Walk-In Bathtubs

Walk-In Tubs are often intended to replace regular bathtubs. These
fiberglass units permit both showering and bathing, much like
traditional bathtubs. But there are two major advantages that tubs
with doors have over traditional bathtubs:

•        The bather sits upright, on a built-in seat, eliminating the
challenges of having to perform a deep squat to sit on the tub
bottom and then having to somehow stand up again to get out of the
•        Stepping into, and out of, the tub is much easier because you
only have to raise your foot about 6” to pass through the door.

Many models have air bubbling systems that act as a “hydro-
therapy” message.


Commonly, an existing bathtub is removed and a walk-in unit
installed in its place.  Prepare for this occasion by reading the
section on Demolition.

The existing tub faucet, more likely than not, will not be positioned
correctly for the new walk-in tub.  These units stand 40” to 42” above
the bathroom floor, and thus usually cover over the existing faucet
location.  Normally, a new bathtub faucet is installed.  While any type
or style of tub faucet can be used in theory, in practice it is usually
more economical to use a faucet set-up that is attached directly to
the tub body.

The tub drain attaches to the waste plumbing that serviced the
original bathtub.

Walk-in tubs that have electrical components, such as air bubblers,
require a source of electrical power.  Because the power
requirement of the equipment is so low, electricity can often be
“borrowed” from nearby circuits and passed through a ground fault
protected receptacle.

Matching wall panels placed on each of the three walls of the typical
bathtub alcove complete the installation.  The dimensions of walk-in
tubs and existing tubs are never exactly identical, and removing the
original tub always causes some amount of localized damage.  The
wall panels facilitate the walk-in tub installation by adapting the new
tub to the size of the space it is filling, and by covering any damage
caused by process.

Points to Consider

While walk –in bathtubs are an excellent solution to a nettlesome
problem, there are some important considerations that you will
probably never see addressed anywhere but here.  None of these
issues are necessarily show stoppers in-and-of themselves, and,
they can all be mitigated.

BUT, you might want to think about . . .

Hot water tank capacity – A hot water tank with a 50 gallon
capacity is the absolute minimum size that will provide sufficient hot
water for a bath.  A larger tank, or a second tank, is strongly

These tubs consume large amounts of water.  A tub with no person
in it, filled to the overflow line, holds 85 gallons.  It takes about 60
gallons to get above the knees of a person sitting in the seat, and
about 70 gallons to get half-way up the abdomen.   That’s a lot of hot
water.  A 50 gallon hot water tank is hard pressed to meet this

What ends up happening is that the water temperature coming out of
the tub spout starts out fine, but turns luke warm, and then plain
cold, before the bath water has reached its desired level.  The
bather, meanwhile, is sitting in their skin feeling the temperature drop.

Faucet Capacity – For bathing (as opposed to showering), a
large caliber faucet system is desirable.  Typical run-of-the-mill bath
faucets are designed to attach to ½” water pipes.  Water saver
faucets restrict the rate of flow even more.  Water delivered through
these apertures  takes a long, long, long time to fill the walk-in
bathtub to a bathing level.

The bather, meanwhile, is sitting in their skin feeling the water creep
slowly higher.

An alternative to larger caliber faucets is to simply add a second
faucet set-up.  While this may be a little out of the ordinary, the
enhanced speed of filling is certain to be appreciated.  When
combined with a second hot water tank, this approach actually
makes sense.

Drain Capacity – Typical bathtub drains are plumbed with pipes
1-1/2” diameter.  It take about 4 minutes and 40 seconds for 70
gallons to drain through a 1-1/2” hole, without any pipes attached to
slow the rate down.

The bather, meanwhile, is sitting in their skin, waiting for the tub to
drain so they can open the door and get out.

Converting the tub drain and its connecting pipes to 2” diameter will
almost double the rate of flow.  The ease of doing this, however,
depends on your house plumbing.