How flat should shower trays be?

[smallsteve1]

I have received a stone resin shower tray and as best as I can measure, one corner is 3 mm lower than the other three (across the top of the tray edge) and I don’t know whether this is an issue or not? Are these things normally completely flat, or is it the norm that they are out of flatness by a few millimetres?
This is the second tray I have received from the manufacturer, as the first had the same problem but in a different corner. I’m not sure what to make of this, as I have paid a fair amount of money for a good quality tray i.e. it is not bargain basement stuff.
Are there any fitters out there and provide some insight as to what I should expect and whether I have a problem or not? TIA

 

[Hugh Jaleak]

Tray should be set dead level, fall is built into the tray base to allow the water to drain. 3mm isn't a massive amount, how are you measuring it?

 

[oldbutnotdead]

As above, as long as the fall in the tray is such that it drains properly it'll be acceptable. Not sure exactly how you've determined one corner being 3mm low but when you set it on its mortar base you should be able to split the difference ( so 1.5 runout from actual level). You can hide that in the tile grout

 

[smallsteve1]

Tray should be set dead level, fall is built into the tray base to allow the water to drain. 3mm isn't a massive amount, how are you measuring it?

I used a spirit level and packers (Broadfix from Screwfix), measuring each end of the tray and then across the diagonals. Not an exact science of course, but should be fairly close.

 

[Hugh Jaleak]

In the grand scheme of things, 3mm across that distance is negligible, as oldbutnotdead says, it should be pretty easy to 'lose' it in installation. If it is too much of an issue, ask for the tray to be replaced, but it's also entirely possible the Manufacturer will claim its within acceptable tolerances.

 

[oldbutnotdead]

How big is the tray? 3mm out on a 600 x 600 would be a bit poo, on a 1000 x 1600 not so much of an issue. To be honest, yes the top should be flat (+ or - 1mm), if you've paid top dollar then take it back and go through their stock til you find one that's in tolerance

 

[smallsteve1]

How big is the tray? 3mm out on a 600 x 600 would be a bit poo, on a 1000 x 1600 not so much of an issue. To be honest, yes the top should be flat (+ or - 1mm), if you've paid top dollar then take it back and go through their stock til you find one that's in tolerance

It’s 900 x 760 and I bought it online, so there’s a bit of an issue there! :-/

Really awkward with spirit levels as you can easily lose a millimetre here and there so my measurements are not exact. I also suppose that my spirit levels could be slightly out, but then again that should all be relative i.e. if you use the same spirit level for every measurement, then it should be fairly precise.

 

[Deleted member 292770]

if you use the same spirit level for every measurement, then it should be fairly precise.

No , it just means that every measurement will be out by the same amount.
you can test your level by setting it on a surface then turning it around to see if you get the same result.

 

[oldbutnotdead]

Or block the waste hole and fill it with water...

 

[smallsteve1]

No , it just means that every measurement will be out by the same amount.
you can test your level by setting it on a surface then turning it around to see if you get the same result.

Good point, had forgotten about that! Thanks