Dave wrote:
jacob wrote:

Have finally got hold of a shower tray (1200x800 cast resin/stone ).
It says that it absolutely must be laid on thin dry mortar bed 5mm min
supporting the whole thing and the edge.
Sounds reasonable but in fact this is virtually impossible to achieve.
It's very heavy and impossible to manouevre to sit close between three
walls and to fiddle about with mortar etc to get it perfectly level.

Having noticed in your earlier posts that you were dealing with an
alcove installation, I wondered if you'd come back with that problem,
but I thought you were using one with adjustable feet in the corner?!

I'm beginning to think I should have bought one of those expensive
ceramic ones with an adjustable foot at each corner.

Well...

A while ago someone suggested putting a couple of wooden strips down,
then mortaring between them, resting the tray on the strips then sliding
the strips out - it worked well for me on a 900x900. Obviously there's
no mortar where the strips were but if this is against the side walls
it's probably reasonable to assume that this bit won't get jumped on.

Yes I asked the same question as Jacob here a few months ago, and this
was the answer I got. Have a google for more details on the technique.

It certainly worked like a dream, with a perfect installation and no
spinal damage! I used three wooden slats IIRC, but instead of placing
the outer ones flush with the wall, I positioned them about 3-4 inches
in, as I felt it was important that mortar went right up to the edges to
support the rim, as that's where any leaks will occurr and you really
don't want any sagging. Also, these trays have a hollow, unsupported
area all the way round near the sides, which IMHO makes it all the more
important to ensure the actual edges are fully supported.

David