Unless the user is very careful indeed, water is dripping
through the bathroom floor/kitchen ceiling.
The bottom partial tiles were lose, being held only
by the bead of silicone sealant.
little plaster was left intact I have chipped
away leaving this gap. What is the best way to
proceed? Is there something waterproof I should
be using to fill the void, and will this be the same
product that fixes the tiles back?
Difficult one. You probably know that ideally you should pull off more
or all the tiles and replace the backing board (this scenario is exactly
why I favour using more expensive waterproof board like Aquapanel,
rather than plasterboard as has been used here by the looks of things.
How secure are the tiles above the gap? Isn't the board mushed there too?
I think it will be very hard to effect a decent bodge-type repair here
which doesn't leak - you need to create a really rigid surface in that
tiny gap which you can fix tiles to.
I wonder whether the best solution would be to fix a single row of new
tiles (white, to blend with the tray) around the whole perimeter of the
tray and covering the gap, a bit like a skirting board?
(this scenario is exactly
Disagree. As long as the board is firmly fixed, and properly sealed it
never gets wet anyway.
Actually this is a case where expanding foam would work. It will seal
the gap and it is rigid enough t tile over.
But I a with you on removing all the tiles, making good the board,
using silicone to seal the board to the tray and retiling. Starting from
the base. A sliver of tile at the worst possible point is terribly bad
If you are gong to bodge use foam. That will render the thing watertight
until the job can be done properly.
"when in doubt, rip it out"
After a lifetime of DIY on cars and houses I have come to the conclusion
there are only three sorts of repair that are worth doing. Car examples
1/. Cosmetic. Stuff the rotten sills with newspaper, slap on filler
touch up and sell.
2/. Cheap & ugly but functional. Weld a piece of angle iron under the
sill. Will get you trough the MOT.
3/. Pukka. Take the old sill right off and fit a new one.
Farting around welding bits of plate and filling is a complete waste of
time: its never as good as new sill, it takes 5 times longer to fit,
and chances are it will rust through in short order.
After many instances of attempting that class of repair, age and
experience sets in,and you simply don't even start that way. Quick
functional bodge, or pukka job.
I this case either welly in foam or strip the tiles, make good behind,
Or stuff with newspaper and filler, stick the tiles back on and sell the
I agree with your disagreement(!) but have seen enough leaking showers
in my time to know that leaks are likely to happen, and if they do, then
the extra initial cost of providing a decent substrate is piffling in
comparison to the extra work which the OP's now faced with.
Hmm, possibly but not convinced. Even if if the foam's rigid enough, I
don't fancy the OP's chances of achieving a surface which is flat and
firm enough to tile over. Could he fill the deep gap with foam and then
bring it up to the right level with something else non expanding, maybe?
All very awkward to do with the height of the gap being so small.
Maybe worth a go though, and use my over-tiling suggestion afterwards if
it still leaks?!
Easy. Just slice it with a carving knife. Done it several times. If
really botered plaster over.
Could he fill the deep gap with foam and then
Sure. fill with foam an wedge a bit of batten in the gap.
Not much gets past foam ;)
Unless you wish to spend megabucks on dry rot (or other rots) later I
suggest you forget a botch up and either do a proper rebuild of the
lot or a decent partial repair
1) take off at least the first set of complete tiles all round - use a
Fein multimaster or pay for new ones. If you can take of more so much
2) render the back brickwork with a strong water proof render eg 1:1
splatter coat 6 mm thick with Sika No 1 AND SBR both applied as
3) if at all possible move shower tray so it is UNDER the new render
on all three sides (or bring out the render so its default postion is
inside the shower tray
Fill the void between edge of the shower tray and brick wall with
Polysuphide mastic (its expensive) so that it comes up to and level
with the top of the shower tray
4) use Wedi board to line up with your plaster board once you have
found sound plaster (by the way I endorse all oponents of plasterboard
for showers - it is not sensible to rely on one piece of trouser
elastic - better to get a belt braces and piece of string and spare
trousers underneath - when it comes to showers.
5) but the Wedi up with a good silicone sealant on the joint
6) use a suitable glue for the Wedi to render
7) avoid ferrous fixings
8) bring the Wedi down to about 10mm or so short of the shower base
and fill the resultant void with psulphide mastic
9) put in an extrusion tile / tray interface of plastic with rubber
seal bedding the whole lot in polysulphide mastic such that it forms a
complete perimeter barrier to falling water
10) retile using epoxy grout
Next time you make a new shower recess the edge of the tray into the
wall 5 mm and have the plaster or plywood / Wedi run inside the shower
tray before you tile