On Mar 25, 10:45 pm, "Sacramento Dave" wrote:
"Speedy Jim" wrote in message

et...



wrote:

I've got a plumber (who I really trust) coming out tomorrow to
temporarily cut into one of my main cast iron waste stacks. Reason:
there is a crack in the foundation right behind the stack that is
going to be treated tomorrow with epoxy injection -- and the stack is
in the way.

Once the crack in the foundation has been treated, the plumber is
going to replace the cut-out section of cast iron pipe with PVC.

My worries: the waste stack runs all the way up to the 2nd floor (and
out the roof through the attic, so technically through to the 3rd
floor). Everything I read says you MUST support the stack when making
a cut like this.

I asked my plumber (very reputable company and he has done alot of
work in this house for me -- all of which has been good) if he would
need to support the pipe before making the cut. He said "no" -- but if
when he began to cut he though it needed it, he would support it from
below (in the basement, where he'll be cutting).

I am worried about this. It's a beautiful 1930s Tudor-revival era
brick & mortar home -- built like a tank -- and I don't want to have
all kinds of damage to the plumbing connections in the walls that
connect to this waste stack when it gets cut (I hesitated even doing
this, but the crack in the foundation is something that appears to
have needed attention for a long time -- it gets water, although I've
fixed most of that problem from the outside).

Help. What do I tell my plumber? Do I insist that he install a brace?
Does it need to be a permanent brace? I can't imagine how tying in PVC
w/neoprene gaskets is going to support the weight of this stack. How
does this work? Should I be worried -- or trust this guy (who has 40
years of experience in this area, working on these types of homes)?

Thanks for any guidance you can provide!

Be very worried. !!

It needs permanent bracing and the brace had better be strong
so that when the final cut is made, the stack doesn't drop
even 1/2".

There might a dozen connections into that stack, some of it
75 yr old galvanized pipe, some cast iron, some lead (closet bends).
A small shift will most certainly damage those joints but you may not
even see the leakage until this guy is long gone.

Jim

Riser clamp on the pipe. Without seeing the exact situation there more than
100 ways to support the clamp.

I'm not sure that can be done -- the pipe runs vertical up against the
poured foundation wall -- no studs on either side (it's not a finished
basement). Perhaps it needs to be supported from up in the attic?
These homes were built like tanks, so I'm assuming he thinks it is
supported on every level -- but I don't know that for sure...