shower tray
 

i am starting with a bathroom refurb and have bought an aqualux walk
in shower enclosure, the enclosure came with a polystyrene base, in
the past ive fitted a stone resin tray which seems to rely on weight
to remain stable. The Aqualux instructions are based around setting it
into the wall and bedding it into mortar. Does anyone have any tips /
experience of fitting polystrene shower trays that they could pass on

ive also got a bar type mixer shower, i intend fixing it to a stud
wall, any ideas/tips for fitting? ive seen a fixing kit on screwfix pg
285, item 56419-75 has anyone used these?

thanks in advance

andy