Find That Leak
Discovering you have a leak in your bathroom is not nearly as
difficult as finding where that leak is. Here are a few tips to start your
It happens one day while you are absorbed in a daydream---staring absently at
your ceiling you notice it--a watermark. Something is leaking from your
upstairs bathroom. Avid do-it-yourselfers tend to pull out the caulking gun
and re-caulk the entire bathroom. This usually creates quite a mess, and
only occasionally solves the problem. The other extreme is calling in a
contractor to fix the leak, which will probably solve the problem, but comes
with a pricey bill.
The best thing for a do-it-yourselfer to do is to try to recreate the leak.
First, begin checking the shower drain line to see if that is the culprit.
Piping is rarely the cause of the problem, but since it is easy to check you
can at least rule out that problem. Pour several gallons of water down the
drain and see if the leak begins again. Be sure not to spill the water on
any part of the tub. Use of a garden hose or a funnel may be helpful during
this step. If the spot on your ceiling isn't leaking at this point, that's a
good sign, meaning your piping is intact.
The next step is to check the chrome flange in the bottom of the tub that
connects the shower body to the drainpipe. Pour water around the flange so
that it is completely immersed. Generally, the flange is screwed into the
drainpipe in a bed of caulk. The caulk covers the slight recess around the
drain, which is where the flange will sit flush with the shower floor once
it's tightened down. If this caulking cracks, water can drain through the
shower floor and outside of the drain line, which can rot out the subflooring
supporting the shower base. If your leak occurs here, you can easily fix
this problem by unscrewing the flange, clearing out the old caulk, laying a
bed of silicone caulk, and reinstalling the flange.
One trick to remember is to use enough caulk so that extra oozes out on all
sides of the flange as you tighten the fitting. When the caulk dries, strip
away the excess.
If you still haven't found your leak, the odds are that it is probably coming
from the seams between the base of the shower and the wall. To test this,
flood these seams. If you can reproduce the leak, caulking may help.
It's worth a try before you tackle the big (and expensive) job of replacing a
shower base, or the pan under a tiled base. You might be able to stop a leak
by scraping out the old grout or caulk and installing new material.
And if you are still at a loss for locating the leak, try one more test.
Douse the walls with spray from the showerhead, including the door or the
side of the tub where the shower curtain hangs. This test may indicate that
water is not leaking through the shower floor at all, but actually outside of
the stall or tub. Water can seep through the vulnerable seam where the
shower base meets the bathroom floor. Grout, because it is not flexible,
does not last long in seams between a shower or tub base and the walls or the
floor. Grout requires rigid support to keep from cracking, and these seams
do not stay rigid all of the time-they flex as you step in and out of the
shower, or fill the tub with water. You can prevent these problems by
grouting the tiles up to these seams, and then filling the final seam with a
flexible caulk, such as silicone.
Once that leak is found and repaired, you can get back to staring at your
ceiling. If you're really particular, though, you may have some repainting
to do before your daydreaming can continue in earnest.
Sources: Mike McClintock, The Washington Post