On Fri, 26 Jun 2009 18:54:28 -0700 (PDT), "hr(bob) "
wrote:

On Jun 25, 10:17*pm, mm wrote:
On Thu, 25 Jun 2009 22:46:55 -0400, "Ed Pawlowski"
wrote:
"mm" wrote in message
.. .
Is home sewer pipe relining a good idea? *As opposed to trenching and
laying in a new sewer pipe.

Does it really last 50 years like the plumbing companies that do this
claim?

The drain is supposed to have a leak and fill with water at a low
spot, and that's why the basement toilet will back up if the other two
toilets are flushed in quick succession, or if the washing machine
drains.

If there is a low spot, chances are water would just lay in there anyway.
I'm not so sure how a liner is going to solve that problem, but a new line
could.

So any low spot is bad. *I suppose a leak in terra cotta pipe could
let water in or water out, and the water coming out could make the
ground settle more around the leak, if there were some place for it to
settle to, but could it wash enough away for the line to sag? *

This had been a well line which worked fine until a week ago. *So
presumably it had no low spots then.

The line was roto-rooted a couple days ago, and then again with bigger
blades, all the way out to the city sewer. *I keep thinking a clogged
vent pipe might be a lot of the reason the toilet backs up.

How could a clogged vent pipe cause back-ups. They are there to

I don't know. I thought I read it here. That it was something that
was often overlooked that could cause backup problems, or at least
slow flushing.

Maybe because it can be hard for the air to exit the drain pipe
quickly enough to make room for the water. By having a functioning
air vent, there is a second way for the air to exit, in addition to
the drain pipe itself.

prevent siphoning water out of traps for other fixtures on the same
line when someone flushes a toilet .

Things invented for one function often serve other functions, right?
Maybe since the use of air vents, they've been able to make drain
pipes smaller, and now the air vent is essential to toilet draining.

I don't know and I don't remember exactly what I read here, but it's
not impossible.