_The Problem_
There are three things which will affect the plumbing system of the
small house; namely, the existence or non-existence of municipal
plumbing codes under which the structure is erected, the existence
or non-existence of a public sewer, and, finally, the type of
water-supply, whether it is public or private.
[Illustration]
If there are no plumbing codes to follow, it is sometimes possible to
save money on the plumbing; but unless the specifications are very
rigid, there is danger of poor work being installed. By saving money is
not meant installing cheap material, but eliminating certain features
which most plumbing codes require and which are not essential in
producing the best possible type of plumbing system. For example, in
most cities the ordinary traps which are required under each fixture to
prevent the sewer-gas from returning into the air of the house, after
the waste water has drained out, must be equipped with back-vent pipes
in order to eliminate dangers of siphonage. The cheap S trap (shaped
like an S turned on its side) without this back-venting will siphon
out, that is, lose its water-seal by atmospheric pressure pushing the
water out of the trap in its attempt to fill a vacuum created by the
discharge from a water-closet on the floor above. By back-venting
these traps, as shown on page 94, this danger of siphonage is
reduced, and, therefore, most codes have adopted this regulation
requiring back-venting. But to-day the market offers certain traps
which are claimed to be anti-siphonable and which do not require
this back-venting, with the consequent result of reducing the cost
of the equipment. Most plumbing codes have not changed their old
regulations, for many authorities do not yet believe in the possibility
of an anti-siphon trap, and so require the use of the back-venting
system. Consequently, wherever the small house is constructed within
jurisdiction of these laws, the plumbing will cost more than where
the anti-siphon trap can be used without the elaborate system of
back-venting.
Likewise, wherever there is a public sewer, the problem of sewage
disposal is simple and cheap; but if the house is not located near
any such public convenience, special methods must be employed for the
destruction of the waste matter. The best is the septic tank (see
illustration) with the small subsurface irrigation tile, through which
the partially purified material from the septic tank is distributed
under the ground for complete purification by air and bacteria. The
other method of disposal—pouring the sewage into a cesspool—is to be
deplored, unless there is possibility of an early construction of a
public sewer, and no drinking-water is secured from the premises.
[Illustration:—SMALL SEWAGE DISPOSAL PLANT—]
The third consideration which affects the plumbing system of the small
house is whether it can draw upon a public water-supply, or whether it
must secure its private supply from a well or a near-by stream or lake.
A private source of supply generally means the erection of a storage
tank. The best type of tank for this purpose is the pneumatic tank,
which is installed in the cellar, and not in the attic, as was the
old-fashioned tank. The water is pumped into this tank, and the air
which is in it is trapped, so that the more water that is pumped into
the tank, the more compressed becomes the air. This springlike cushion
of air gives enough pressure to force the water to any fixture in the
house.
[Illustration:—PLUMBING SYSTEM USING ANTI-SYPHON TRAPS—]
_Simplest Type of Drainage System_
On page 97 is represented the simplest type of drainage system that can
be installed in the small house, but since it uses anti-siphon traps
and no back-venting, it will not be possible to make use of it in all
cities or towns which have plumbing rules prohibiting it. The average
small house does not have room for more than one bath, a kitchen-sink,
a set of laundry-tubs, and a toilet for the servant, generally placed
in the cellar. For purposes of economy it is essential to place all
of these fixtures on the same soil-line, the main pipe which extends
vertically from the horizontal house-drain in the cellar up through the
roof. If the bathroom is so located that the vertical line which serves
its fixtures cannot serve the kitchen-sink or the laundry-tubs, then
a special waste-line or small vertical pipe draining fixtures other
than water-closets, must be carried up and through the roof, which is
extravagant of material. As this waste-line will be only 2 inches in
diameter, it is necessary to increase its diameter to 4 inches before
projecting it from the roof, since it may become clogged in the winter
with frost. But the main soil-line is 4 inches in diameter and needs
no increaser on it. The main house-drain is also made 4 inches in
diameter, and is generally laid under the cellar floor with a pitch
of ¼ inch to the foot. At the junction of the vertical soil-line with
it, and also at any other point where there is a marked change in
direction, the house-drain should be equipped with clean-out holes,
covered with brass screw-caps. Just where the house-drain leaves the
house, a house-trap is installed (see illustration), and back of this
an inlet for fresh air to permit the circulation of air in the system.
The foundations should be arched over the house-drain where it passes
through them, so that any settlement of the masonry will not come upon
the pipe and cause it to be broken.
The material of which the house-drain, soil-line, and waste-line are
made is usually cast-iron, and of a grade known as extra heavy. The
joints are the bell-and-spigot type, which are stuffed with oakum and
then closed tight with 12 ounces of fine, soft pig lead for each inch
in diameter of the pipe. Branches are usually of galvanized wrought
iron or lead, but lead should be limited in use in modern plumbing,
although the term plumbing originated from the Latin word for lead.
The common limitations upon the length of branches of lead pipe are:
8 feet for 1½-inch pipe, 5 feet for 2-inch pipe, 2 feet for 3-inch
pipe, 2 feet for 4-inch pipe. The parts of the branch pipes which are
visible are generally made of brass nickel-plated. The joints between
lead pipe and lead pipe, and between lead pipe and brass pipe, are made
by the common wiped joint. Joints between lead pipe and cast-iron pipe
are made by first wiping the lead pipe to a brass ferrule, a piece of
pipe in shape like a bell with the top cut off, and then inserting and
caulking this into the cast-iron pipe. The joints between wrought-iron
pipes are made with the screw joint, and between wrought-iron and cast
iron with the screw joint, by using connections of malleable cast-iron
which have been threaded.
The usual sizes for branch wastes from the fixtures are as follows: for
water-closets 4 inches, for bathroom-tubs 1½ inches, for lavatories
1½ inches, for kitchen-sinks 2 inches, for laundry-tubs 1½ inches,
and when in sets of three 2 inches. The size of the waste from the
bathroom-tub can be increased to 2 inches with great advantage, if the
additional slight expense is not objectionable.
The vertical soil-lines should be supported at each floor by metal
straps placed under the hub and fastened to the floor-joists. It is
very important to properly flash the base of the projecting portion
of the soil-line above the roof. Wherever the branch soil-line to the
water-closet is connected, a short TY connection may be employed in
order to avoid the projection of the parts of the pipe beyond the plane
of the ceiling in the floor below. However, no short TY connections
should be made in any horizontal pipes.
A very important economical consideration should be noted in laying
out the arrangement of the bathroom fixtures in this connection. The
horizontal branch soil-lines and waste-lines must be carried through
the floor construction, and they should be so arranged that they can
run parallel with the floor-joists; otherwise deep cuts will have to be
made in them. In the case of the branch soil-line it is essential to
place the water-closet as near to the main soil-stack as possible, for
with a 4-inch pipe the joists must be framed around it rather than be
cut, since so deep a gouge would weaken too much the strength of them. A
similar consideration must be given to the framing in stud partitions
which are bearing the loads of the floors above, for too deep cuts in
them, to allow for the passage of pipes, will weaken them greatly. In
this connection it ought to be noted that an ordinary 4-inch soil-pipe
cannot be carried in a stud partition made with 2 by 4 studs, since
the outer edges of the joints of the pipe will project beyond the face
of the plaster, and for this reason some convenient place should be
planned for them in closets, or 2 by 6 studs should be used in the
partition through which they are run.
_The More Complicated Back-Vent System_
The essential parts of the plumbing system remain the same as described
above, but each trap is considered to be siphonable, and must be
prevented from losing its water-seal by the use of back-venting pipes.
Whenever, then, there is an unusual amount of semi-vacuum created
in the pipes by the discharge of some fixture above, the outside
air-pressure can relieve it by passing through the back vents rather
than by forcing out the water-seal in the traps. The usual type of
trap employed is the modified S trap with the small TY connection to
give what is known as continuous venting. Formerly the vent was taken
off from the crown of the three-quarter-S trap, which was too near the
surface of the water-seal, causing excessive evaporation and danger of
clogging, but with the continuous system of venting, the waste-pipe
is a continuation of the vent-line, and the trap enters into its side
through a TY fitting, overcoming the disadvantage of the older system.
The size of traps should conform to the size of waste-pipes, and
usually the size of the branch vents is about the same size as the
waste-lines. However, there are special conditions where this varies.
For venting the water-closet trap, it should be noted that the vent is
not taken from the trap which is contained within the fixture itself,
but is taken from the upper side of the bend (usually of lead) where
the fixture is joined with the piping system, and is 2 inches in
diameter.
[Illustration: PLUMBING SYSTEM USING BACK-VENTING]
Where there are two fixtures, such as the lavatory and the bathtub,
with 1½-inch branch vents coming from the traps, these may be joined
into one main branch vent, which need not be more than 1½ inches in
diameter. The pitch of the branch vents entering into the main vent
should be at an angle of about 45 degrees, so that all rust scale will
drop down into the fixture outlet and be washed away.
The main vent, which runs parallel with the main soil-line, needs to
be only 2 inches in diameter, and should be branched in at the bottom
and the top to the main soil-line, as shown in the drawings. The
material of which both main vent and branch vent is made should be
galvanized-iron piping.
The fresh-air inlet, the house-trap, the clean-outs, and all other
parts of the system are the same as was shown for the simpler method of
plumbing.
_Rain-Water Drainage_
The small house need not drain off its roof-water into the plumbing
system, if the plumbing code does not require it. The simplest and
easiest method to dispose of it is to collect the water in gutters,
lead it down the waterspouts into pipes which terminate in a dry well
in the ground. Small roofs over porches and back doors need not even
have the leaders, but spill the roof-water out onto the ground, where a
stone has been placed to prevent the undermining of the surface of the
lawn by the wearing action of the water stream.
In outlying city districts where the sewers have not yet been installed
it is customary to carry the roof-water in pipes below the level of the
sidewalk to the gutters of the street or to a leaching cesspool which
is independent of the cesspool used for sewage disposal, and which is
practically the same thing as a dry well, for the bottom is made with
gravel through which the rain-water seeps off into the surrounding soil.
Wherever the rain-leaders must be connected to the drainage system of
the house, the sheet-metal leaders are inserted into cast-iron pipes
called shoes at the base, which in turn are trapped on the inside
of the cellar wall and connected with the house-drain. It is always
best to try to trap a group of leaders to one trap rather than use a
separate trap for each leader.
_Tests and Precautions_
There is nothing very complicated in the plumbing system of the small
house. Certain sanitary precautions should be observed in arranging
lines, however. For example, the termination of the main soil-line
should not occur near a dormer or other window, nor should the
termination of the fresh-air inlet be located in the cellar wall under
a door or window. The system when completed in the roughed-in form
should be tested for leakage by filling it with water, and when all
the fixtures are connected and every part of the system is supposed to
be in working order, either the peppermint or the smoke test should
be used to detect any further possible leakage. The peppermint test
consists in pouring hot water and 2 ounces of oil of peppermint into
the top of the system from the roof, after all the fixture traps have
been filled with water, and then detecting with the nose where the
leaks are. If the smoke test is employed, a smoke machine is best. Old
oily rags and tar paper are burned in the machine, which has its flue
connected with the fresh-air inlet, and the smoke is pumped through
the system until it appears escaping from the soil-line extension on
the roof. If there are any leaks, the odor and the smoke stain will
attract attention to them, and if the water-closet traps in the bowls
are defective, the yellow stain of the smoke will make it very evident.
_Refrigerator Connections_
The drainage from the refrigerator should never be directly connected
with the drainage system of the house. If the plumbing code requires
any connection at all, the usual arrangement is to drip the ice-box
water into a lead-lined tray which has a pipe at least 1¼ inches in
diameter that carries the water down to the laundry-tubs in the cellar
and spills it into them. On the other hand, if there are no plumbing
regulations, it is best to drain this water off into a small hole in
the ground into which has been thrown gravel, and this will permit the
water to soak into the surrounding soil.
_Water-Supply Pipes_
If there is a city supply of water, the small house should have a
main supply-line from the water-main in the street of at least ¾-inch
diameter, but this does not give the service that a larger pipe, say a
1¼-inch pipe, does, for often with the smaller pipe, if the water is
being drawn in the kitchen, none will be secured from the faucets in
the second-floor bathroom. The kitchen-sink should have a service pipe
of at least ¾ inch, the tubs the same, and the lavatory ½ inch.
All service-lines should be compact and as direct as possible, and long
horizontal runs under floors should be avoided. Hot-water supply-lines
should be kept at least 6 inches from cold-water lines. There should
be a shut-off at the entrance of the supply-line to the house, at the
base of all vertical risers, and under each fixture. To avoid water
hammer, it is best to take all faucets off the sides of the termination
of pipes, rather than from the ends, for in this way an air-cushion can
form, relieving the pounding action of the water in the pipes.
Supply-lines should never be run in the corners of buildings where they
are in danger of freezing, and they should be kept out of the exterior
walls of houses as much as possible for the same reasons. The packing
of pipes where they pass through the floors will often prevent freezing
caused by cold drafts around them.
_Hot-Water Supply_
[Illustration]
It is generally accepted to-day that the most convenient method of
securing hot water in the small house is with the instantaneous type of
gas-heater, connected with a boiler for storage purposes, but capable
of delivering water directly into the pipes without passage through
the boiler, when a sudden demand is made upon it. These gas-heaters
have a system of Bunsen-burners which heat the water as it passes
through a series of copper coils, and generally the water is warmed to
a temperature of 100 degrees in one passage. They are automatically
controlled, so that when the temperature of the water goes below a
certain fixed standard the gas-burner is lighted by a small pilot-light
until the proper temperature is reached, when it is shut off again.
Although these heaters are arranged to deliver hot water directly from
the coils, yet if they had no boiler to store up the water, much larger
heaters would be required than necessary. For storage purposes, then, a
40-gallon boiler is satisfactory for a residence with one bath and one
kitchen, and if there are two baths a 50-gallon boiler is needed. The
usual location of the boiler and heater is in the cellar.
However, where there is no gas to be used, the coal-heater must
be employed—either the tank-heater or the water-back in the
kitchen-range. The latter was the usual old-fashioned method of heating
the water, and the boiler was located alongside of the kitchen-range.
The size of the water-back was proportioned on the basis of 2 square
inches of heating surface to each gallon storage capacity in the
boiler. The tank-heater is a special coal-burning stove, designed to
serve as an iron-warmer and a water-heater, being usually placed in the
laundry in the cellar. Another method of securing hot water, which is
not recommended, is to place heating coils in the furnace; it obstructs
the fire-pot, chills the fire, overheats the water in cold weather and
underheats it in warm weather, and does not operate at all during the
summer.
_Fixtures_
The modern bathroom fixture may be made of one of three materials: true
porcelain, earthenware, or enamelled-iron. The true porcelain fixtures
are the heaviest, the most durable, and the most expensive. The
material is non-absorbent and white in color, and the surface presents
a gloss which is in reality a form of glass. When it is chipped the
fracture shows the material below as white, and a drop of ink will not
be absorbed by it.
In imitation of the porcelain fixtures are made earthenware ones, but
which are in no way to be compared to the true porcelain, although a
casual glance at them would lead one to think that they were porcelain
fixtures. However, a chip from the surface will reveal the yellow
and porous texture of the earthenware below the glazed surface. The
glossy white surface in time stains and becomes covered with small
hair-cracks, unlike the porcelain fixtures, and for this reason they
are not as sanitary nor as durable. They are cheaper than the true
porcelain fixtures, but this material should be avoided in water-closet
bowls, but is admissible for use in tubs and lavatories.
The enamelled-iron fixtures are considered by most to be superior to
the earthenware fixtures, since they do not craze, are lighter, and
generally more durable. The quality of this ware can be judged by the
absence of roughness, blisters, bubbles, and spots, and freedom from
hair-cracks and peeling. Bathtubs of the modern type made of enamelled
iron have the rich appearance of porcelain fixtures, since the sides
are rolled over and covered with enamel, unlike the old-fashioned
types, which had the interiors lined with the enamel and the exteriors
painted with white paint.
The mechanical operation of the various fixtures is so well
standardized that not much choice is given between the catalogue of
one firm and another. The best type of water-closets are the siphon,
the siphon-jet, and the converging jets, the latter being a more
modern development, which has eliminated the noise of the siphon
action and yet which accomplishes a quick and rapid flushing action.
The lavatories which are most commonly specified are of the pedestal
type, although the modern tendency in sanitary bathroom design is to
eliminate as far as possible all junction of fixtures with the floor,
for it is here that dirt and stains develop. Such arrangements carried
to the extreme would require a sunk bathtub, a lavatory without legs,
and special compartment for the water-closet, but this would be absurd
for the small house. However, the built-in bathtub is far superior to
the old-fashioned tub which stood upon legs, and under which all manner
of dirt could collect.
We often hear the remark that no wonder the cost of living to-day
is so much higher than it was with our ancestors, who knew nothing
about the clean, tile-lined bathrooms with porcelain tubs, white and
glistening lavatories with all the cold and hot water needed, while
in the old days the wooden tub, set up in the kitchen near the range,
was good enough for the Saturday-night bath, and the tin pan, filled
under the hand-pump outside on the back porch, was good enough to wash
the hands in each morning. But although the modern bathroom and the
modern plumbing system is an economic burden to the small house, it is
doubtful if we shall ever see the day when it is abolished in order to
cut down on the cost.