We have a shower cubicle of a non-standard size, with
block walls on three sides. I got a custom shower tray made from stainless
for the base of this shower, with a lip on it of about one inch. I tiled the
of the shower and rested the bottom row of tiles on to the stainless steel
so that shower water would fall into the base and drain away nicely: no
worries about the integrity of the join twixt tiles and base here.
I then bought the good silicone stuff (can't remember the brand name, but
cartridge was £7.50 a time all those years ago) and the shower has done well
a few years.
The problem started about a year ago: the other side of one of the shower
walls is wallpapered, and the black bacterium started to flare in spots from
base up to about eighteen inches off the floor. The other wall is in an
adjoining room, and it too showed the same symptoms.
The tiles used are those flaming difficult ones to drill, and are about
inches tall by about ten wide.
I cursed my luck and decided to remove the bottom row of tiles, and the
work behind them was damp. The plaster at the very foot of the tiles for up
about a half inch was sufficiently wet that you could "rub" it through your
Its dried out for about three weeks now, hence I'm getting pestered to get
shower fixed (we have two other showers in the house, so no catty comments
personal stench please :-) .
But how to fix this: if I do what I did last time, the problem could come
My guess is that the water was somehow "wick"ing up the back of the tile and
up into the wall.
Current thoughts are to buy some of that plastic "quadrant" tile edging
the kind that is used to tile down to the top lip of a bath), and use this
keep the bottom edge of the tile off the stainless steel.
I'd also make sure that the bottom two inches of the wall are painted with
paint so that any water on its surface wouldn't seep in and work its way
I'm using one of those two-pronged damp meter things; it's not exact science
but its quite useful. The numbers have dropped since the shower was
decommissioned, but I guess that's to be expected.
Grateful if anyone has views on this; many thanks in advance.
I have just been dealing with a related problem with one of my
It's a Matki tray with a built-in "tiling upstand" round the back edge. It's
been in for about 10 years without any trouble except hairline cracks have
appeared across all of the bottom row of tiles.
When I installed it I followed the instructions to the letter. The built-in
"tiling upstand" is recessed into the wall, i.e. tucked in under the bottom
edge of the Aquapanel walls. All tiles except the bottom row are fixed using
tile adhesive in the normal way.
For the bottom row I followed the instructions carefully. The tray itself
has a load of silicone sealant behind the edge, between the tray and the
wall. This oozes over the top of the tiling upstand all round. So far, so
good. For the bottom row of tiles, I put a big bead of ilicone over the
front edge of the tiling upstand, and tile adhesive down to nearly the
bottom of the aquapanel. The tiles were then squidged into this so they are
mostly adhesive fixed, but their bottom inch or so is stuck (and sealed)
with silicone. Then in one swift action I finished them off with a bead of
silicone between the tiles and shower tray and neatly finished this. When
all dry they were grouted in the normal way.
This was fine for about 8 years but then horizontal cracks appeared across
all the bottom row of tiles. I assumed (correctly as it turned out) that
with all the silicone behind, there was no real chance of water creeping
through and soaking everything behind, but last weekend I finally plucked up
courage to find my old stock of spare tiles and have a go at replacing the
Getting them off was a right old faff. I used the angle grinder to cut a few
slots so that I could break out sections without damaging the next row up.
It turned out that the horizontal cracks were all in the area between the
silicone and tiling adhesive - I guess the two materials move slightly
differently so the tiles are stressed just there.
So now I need to work out the best way of re-sticking and re-sealing the new
bottom row of tiles. Maybe there is a better (less flexible?) type of
silicone for sticking and sealing the tiles to the tray?
For your stainless steel tray this method (bottom inch or so stuck using
silicone) should give a good seal but it does seem to require some special
trick (or extra strong tiles) to avoid cracking later.