Shower alcove update

[diferentshades]

Reposted this, as i think i put it in the wrong forum:
Hi guys,


finally finished the shower alcove prep. I have silicones around the raised plywood frame as a precaution. The plasterboard s go down almost to the floor, shy by about 2 inches.
Decided to go for homelux matting, will be wrapping it around the walls horizontally rather than top to bottom. Two reasons for this I can wrap round in 2 pieces, one above the other, and secondly, I won't have to worry about tapping up the corners.
I have a question though,


The tray when tested, was quite snug with the plastic still on. It's one of thos low profile ones without upstand. The tray is slightly wider at the base than the top, it sort of flares out to the base, because of this, there is a gap of about 4 mm or so around the top face of the tray.


Do I fill the gap with tile adhesive till its flush with top of the tray and then over lap with the membrane? Or just fill with silicon?
do I need to over lap with the tray. I was going to go down to the ply base, but by the time I apply the adhesive and matting, I don't think the tray will slide in!


also I was going to bal sbr the ply base and fix tray with tile adhesive, is this ok?
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[diferentshades]

Bought some homelux matting, topps had it for £50, but builderdepot had it for £41.72, so topps matched it. In case any of you guys are interested.

by the way, is topps rapid set ok to use to bed the matting in with, reason I bought it was that it was £10 for a 20kg bag, as opposed to the bal one which £30 odd quid.

bal also do a version for large tiles that's on offer for £15 quid, will this be ok?