I have bought an acrylic shower tray from B&Q but the instructions are
missing! I've read a few threads about installation, but still have a
few of questions to ask:

1. Once I have sorted out the waste pipe and levelled the tray using
the adjustable legs, do I stick the sides of the tray to the wall with
adhesive?

2. The tray does not have upstands. Can you buy something similar to
go up the wall behind the tiles (not yet fitted) to help seal it?

3. Does a tray like this require support underneath other than the
legs themselves? If so, quite a lot (of mortar?) would be required.
Would expanding foam do the trick?

Many thanks to anyone who takes the trouble to offer answers.

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember saying
something like:

1. Once I have sorted out the waste pipe and levelled the tray using
the adjustable legs, do I stick the sides of the tray to the wall with
adhesive?

No need for adhesive. The tray just sits there on top of its seating
mortar or foam, whatever you use.

2. The tray does not have upstands. Can you buy something similar to
go up the wall behind the tiles (not yet fitted) to help seal it?

Upstands, while nice to have, aren't always necessary if you tile down
properly. To be on the safe side you can get a seal that does just as
you say.

3. Does a tray like this require support underneath other than the
legs themselves? If so, quite a lot (of mortar?) would be required.
Would expanding foam do the trick?

I've come across ones that only had the legs in use - they were cracked,
so I wouldn't trust the legs alone. Mortar would be great, but what's
'quite a lot' in your case? A couple of spadefuls would be all it would
need and once done, no further worries. Expanding foam can be used, but
not so much as load bearing, more to stick the tray to the floor.
I've used EF successfully under cast resin trays, but I avoid the
plastic trays like the plague, because they're crap.
--

Dave

Thanks for the useful advice, Dave. Mortar it is.