Cast iron shouldn't be problamatic (as DanG says), nor should copper, ABS or
PVC, but galvanized steel might, due to corrosion, causing clogging. Lack
of proper pitch is another possibility. The fact it keeps reclogging inplies
something's wrong or that it's not being fully cleared. You should be able
to estimate th edisitance to the problem by how much snake is req'd to reach
the obstruction. If this corresponds the the older section you may have
found the culprit.


"DanG" wrote in message
news:bihte.1860$Lr4.1048@fed1read03...

I seriously doubt that the cast iron lines have anything to do with your
problem unless they are not set to adequate flow grade. Cast iron can grow
nodules on the inside of the pipe that snag scum and solids, but I have
never seen any grown shut to the point of slowing water.

I suspect your problem lies elsewhere. If the original piping is fairly
easy and it would make you feel better, go ahead and replace it. I just
don't think it will be the end of your troubles.

(top posted for your convenience)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Keep the whole world singing . . . .
DanG (remove the sevens)




wrote in message
ups.com...
Hi,

I recently posted about water backing into our tub on the first floor
where the tub, kitchen sink and dishwasher all share a common drain.
After having a plumber out to snake it it started happening again today
so I snaked it myself and this time I was able to unclog it myself. I
learned a couple of tricks watching that plumber!

But the big problem is that it keeps reclogging so we must only be
opening a small passage each time we snake it. A guy I know looked at
our plumbing downstairs and pointed to a section that is older pipes
and said if I replace this one section it will cure the problems. He
thinks the insides of that pipe have mineral scale built up and that we
are only clearing a small hole each time we snake it. There is a lot
of plastic pvc that was installed when we had our kitchen and bath
renovated but there is this one section that is the old stuff.

What do the plumbing experts here think about this?

Thanks,
Steve