The procedure in this article was a repair to an
old house that did not meet today's plumbing codes,
because the drain system was not vented properly. In fact,
the house shown here had NO VENT at all, which explains why
the drains always gurgled whenever the water was run.
The procedure shown here would not meet plumbing codes
in most places in the United States and Canada, where a
"P"-trap that connects to a vented vertical drain line would
normally be required. Water in an "S"-trap can easily be
siphoned out by lack of proper venting
We used an "S"-trap to rebuild the drain lines on this
bathtub because it was simple, it fit in the available
space, and we could reach it from the small access opening.
Before doing this project there was no trap at all.
Needless to say, the house is a piece of junk... literally a
textbook of code violations.
For exact code
requirements, we recommend consulting a licensed plumber or
your local plumbing inspector.
Drain Plumbing for information about adding a vent where
none existed before.