Shower tray mortar bedding - how much to mix up ?

[mh007e1233]

Hope this is the correct forum to post this in!...fitting a stone resin 900x1200 shower tray & can find lots of info about mortar mix etc, but can anyone advise roughly how much mortar I should mix up to fit a 900x1200 tray @15/20mm bed???,,,,sorry if this is mega elemetary but I don't want to get all the way to this stage and have not mixed enough

 

[swbjackson]

A bit of basic maths is required.

Volume of mortar needed at 20mm thick = 1.2 x 1.9 x 0.02 = 0.0216 cu m

A tonne bag of sand holds about 0.6 cu m of sand therefore 1 cu m sand weighs about 1700 kg.

0.216 cu m of sand therefore weighs around 37kg.

As bags of sand weigh in at 25 Kg ( I think) you'll need 2 bags of sand and need to knock up about 1.5 bags for a 20mm bed.

Mike

p.S. Check the maths as it's getting late.

 

[mater]

i would say dont make your bed any more than you have to, can you get away with 10mm?

 

[Softus]

I don't think you'll need more than a bag of sand - between one and two buckets of mortar is likely to be enough.

Try the tray dry first and check it for level. Unless you need the mortar to allow you to make the tray level, then you only need it to fill in the 'low' points in the underside of the tray.

 

[kevplumb]

i would say dont make your bed any more than you have to, can you get away with 10mm?

spot on

you bed the tray evenly across the full width

not boch it trying to get it level

 

[kevplumb]

I don't think you'll need more than a bag of sand - between one and two buckets of mortar is likely to be enough.

Try the tray dry first and check it for level. Unless you need the mortar to allow you to make the tray level, then you only need it to fill in the 'low' points in the underside of the tray.

SPHERES

 

[Richard C]

Stone resin trays are basically concrete with a thin resin gell coat over the top & so can be quiet brittle. The weak mix bed is to provide continuous & evenly distributed support over the entire base of the tray & a 10mm bed is quiet sufficient; on that size tray, 1 ½ - 2 buckets should do it.

 

[tryitandsee]

Just out of interest, I was told that you can bed the shower trays down on tile grout 10 to 20 mm thick. The grout sticks well to the base ie plywood pretty well. Seems plausible to me, has anyone done/tried it this way?

 

[mh007e1233]

Thanks guys - all really useful, the tray is perfectly level on my 18mm WBP base, so I'll go for ~10mm just to give it something to hold...

Is a plasticiser essential?, I need so little for this job its hardly worth buying 5L....or maybe you'll tell me differently?

 

[mater]

use a small drop of fairy liquid, but watch you dont mix it to wet