loading

[SoldierDog]

Be aware that if the manufacturer says sand & cement base and the tray cracks when its down, they usually ask for photo before sending a replacement for just this reason.

[Conor]

I used an entire tube of silicone, along all parts of the supporting web / edges, as per my plumbers reccomendation. Big fat bead. That was on top of a ply deck. Instructions said something rediculous about a sand and cement base.

[Marvin]

5 hours ago, Bonner said:

Spoke to my plumber (who is very thorough in everything he does). Never used sand and cement. It used to be tile adhesive but now it’s the cheapest mastic on the shelf (No nails, silicone or even caulk). It’s just a bed to prevent concentrated loading

I use tile adhesive if levels need to be made up on the resin stone shower trays. If on wood I always seal the wood first.

[Moonshine]

Decided to go 6mm tile backer screwed down, then sand and cement as per the instructions. Surprisingly it went o.k (glass lifters were a saviour!!!) though need to test water through it

 

[Conor]

So basically you ignored a load of random amature's opinions and instead went with the manufacturer's instructions? For shame.