Sharp or soft sand for bedding shower tray on a weak mix

[Antony2008]

Good morning all - I'm about to fit a stone shower tray that advises bedding down on a weak mix. After reading previous threads on the subject I know I've to use a 5:1 mix but found conflicting advice on whether to use sharp or soft builders sand. I'd appreciate if someone could give a definitive answer (and perhaps the reason/s for (not) using one or the other) - I'd hate to be re-fitting/re-placing the shower tray at a future date .

Thanks in advance.

Antony

 

[kevplumb]

soft sand don't have lumps

 

[Richard C]

Use soft sand; stone resin trays are relatively brittle & the point of bedding them on a weak mix is to ensure they are fully & evenly supported so there are no stress points. The last thing you want is to create potential stress points on the underside of the tray & this is more of a risk if sharp sand is used.