wrote in message
oups.com...
Again, "adding a few more feet of vent pipe" will do absolutely
nothing.

Sudsing at the base of a stack "is" a common problem - check this
newsgroup.

My 4" drain has perfect pitch, is not colapsed, etc. What happens is
that the soap/water hits the base of the stack (right where the tiolet
is.) There are enough suds (not a "little" as you claim) to
effectively stop proper venting.

I understand, we seem to be saying close to the same thing but using
different words. As I understand the physics of waste water plumbing, vents
are used so pressure or vacuum is not created in the pipes so that the water
flows freely to the sewer by the force of gravity.

The way your system is designed, there is pressure created when your washing
machine discharges sudsy water. This pressure does not have an escape route
via a vent so the pressure vents through your toilet trap. If a vent had
been installed at this point, the pressure of the sudsy water would have an
escape route via the vent pipe and not blow by your tiolet trap. This is
the few feet of vent pipe I was refering to.

Your suds are creating a temporary seal preventing the usual back flow of
air that is displaced by the water flowing through the pipe.




One way to fix this could possibly be to have the washing machine
discharge further down the line or move the tiolet further away
perpendicular from the main waste line or slow the discharge rate of
the washing machine.

The house was built in 1968 and was all done to code period.

Like I said before the code is a minimal standard, not the optimal standard.
The longer your sewage stays in your pipe, the more that sticks and creates
a build up.

I do not advocate ripping your house apart to install another vent just to
solve your problem with suds in your toilet bowl. I said before your
solution of changing soap might be the solution I chose to use. another
approach might be to use a reduced amount of soap. The softening action of
the Tide brand might be more effective in allowing the surfactants to
release the soil from your laundry.


I've
lived there for over 10 years and have never had a problem. I don't
think that Tide with fabric softner existed in 1968 and being that it
is the only type that causes this problem I don't necessarily fault the
plumbing.


Aint life grand? Just as the difference in life's experiences assist
justice and curb governmental abuses by having the jury system, so does the
internet facilitate the sharing of experiences and opinions.

Perhaps some folks installing a new waste system or working an existing one
might someday remember this thread and choose to buy a little bigger pipe or
perhaps attempt to save a few bucks and just try and live within the margins
of design they have set themselves.

In either case they will have a foundation for making an informed decision
or at least know what questions to ask.


--
Roger Shoaf
If you are not part of the solution, you are not dissolved in the solvent.