wrote in message
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On Sun, 30 Nov 2008 23:54:08 -0500, "MiamiCuse"
wrote:

I cut opened a 4" wide trench about 8' long to pass a 1/2" PVC pipe from
the
wall to a kitchen island. Just as I was about to close off the trench my
wife asked if it's possible to have a sink in the island...

The island is about 7' from the wall, the trench is 8' long to that wall.
The nearest drain line that is open and accessible is the utility bath
room
which I do have the slab cut open and the 3" drain exposed.

I am contemplating running a 2" PVC drain from the island to the wall
(this
is not a problem as the trench is already cut and open), now once I am
there
at the wall, the utility bath drain is 7 feet away and the pipe has to
make
a turn to the right about 22 degrees.

So my challenges a

Can I really pass a 2" PVC pipe under 7' of slab? I don't want to cut the
slab open. It's mostly sand under the slab down here in Miami, If I do, I
have to do it from the utility bath end and hope that the pipe will appear
at the end of the trench where I can put in a 22" elbow. The problem I
see
is 7' is a long distance to bridge, and since I am starting from the
utility
bath end (downstream) it will be tricky to maintain the proper slope as I
get the pipe through.

Even if this all work, the run will be 8' + 7' = 15' to the tie in to the
main line and no venting. I could vent the pipe at the wall and run a 2"
vent up to the attic and tie in with another vent stack but even that is
not
to code as code calls for 5' maximum vent distance. Someone told me I
could
use a studovent? (spelling) how does that work? Does it apply in my
situation?

Thanks in advance,

MC



Across the state from you, same sand, I shot a 2" 22 feet under my
garage and hit a 1 foot square hole. Just be sure you have a good
trench with a straight shot to work from. You also need to get the
pitch right so you have to start deep and shoot up.
I made a drill head from a rounded 2" cap with a 5/16 hole in the
middle and three 3/16" holes around the edge 1/4 in from the edge.
Make up a 2" to "hose" adapter for the other end off of a 90 adapter
and about 2 feet of pipe as a lever.. Hook it up to the garden hose,
Turn the water on and start shooting while you twist the pipe back and
forth with the lever. It will go pretty fast and don't stop until you
are through or the sand will pack back in and stop you dead.
If you go fast you won't wash a big cavity under the slab.

BTW for our northern friends, I doubt this works in anything but sand.

The Studor vent is between you and the plumbing inspector. Some places
hate them, others are OK as long as you have a real vent on the stack
you are tying into.

How did you attach the garden hose? Did you do a 2" to 3/4" female adaptor
and connect the hose to that?

The problem I see is since the hole in my slab is about 40" wide, and I need
to span a 7' space under, I will not be able to put all 7' of pipe in the
right position (under slab and pitching up) to start with. I will have to
do 4' of it and then once all 4' are in, I will then have to take it all
apart, then glue a 2" coupler, then glue another 3' of pipe and reconnect
everything and continue again.