Outdoor Main Drains

Fixing Main Drain Plugged with Roots

Sometimes the main drain from the house may be
plugged with roots, or the drain to the septic tank might
be full; so first check to be sure other drains in the
house are clear. If other drains are plugged and toilets
don’t flush, the problem is most likely in the main sewer
outside the house. Temporary repairs can be made by using
a plumber’s tape, a 50′ to 100′ long strip of steel about
1″ wide and 1/8″ thick with a point on the end.

Find a cleanout plug in the basement near the
outside wall where the drain goes out to the septic tank
or street sewer. With a large wrench remove the brass
plug and start the point of the tape down the drain. If
the tape hits an obstacle, ram it back and forth until it
clear. When it clears you will probably hear the water
gurgle as the pipe empties. With a hose flush the
drainpipe before replacing the plug.

If the stoppage feels like roots, then if the water is
draining slow and the stoppage recurs frequently you
might try copper sulfate to kill the roots. The following
steps should be followed.

1. Where stoppage is serious and recurrent, apply 5%
copper sulfate crystals, once a month until condition is
much better. A drugstore or chemical supply store has
this material.

2. Follow this with one pound doses per year (mark on
your calendar).

3. Don’t allow copper sulfate to stand in fixture traps,
as metal corrosion may occur. Flush the crystals through
toilet bowl or through the cleanout in the basement and
follow with enough water to insure

(a) their transmission through the soil pipe to beyond
the cellar wall and

(b) their conveyance to and against the root obstruction.

NOTE: The clean-out is not the drain where you dump
laundry water. It is the place where a cap must be
removed to gain entrance to the drain.

4. Don’t expect immediate results from copper sulfate;
only the life of the roots is taken by the copper
treatment, and thereafter the normal processes of decay
must ensue before roots can be carried on out to the main

5. Don’t expect the treatment to clean sewers
mechanically obstructed by breakage, bad construction or
foreign material.

When copper sulfate is used in connection with a
septic tank tile field, the solution could be poured
into an opening in the tile line beyond the tank itself.
If you run the solution in through the septic tank
it will be diluted and not clear a stoppage in the tile
field and might temporarily affect the bacterial action
in the tank.