plate into the basement determine where the
branch piping under the floor must be
extended.
Installing Cold Water Pipe
The following procedure for installing the
cold water pipe can also be used to install hot
water pipe.
1. Insert a length of 1⁄2″ water pipe through the
hole in the sole plate so it extends into the
space between the floor joists.
2. Temporarily install a 45° ell on the pipe as
shown, with a second length of pipe extend-
ing from the other socket of the 45° ell.
3. Raise or lower the assembly until the lower
pipe extends below the floor joist, far enough
beyond the drain pipe to allow the installation
of a horizontal water pipe parallel to the
drain pipe.
4. Mark the 45° angled pipe and make the nec-
essary allowance for the fitting before cutting
the pipe.
5. Temporarily install the 90° ell and a length of
1⁄2″ water pipe.
6. Temporarily fasten the 1⁄2″ pipe to the under-
side of the floor joists.
7. Mark and cut the length of pipe extending
above the sole plate to produce the required
rough-in height for the stub-out.
8. From the layout work described in Chapter 18,
the rough-in height for the kitchen sink water
supply stub-outs is 12″. This means that the
center of the tee must be 123⁄4″ above the
sub-floor (12″ + 3⁄4″ allowance for finished
flooring).
9. Hold the fitting in position and mark the pipe
below the fitting.
10. Add the fitting allowance and cut the pipe.
11. If air chambers are installed as shown, the
length of vertical pipe above the tee needs to
be at least 12″. The horizontal stub-out
should be long enough to extend 3″ through
the finished wall.
12. Two alternatives for riser fabrication are
shown in Figure 20-4: Option A—Water
Hammer Arrestor and Option B—Drop Ear
Ell. Once these components are trial fitted,
the joints can be made permanent from the
90° ell below the floor to the stub-out and
the pipe secured to the blocking near the
stub-out.
Before continuing with the installation of
the horizontal pipe under the floor joist, decide
how to run the water lines to the laundry area.
It is generally preferred that the horizontal pipe
runs under the floor joists or in the space
between two floor joists. Vertical drops from
the horizontal pipes are extended to the
desired height for the clothes washer and the
laundry tub, Figure 20-5. Given that the foun-
dation wall is left exposed in the finished
building, the pipe must be anchored either to
the concrete wall or to pieces of wood that are
anchored to the concrete wall. It is somewhat
easier to accurately locate the pipe if pieces of
wood are anchored to the wall before the pipe
is installed.
Installing Hot Water Pipe
Note how the hot water pipe is offset so it
can pass above the cold water pipe. Also, note
the location of the tees that produce the branch
to the kitchen. Since the horizontal hot water
pipe (A) will be above the cold water pipe (B), it
is easier to install the hot water pipe first. The
procedure is essentially the same as previously
described.
1. Begin by installing the hot water drop to the
stub-out for the laundry tub (C).
2. If air chambers are included, the tee for the
air chamber should be near the stub-out.The
air chamber should be at least 12″ tall and be
installed parallel to the foundation wall (90°
angle to the stub-out).
3. The outlet of the 90° ell, at the top of the
stub-out, should be at least 2″ above the
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Section 3 Plumbing System Design and Installation