LAYING TERRA-COTTA AND MAKING CONNECTIONS TO PUBLIC SEWERS. WATER
CONNECTIONS TO MAINS IN STREETS
TERRA-COTTA PIPE
One of the first pieces of work which a plumber is called upon to
do, when building operations commence, is to run in the terra-cotta
sewer from the street sewer into the foundation wall.
[Illustration: FIG. 35.--Connection of house sewer to main sewer.]
When the street sewer is laid, Y-branches are left every few feet.
A record of the branches and their distance from the manhole is
kept generally in the Department of Sewers or Public Works.
Therefore, the exact measurement of any branch can be obtained and
the branch found by digging down to the depth of the sewer. A
branch should be chosen so that the pipe can be laid with a pitch,
the same way as the main sewer pitches. This can be done by getting
the measurements of two of these branches and choosing the one that
will serve best. When there is a brick sewer in the street and no
branches left out, the sewer must be tapped wherever the house
sewer requires it (see Fig. 35).
DIGGING TRENCHES.--After the measurements and location of the house
sewer and sewer branches are properly located, the digging of the
trench is started. The methods employed to dig the trench vary
according to the nature of the ground, that is, whether it is sand,
rock, or wet ground. A line should be struck from sewer to
foundation wall to insure a straight trench.
[Illustration: FIG. 36.--Laying of plank for trench dug in sandy
ground.]
SANDY GROUND.--If the ground is sandy, the sides of the trench will
have to be sheathed or planked and the planks braced so as to
prevent the bank caving in. As the trench is dug deeper, the planks
are driven down. When the trench is very deep, a second row of
planking is necessary. The planks must be kept well down to the
bottom of the trench and close together, otherwise the sand will
run in. It is well to test the planking as progress is made by
tamping the sand on the bank side of the planks.
GRAVEL.--Where the ground is mostly gravel and well packed, the
above method of planking is unnecessary. The bank should have a few
stringers and braces to support it. When only a few planks are used
the term "corduroy the bank" is used (see Fig. 37).
[Illustration: FIG. 37.--Arrangement of plank for gravel.]
ROCK.--Where rock is encountered, blasting is resorted to. The
plumber should not attempt to handle a job requiring the use of
powder. It is dangerous in the hands of a person not used to
handling it and the work should be sublet.
A sketch of the two methods above for planking trenches is given
and a little study will make them clear.
LAYING OF PIPE
The pipe should be laid on the bottom of the trench to a pitch of
at least 1/4 inch per foot fall. In laying, the start should be
made at the street sewer with hubs of pipe toward the building. The
trench should be dug within a few inches of the bottom of the
pipe, then as the pipe is laid the exact depth is dug out, the
surplus dirt being thrown on the pipe already laid. The body length
of pipe should be on solid foundation. A space dug out for each hub
as shown in Fig. 38 allows for this, also allows for the proper
cementing of joints. To get the proper pitch of pipe, take for
example 1/4 inch per foot, a level 2 feet long with a piece of wood
or metal on one end 1/2 inch thick will answer. The end with the
1/2-inch piece on should be on the lower hub and the other end
resting on the hub of the pipe about to be put in place. When the
bubble shows level, then the pipe has the 1/4-inch fall per foot.
If a tile trap is used, it should be laid level, otherwise the seal
will be weakened or entirely broken.
[Illustration: FIG. 38.--Laying terra-cotta pipe.]
CUTTING.--The cutting of tile is not difficult, but must be done
carefully or the pipe will crack or a piece will be broken out,
thus making the pipe worthless. To cut tile or terra-cotta pipe,
stand the pipe on end with the hub down, fill the pipe with sand to
the point of cutting. With a sharp chisel and hammer cut around the
pipe two or three times and the pipe will crack around practically
straight.
CEMENTING.--If the pipe is free from cracks, the only possible way
roots can get into the inside of terra-cotta pipe is through the
cement joint. There are two ways of making these joints. Both ways
are explained below and are used today on terra-cotta work.
_First._--The bottom of the hub of pipe in place is filled with
cement and the straight end of the next piece of pipe is laid in
place, then more cement is placed into the hub until the space
between the hub and the pipe is filled. In a trench, a trowel is
rather unhandy to work with, while the hands can be used to better
advantage. The cement can be forced into place with the hands and
then surfaced with a trowel. The rest of the operation is to swab
out the inside joint to remove any cement that perchance was forced
through the joint (see Fig. 39). The cement used should be 1/2
cement and 1/2 clean sharp sand.
_Second._--Half of the space between the hub and the pipe is first
packed with oakum and then the other half filled with cement of the
same proportions as that used above.
[Illustration: FIG. 39.--Showing use of the swab.]
LAYING PIPE IN TUNNELS
[Illustration: FIG. 40.--Pushing pipe through tunnel.]
If the pipe must be run through a tunnel and there are perhaps
three or four joints that cannot be reached, they should be put
into place as follows: The pipe should be laid in the trench from
the sewer in the street as far as the tunnel, then start at the
other end of the tunnel. Lay the first piece of pipe on a board,
lengthwise with the board, nail two cleats in the shape of a >
(Fig. 40) for the pipe to rest in; push this pipe and board into
the tunnel and then cement into its hub a second piece; push the
two pieces in 2 feet, cement a third length into the second piece
and push the three pieces along 2 feet. A workman can be on the
sewer side of the tunnel and receive the end of the pipe as it is
pushed through the tunnel, and steer the pipe into the hub. The
joints in the tunnel will not be as secure as those outside. This
explains how pipe is run through a tunnel.
CONNECTING.--The proper method of connecting the house sewer with
the street sewer is shown in Fig. 35. The connection should be made
above the spring of the arch. The pipe should extend well into the
sewer so the sewage will discharge into water and not drop on
sides.
INSERTING.--To insert a tee in a line of pipe already laid, pursue
the following method (see Fig. 41): Cut or break out one joint,
preserve the bottom of the hub of pipe that is in. Cut away the top
of the hub on the pipe to be inserted, then place the pipe in
position and turn around until the part of the hub on the piece
inserted is on the bottom. The bottom part of the pipes now will
have a hub to receive the cement. The top part will have to be
cemented carefully, as it is within easy access. This can be done
without difficulty.
[Illustration: FIG. 41.--Inserting length of pipe.]
While laying the pipe a stopper is used to prevent the sewer gases
and foul odors from escaping. This stopper sometimes is of tile,
sometimes a plug of paper or burlap. This stopper is sometimes
cemented in by inexperienced men and the trouble created can only
be guessed at. If a stopper is used, the workman must see that it
is taken out.
REFILLING.--After the pipe is laid and cemented, it should be
covered and allowed to stand 24 hours to give the cement time to
harden. The dirt should then be thrown in and settled by means of a
tamper or by flooding with water. The planks should not be taken
out until the trench is well filled. To pull the plank, a chain or
shoe and lever will have to be used. Where the tunnels are, dirt
will have to be rammed in with a long rammer, care being taken not
to disturb the pipe. If the refill is not well rammed and tamped,
the trench will settle and cause a bad depression in the street
surface.
TERRA-COTTA PIPE.--Terra-cotta pipe should be straight, free from
fire cracks, and salt-glazed. The inside of the hub and outside of
the plain end should not be glazed. This allows the cement to take
hold.
TABLE OF STANDARD TERRA-COTTA PIPE
------+------------+-----------------+----------+--------------
Size | Thickness, | Weight per ft., | Depth of | Annular space
| inches | pounds | socket |
------+------------+-----------------+----------+--------------
3 | 1/2 | 7 | 1-1/2 | 1/4
4 | 1/2 | 9 | 1-5/8 | 3/8
5 | 5/8 | 12 | 1-3/4 | 3/8
6 | 5/8 | 15 | 1-7/8 | 3/8
8 | 3/4 | 23 | 2 | 3/8
9 | 13/16 | 23 | 2 | 3/8
10 | 7/8 | 35 | 2-1/8 | 3/8
12 | 1 | 45 | 2-1/4 | 1/2
15 | 1-1/8 | 60 | 2-1/2 | 1/2
18 | 1-1/4 | 85 | 2-3/4 | 1/2
20 | 1-3/8 | 100 | 3 | 1/2
------+------------+-----------------+----------+--------------
Terra-cotta pipe should not be permitted in filled-in ground.
Roots of trees find their way into the pipe through cracks or
cement joints. When the roots get inside of the pipe they grow
until the pipe is stopped up. As the roots cannot be forced or
wired out, the sewer must be relaid. The writer has seen a solid
mass of roots 10 feet long taken out of a tile sewer.
In case terra-cotta is laid in filled-in ground, there is only one
way to insure the pipe from breaking. The pipe should be laid on
planks. Then, if the ground settles, the pipe will not be broken.
WATER CONNECTION AND SERVICE
TAPPING MAIN.--The water service for a building is put in at the
same time as the sewer is connected and run into the house. For a
1-1/4-service pipe a 1/2-inch tap is furnished. The water company
taps the main, at the expense of the plumber, and inserts a
corporation cock.
[Illustration: FIG. 42.--Showing water main and sewer in same
ditch.]
DIGGING TRENCH.--The trench for the water main should be dug at
least 4-1/2 feet deep or below frost level and the trench should be
kept straight. When the sewer is put in at the same time, one side
of the sewer trench can be cut out after it is filled up to the
level of the water main. The water pipe can then be laid on this
shelf at least 2 feet away from the original trench of sewer.
Sometimes the surface of the ground must not be disturbed. In this
case small holes are dug and the pipe is pushed through or driven
through under that portion not dug. These places are often
tunnelled (see Fig. 42).
In digging in city streets, care should be taken not to destroy any
of the numerous pipes encountered.
LAYING PIPE
The trench should be dug straight out from the house so the pipe
can be laid and the main tapped straight out from the building. The
water companies keep a record of these taps so that in case of
trouble the street can be opened and the water shut off. In laying
the water service, the pipe from the curb to the main should be
laid first. This takes in all the pipe in the street. At the main
there is a shut-off in the tap. Another stop with T or wheel handle
must be placed just inside the curb line. This is called a curb
cock (see Fig. 43). One trench either outside or inside of the curb
should be at least 15 feet long so that a full length of pipe can
be laid in the trench. It is generally impossible to open a trench
the full length the pipe is to be run. A trench 10 feet long is
dug, then 8 feet left, and another 10- or 8-foot trench is dug and
the two are connected with a small tunnel and pipe pushed through.
When the pipe has been put in place between the curb and main, the
water is turned on and the pipe flushed out. The valve at the curb
should now be shut off, and if there are any leaks they will show.
The street part is now ready to fill in. At this point Fig. 43
should be studied. Note the piece of lead attached to the pipe and
corporation cock. This piece of lead should be extra heavy and
always laid in place the shape of the letter S or goose neck. In
case the street should settle, this piece of lead will allow for
it. These "lead connections" or "goose necks" are made as follows:
3 ft. of 5/8 lead pipe; 1-inch brass solder nipple (wiped on); one
brass corporation cock coupling (wiped on).
LAYING PIPE.--This lead connection can be screwed on the pipe after
the pipe is laid, then bent and coupled on the main with the
coupling.
[Illustration: FIG. 43.--Water main from street to foundation
wall.]
After the pipe has been tested as far as the curb, the trench in
the street can be filled as described later. The pipe from the curb
to the building can now be laid. If necessary to push the pipe
through a tunnel, the end of the pipe should first be capped. Start
by screwing a length in the curb cock. If the other end of the pipe
comes in a tunnel an additional length must be put on before
putting in place so that an end will come in the open trench. When
the building is reached and before the stop cock is put on, the
valve at the curb should be opened full and the pipe flushed out.
The valve can then be put on and water turned on to test the pipe.
SETTING CURB BOX.--A cast-iron box, adjustable length, with cover
should extend from the curb cock to the surface. This makes it
possible with a long rod to control the water service into the
building. To set a curb box some flat stones should be laid around
the curb cock and the box set on these stones. Then the space
around the box and pipe should be closed in with brick or other
covering to keep the sand from washing in on the curb cock. The box
should be adjusted for height and then held in place by placing the
curb key rod in place and holding the rod and box while the trench
is filled. The refill should be tamped evenly on all sides of the
box.
REFILL.--In refilling the trench around the corporation cock and
goose neck, the greatest care should be taken. The writer has seen
cases when indifferent workmen have tossed heavy stones in the
ditch and broken off the corporation cock or destroyed the goose
neck. After the pipe is covered with 18 inches of refill and
tunnels have been filled, water can be run in the trench and will
settle the refill.
There are a number of special points concerning water services and
taps at mains that should not be overlooked. Take for example a
water service pipe which must be run through ground where
electricity is escaping under trolley tracks, around power houses,
etc. The electricity will enter the pipe and wherever it leaves the
pipe a hole is burned. The surface of the pipe in a short time will
be full of small pith marks and will soon leak. A good way to add
to the life of the pipe under these conditions is to make a star of
copper and solder it on to the pipe in the street. Another piece of
copper should be put on the pipe near the building. The electricity
will leave the pipe by way of the points on the star. This method
may not be a cure for electrolysis, but will add to the life of the
pipe. Another method employed is to put the pipe in the center of a
square box, then fill the box with hot pitch. When this is hardened
the pipe will have a covering that will keep out any moisture and
bar electricity to a marked degree.
MATERIALS USED.--Galvanized steel pipe does not last under ground.
Galvanized iron, heavy lead, and brass are used. Wooden pipes were
once used and stood years of service. No service smaller than 1-1/4
should be used.
When the water service pipe passes through the foundation wall, the
pipe should not be built in, but a small arch should be built over
the pipe or a piece of XX cast-iron pipe can be used as a sleeve
(Fig. 44).
[Illustration: FIG. 44.--Free space around pipe passing through
wall.]
POINTS TO REMEMBER.--
SEWER INSTALLATION
_First_, select good sound pipe and fittings.
_Second_, locate branch connection in street sewer.
_Third_, lay out run of house sewer.
_Fourth_, take out necessary permits from departments of sewer.
_Fifth_, dig trench in the street, then into the house.
_Sixth_, lay pipe and cement joints.
_Seventh_, refill trench, tamping every foot.
_Eighth_, cast-iron pipe for sewer is found under another heading.
WATER SERVICE
_First_, take out necessary permits.
_Second_, list material and deliver to job.
_Third_, lay out and dig trench.
_Fourth_, have main tapped.
_Fifth_, lay pipe to curb and test.
_Sixth_, fill in street trench.
_Seventh_, lay pipe into building and test.
_Eighth_, set curb box.
_Ninth_, refill trench.
_Tenth_, thoroughly consider any special conditions.
_Street Sewer._--Large pipe in streets to receive all soil and
waste from buildings.
_House Sewer._--Conveys sewage from building to street sewer,
extends from foundation wall to sewer.
_Street Main._--Water pipe running parallel with the street,
belonging to the water company.
_Service Pipe._--Runs from the street main into the building.
_Corporation Cock._--Brass stop tapped into street main.
_Goose Neck._--Lead pipe which connects the street main and service
pipe.
_Trench._--Hole dug to receive pipe.
_Main Tapped._--Hole drilled through wall of main and a thread made
on it while pressure is on.
_Curb Cock._--Brass shut-off placed at curb.
_Solder Nipple._--Piece of brass pipe with thread on one end and
plain on the other end which connects lead and iron.
_Coupling._--Fitting which connects two pieces of pipe.
_Stop Cock._--Brass fitting for stopping flow of water.
_Curb Box._--Iron box extending from curb cock to surface.
_Curb Key._--A long key to fit in side of curb box to operate curb
cock.
_Swab._--Stick with ball of rags or paper on one end.