By Chris Williams,
WetWorks Bathrooms. November 2013
must be the most common problem associated
with the housing industry. I have been renovating and repairing
13 years and have come across literally hundreds of people who have had
showers. Some of the renovations I have done have shown that the shower
leaking unbeknown to the home owner. In fact, I can't remember very
demolitions I have done and not found the shower to be leaking in some
leaking shower is generally the catalyst for a renovation but I have
also come across
homes that are only a year or two old that have leaking showers and
need to be repaired. Some
people just can't afford a renovation on a bathroom that really does
and just want to stop the leak before it causes even more damage to
It isn't cheap to
repair a leaking shower properly, so one needs to ensure that whatever
method of repair you choose is the correct one for your type of leak.
sounds simple but a shower can leak from several different sources and
sometimes even a phantom leak can put you off the scent. I once fixed a
leak for a lady
who had the whole shower ripped out and replaced by others and it still
leak. The leak was actually a very simple fix that was overlooked. I
that shortly. Also, a teacher I had years ago at the MBA told of a
story and it was later found that the water was coming from a leaking
A leaking refrigerators ice maker caused me some worry once. The water
behind the fridge under the wall into the hall, under the floating
the hall and came to the surface just outside the bathroom a few months
the renovation. It is very important to know where the water is
coming from before you rip into it.
going to pay is the question I hear a lot. It’s a common
misconception that a leaking shower will be covered by insurance. Not
but some leaks are covered. I am certainly not any kind of insurance
most of the policies I have discussed with clients all seem to
much the same thing. Usually they say, if a pipe leaks, it is covered
the water leaves the shower rose it is your responsibility until it
floor waste. I have personally only ever encountered 3 instance of
from leaking pipes behind the wall sheets in the shower. All the others
have been leaks from screens, hobs and membranes. One of the exception
of leaking pipes was the shower I mentioned in the previous
paragraph about the lady who replaced the entire shower and it was
found to be
a leaking pipe. She had a handyman replace the shower head some months
and he had not used enough sealing tape on the threaded connection at
and a fine water jet was leaking back into the wall and took some
build up and start soaking into the carpet in the adjacent room. I have
of how she got on financially with that one. The other two were never
detected as leaks but found after demolition during full bathroom
renovations. More details of these below.
Shower screens can
leak. Water can run down the glass into the
aluminium frame, travel a bit and then come out usually at the corner
tiles. To check for this kind of leak make sure it is very dry before
start. Have one person in the shower with a hand shower spraying the
another person outside looking for leaks. Use lots of tissues and keep
everywhere and looking at the tissues. You will see the tissue get wet
you will notice water building up in any one spot. A common mistake I
is someone seals up the inside of the screen to the hob or floor. The
should only have silicone on the outside allowing any water build up
frame to escape back into the shower. If you locate a leak clean the
it is spotless, let it dry out and use a Neutral cure, antibacterial
to seal it up.
Shower hobs are a major cause of
problems. Rarely have I seen one done correctly. This could be because
correctly they don’t leak so I never see them or it could be just that
never get built properly in the first place. Whatever the case, nearly
I see is the cause of a problem. Never have I built a hob for a shower
never will. They are trouble.
The main problem with them is that
people put the shower
screen on the wrong side of the hob. The screen should sit flush with
inside edge of the hob so water running down the glass continues down
hob to the floor. I have not seen to many like this, mostly, they all
the outside edge (see Fig A) so you have a little shelf on the inside
shower. Water lands directly on top of the hob and also runs down the
forcing itself into the grout joins on top of the hob. Once it gets
grout, even if you have a perfect waterproof membrane, the water is now
of the hob under the tiles and runs either back into the shower if
or it runs outside the hob into the bathroom behind the tiles. It can
into the floor, back up through the grout and onto the floor or it
around the outside of the hob until it gets to the door jamb or vanity
soaks into those. Hobs also create an excessive amount of internal
This is where concentrations of water also get forced into and
find a way through.
Fig A. Classic water
leaking over hob onto the floor under the tiles. A mother fell through
while brushing her daughters hair. Lucklily, he only fell 600mm or so.
This was the first sign they had a problem.
If you have a hob as described above
some of the things you
can do are: seal all internal comers, dig out the grout on top of the
seal with silicone. Look for ways that water falling down onto it can
way through. Make sure all tiles are clean first or your silicone won’t
A new screen sitting on the inside of the hob may work but you have
reduced the size of your shower and invested money in a new screen that
"Might" fix the problem. The Best way to address these problems is to
get rid of the hob and retile the whole base. You may be able to re-use
same screen as detailed later.
Taps and shower heads and other
penetrations in the shower can leak. The BCA (Building code of
states Taps should be sealed. It's not often I see them sealed. As part
renovations I always seal up to the taps, mixers and shower outlets and
waterproof membrane onto the tap body/pipe outlet.(19BP). In some cases
the tap spindle is recessed into the wall the best you can do is seal
silicone after the new spindles are installed. This is what would need
done to an existing shower. Remove the shower head, tap handles and
(Mixer handle and cover plate if mixers) and seal any gaps with
you need to change the washer (Valve) in the future you can cut it out
knife and re-seal it after the new valve is installed.
Mixers can be serviced from the very front so sealing these up well is
not a problem later.
Fig B.The different
stages of a mixer being sealed.
All shower heads are now are
restricted to at maximum flow
of 9 liters per minute. This puts extra pressure on the static pipes
valve to threaded join at the wall. You can also do a pressure test on
static section of pipe. Remove the shower head. seal a bung onto the
threaded pipe ($2 from Bunnings) and turn on the water. If there is a
the pipe between the valve and the outlet you may hear it. Turn the
and wait a few minutes. Release the bung and it should sound like you
beer. If you don’t hear that "Pssst" sound, go to the fridge and
crack an actual beer then call a plumber and check your insurance
may be covered.
As mentioned earlier,I have seen 2 separate occasions where
who installed the wall sheets in the bathroom put a nail through this
pipe. It has no pressure at the time so no alarm is raised. The pipe is
under full mains pressure when the shower is running so the leak is
just a drip. Both times it was on a timber floor home and the water
under the house and no one ever noticed it. The rotten wall and floor
frames still needed repairs.
The trick here if you are re-sheeting is to keep a bung on
the outlet and keep the cold water tap open so the pipe is under full
while nailing. If a nail hits it you will know it.
If you are not 100% confident with any of the above get a
plumber to come and check it. He will also have a pressure gauge he can
for a more accurate test.
Waterproof membranes are
the last line of defence to water leaking. Tiles and
grout are not waterproof as described above. Generally a tiled shower
will have a fall to the waste (drain) by means of sand and cement
screed is porous and lets water pretty much travel straight through it.
where the membrane should stop the water. Unfortunately it does not
the way we want. Modern membranes generally fail due to incorrect
Without turning this into a waterproofing lesson there needs to be
consideration for things like house movement, floor and wall frame
and drying times for single part liquid applied types and how the water
out and not just sit there for years and stink. (leak control flanges
Back in the seventies and early eighties a Galvenised tray
was sometimes installed as the waterproof barrier. These, over time
but did have a fairly good service life all thing considered.
Fig B, Rusted galvenised
shower tray after 35 years of duty.
If you have checked the above
scenarios to eliminate them
from the list and you still have a leak, then this leaves you with the
possibility that the membrane has
failed. Here’s how you check it.
Ensure the shower is dry and hasn't been used for 24 hours. Get some
glad wrap, fold it over a few times and cover the waste. (drain) Fold a
face washer and place it on the glad wrap and put some weight on it
that wont float to help seal
the waste up.
Now fill the shower floor with water from another source.
i.e. The garden hose. This will eliminate the plumbing from the list of
suspects. Fill it up to around half way up the hob and wait. Keep
adjacent rooms where you suspect water is going and see if you can
leaks. If you have carpet in the adjacent room get a set of pliars and
carpet near the wall and lift. It should come away from the smoothedge
of wood with little nails facing up) and you can then roll the
and check the floor. If the water level drops and you can't find a leak
under the house if you have a timber floor and look for water leaks. At
stage you should get water somewhere. If not your gladwrap seal might
leaking, try to reseal it with a heavier weight. If you have a more
recently built shower you could
have a leak control flange under the tiles and it could be going down
makes thing a little harder to check because the water could be soaking
the tiles and screed and soaking under the waist and into the drain
is what it is designed to do) if you keep losing water and it’s not
any where it is more than likely going down the leak control or waste.
If the water level stays that way for an hour or so and you can't find
any leaks, your
membrane is possibly OK so you need to go back and try some of the
If your membrane is leaking the best way to repair it is to
remove the screen and tiles, apply a new membrane and re-tile, re-fit
Fixing leaks without
removing tiles in my opinion is hit and
miss and at best, not a permanent repair. I have heard of people having
(for how long?) with this method but I have also repaired plenty of
that have had it done and failed soon after. Some clients say they got
back one or more times as a warranty call but just came to the
more permanent repair is required before the damage gets worse.
water detection meters that simply detect the presence of moisture to
look all scientific but you as the home owner know your shower is
because your carpet is wet and you called them. Do they really need a
moister meter to tell you your shower that gets wet every day is
What they do is use an epoxy
caulking and caulk up all the internal corners in the shower. Some
grout with epoxy grout as well. Epoxy is a terrific product and sticks
anything but has not flexibility. This can be successful so long as
doesn't move, however the fact is all houses move during different
times of the
year. The BCA states "All internal corners in wet areas where
2 different surfaces meet shall be caulked with a flexible sealant".
For a temporary repair that will be better that epoxy you could try
cleaning all the internal corners, scratch as much loose grout out as
even use a fine grinder to cut the grout without going to deep and
membrane further. Then re-grout with a quality grout or you could even
silicone to fill every join. Leave it to dry. Clean again and apply a
bead of silicone to all the internal corners. (Read the section on
hobs also). This will at least flex with your house and could buy you
time to save the money and get someone to repair it properly.
I suggested this to a young couple who just purchased their home and
they tried it on their bathroom that was looking a bit tired with great
success. They called me back after a couple of years and I renovated
the entire bathroom.
Ripping into it
and removing the tiles and hob is required if all of the above prove
ineffective. One further
warning to note. If your home was built before 1985 you may have asbestos wall sheets. Have a read about Asbestos Here.
If you have asbestos wall sheets then it is my opinion that you now
need to do a full renovation because the only way you can address the
asbestos is by removing all of it. You may find a tradsman who is not
informed about asbestos (there are many) to do the repair but you
will then place all of the occupants of your home and the tradesman at
I will run through the process of repairing a shower base
with some pictures. If you are handy and, have some basic tools you may
do some or all of the steps your self. If not, then this is what
you should expect to get when you hand over a wad of money. Any good
ceramic tiler should be able to do this for you but I will give you the
basic steps to make sure you are getting what you pay for.
Make sure you don't get someone who will just remove the screen,
waterproof over the tiles. Then lay more tiles over the tiles. I have
seen it done.
Fig. 1, Remove the screen carefully if you plan to
re-use it. The screen on this job was made wrong but that helps when
you want to re-use it. It is actuall the same size as the outside of
the hob (I didn't get a photo until after the screen was removed) so
providing it is high enough it can be re-installed closer to the floor
Fig. 2, The lower 2 rows of tiles need to be removed wall
sheets need to cut leaving some sheet to apply the membrane to cover
the join. Remove the hob and floor tiles.
Fig. 3, shows the timber frame starting to rot.
Fig. 1Fig. 2Fig. 3
Fig. 4, shows more rot further in. This will need to have timber blocks inserted to give the wall sheets something to fix to.
Fig .5, shows the vanity that soaked up some water. It was installed wrong also (below floor level)
Fig. 6, New wall sheets.
Fig. 4 Fig. 5Fig.6
Fig. 7 Aluminium angle on the floor the same colour as screen.
Waterproofing extends into the waste pipe and up the angle and walls.
The waste allows water to go around it and into the pipe.
Screed, floor and wall tiles. White was a close match and kept it on
the floor also as the tiles are unavailable after 20 years. The aluminium angle is a few mm higher than the floor tiles
Fig.9 Screen installed and a silicone bead seal the screen to the floor angle.
Fig. 7 Fig. 8 Fig. 9