On 15/02/2018 11:24, Roger Hayter wrote:
GB wrote:

Installing shower tray with upstands - this seems to be a right *******
of a job. According to the destructions, you are supposed to install
cement board down to the floor, then chip away 5mm from the face of the
board to a height of 115mm, so as to inset the shower tray and upstand.
I spoke to Mira's technical helpline, who said: "ask your builder, as
he'll have the right tools for the job".

The destructions show this being done with a hammer and bolster. Well, I
have those, and it's not going to work, is it?

I'm using 12mm Aquapanel cement board, btw. The only way I can see to do
this is to add a second 5 or 6mm layer of cement board on top of the
Aquapanel, stopping 115mm short of the floor. Thus neatly doubling the
cost and the work of preparing the room.


http://resources.kohler.com/plumbing...ira-flight-low
-shower-trays-range-installation-and-user-guide.pdf


My impression is that most shower trays don't have upstands. Is this why?

A very recent thread in this group about this problem suggested simply
removing the bottom 115mm of the board (PB in that thread) and leaving
a moderately deep gap in front of the basic wall structure. I can't
see any great problem with this approach, especially if the underlying
wall is not too vulnerable to water damage. But i've never tried it.

There's a 1.5" gap behind the cement board, apart from where the battens
are. So, that's an issue.

The correct way to do this, apparently, is to remove the 5mm, then flood
the gap between the shower tray and the remaining bit of the cement
board with silicone. That sticks it all together and makes it rigid, as
well as water-tight.