I'm nearing the end of my full bathroom refit and the MI for the Mira shower tray say it can be installed on either a bed of sand & cement, or silicone sealant. So if your MIs only say sand & cement then I'd either insist it's installed as per those MIs, or the fitter takes all responsibility for any future issues.
Fitting stone shower tray on floor (plumber says no cement required?)
- Thread starter glenimp617
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- 30 Sep 2005
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- 16,553
Well I've had another plumber round and he's said the same thing. Not to bother with cement 
I'll get a third opinion
I'll get a third opinion
Well I've had another plumber round and he's said the same thing. Not to bother with cement
I'll get a third opinion
These tradesmen can recommend that you don't need to, but you can insist that they do.
Associate
Had a new bathroom and shower fitted by a company a few years ago. After a few months noticed hairline cracks around the outer edge of the shower tray. Got the company back out and yep, you guessed it their fitters didn't install the tray on a bed of mortar. Cue the company was liable and had to uninstall pretty much everything and most of the tiling and do it all again. Very expensive mistake, for them..
Soldato
I have an expensive Italian stone resin tray with underfloor heating. Instructions say silicone only. I was shocked and wanted to use cement - I even telephoned their support and was told to use a really thin even bed of silicone. I did, that was 12 months ago and it’s still sweet.
My advice, read instructions.
My advice, read instructions.
Soldato
- Joined
- 4 Apr 2003
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- 7,981
Depends if flush fit to floor or if they are on riser feet too. Also depends on the tray. High quality cast/stone trays can be self supporting so don't rely on a bedded base. Cheaper ones often do, equally some cast/stone ones do due to the formed shape.
On a flush fit then in my experience as a minimum a very dry mix mortar in an ideal world. You can just use a high quality silicon sealant on the base if it's flush to wood, tiles or concrete as it will stick very well and if the tray is suitable. However if laying onto a thin screed or uneven / broken floor then mortar is the way to go.
If it's on risers then no mortar but silicon under the feet to stop it sliding/moving.
If they just want to lay the tray and put some sealant round the back and front then pick another fitter.
On a flush fit then in my experience as a minimum a very dry mix mortar in an ideal world. You can just use a high quality silicon sealant on the base if it's flush to wood, tiles or concrete as it will stick very well and if the tray is suitable. However if laying onto a thin screed or uneven / broken floor then mortar is the way to go.
If it's on risers then no mortar but silicon under the feet to stop it sliding/moving.
If they just want to lay the tray and put some sealant round the back and front then pick another fitter.