Whether you're installing a better-flushing toilet or resetting the old one after remodeling, these tips will help you do it faster and with fewer problems.
By the DIY experts of The Family Handyman Magazine:March 2009
If you’re buying a new toilet, you
need to know the “rough-in” measurement
of the old one. For the vast
majority of toilets, the waste pipe is
centered about 12 in. from the wall.
But with a few models, that measurement
is 10 in. or 14
in. To check the
rough-in, just measure
from the wall to
the toilet’s hold-down
bolts. If that
the thickness of the
approximately 12 in.,
toilet shopping will
be a bit harder. Most
home centers carry
only one or two
10-in. models and no
14-in. models. If you
have to special-order a toilet, be prepared
to spend much more.
If there’s a door near the toilet,
also measure how far the bowl protrudes
from the wall. If you replace a
standard bowl with an “elongated”
model, the door may not close.
Some metal toilet bolts have a yellowish
zinc coating that makes
them look like brass. So check the
label and make sure you're getting
brass bolts and nuts. They
won't rust away and they're easier
to cut off later. If you need to reanchor
the toilet flange,
buy stainless steel screws. They
won't corrode like steel or break off
like brass while you’re driving
Don't be surprised if the old nuts that hold the toilet in place won't budge. Years of corrosion can weld them to their bolts. In that case, a hacksaw blade is the solution. You can buy a “close quarters” blade holder at home centers and hardware stores, or just wrap a bare blade with a rag or duct tape. Most toilet bolts and nuts are brass, so they're easy to cut. If the bolt spins, grab it with locking pliers as you cut.
Setting a toilet onto the new bolts can be the most frustrating part of the whole
installation. The bolts slip and tip as you're straining to align them with the
holes in the toilet. And each time you miss, you risk crushing or shifting the wax
ring. The plastic slip-on washers sometimes included with bolts help, but they
still allow the bolts to move. The best approach is to buy a second set of nuts and
washers so you can lock the bolts in place before you set the toilet. To make sure
they're in the correct position, set the toilet and check its height and position.
Then lift it off and add the wax ring. To make the bolts easier to find, mark their
locations with masking tape.
Loose flanges are usually the
result of wood rot. The flange
screws simply won't hold in the
soft, decayed subfloor. The best
solution depends on the extent of
the rot. If the rot is only under the
flange, use an ear-type repair ring. The ears let you drive screws
into firm wood farther away from
the flange. Before you install this
kind of ring, hold it up to the drain
horn on the underside of the toilet.
You may have to cut off a couple
of ears to make it work with your
toilet. If the rot extends well
beyond the flange, you'll have to
replace a section of the subfloor.
Plastic flanges often bend or break, but
that's an easy fix. Just screw a stainless steel
repair ring over the plastic flange with
at least four 1-1/2-in. stainless steel screws.
Consider doing this even if the plastic flange
is in good shape—it's cheap insurance
against future trouble. The repair ring raises
the flange by about 1/4 in. So before you
install the ring, set it on the flange and set
your toilet over it to make sure it fits.
Steel flanges attached to plastic hubs can
rust away. The easiest solution is a two-part
ring that locks onto the plastic just like the
old one. To cut away the old flange, use a
hacksaw blade or an angle grinder with a
metal-cutting wheel. The repair
flange is available at some
home centers, at plumbing supply stores or online (search for “bay flange”).
Cast iron flanges can break or corrode. If the flange is in bad
shape, you can add a brass repair ring similar to the stainless steel ring shown
above or install a plastic flange that
slips inside. If necessary, break away the cast
iron flange with a cold chisel. Home centers
carry one or two slip-in flanges. For a wider
variety, search online for “replacement toilet
If only the bolt slot of the cast iron flange is damaged, slip a repair bracket
under the flange.
A rock-solid toilet flange is the key
to a leak-free toilet. The flange is
the only thing anchoring the toilet
to the floor. If the flange is loose
or damaged, the toilet will rock.
And a rocking toilet will distort the
wax ring and cause leaks. So be
sure to scrape off the old wax ring
and inspect the flange. Here are
some solutions for broken, corroded
or loose flanges.
A toilet that rocks on an uneven floor will eventually break the wax ring seal and
leak. So check for wobbles after you've set the toilet in place and loosely tightened
the nuts. For slight wobbles, slip coins or stainless steel washers into the
gaps under the toilet. Don't use regular steel washers, which might rust and stain
the floor. For larger gaps, use shims. There are plastic shims made especially for
toilets, but plastic construction shims like the ones shown here work just as
well. When you've eliminated the wobble, tighten the nuts, cut off the shims
and caulk around the toilet base. A toilet set on thick vinyl flooring can loosen
as the vinyl compresses. In that case, just retighten the nuts a few days after
When you set the toilet in place, you
have to squish the wax ring until the
toilet settles to the floor. DON'T force
the toilet down by tightening the nuts
on the toilet bolts—that might crack the
porcelain base. Instead, sit on the
toilet backward with your weight
centered over the wax ring. Then
wiggle around a bit until the toilet reaches the
floor. But don't go crazy. You want
to drive the toilet straight down
with minimal twisting or shifting
of it from side to side. When the
toilet reaches the floor, snug down
the toilet bolt nuts.
Do yourself a favor and buy a
flexible water supply line.
They're a lot easier to install than
stiff metal or plastic tubing. Be
sure to get one that's covered with
stainless steel mesh. For a
good seal, hold the hose so it aims
straight into the shutoff or fill
valve while you're screwing on
the connectors. Make them handtight,
then add another quarter
turn with pliers. Connections that
are too tight can actually cause
leaks or spin the fill valve inside
the tank. Check for leaks and
tighten them a bit more if needed.
To make positioning a toilet
easier, new toilet bolts are extra
long. That means you have to
cut off the protruding ends
later with a hacksaw. But first
connect the water line, flush
the toilet a couple of times and
check for leaks. Leaving the
bolts uncut until you’ve done
these final checks lets you easily
remove and reset the toilet
if you find any problems.
After cutting, double-check
the bolts for tightness. Cutting often loosens the nuts a bit.
Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.
Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.
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