I need to route a 3" PVC drain pipe from my garage (from the washer) to the
There is an interior wall separating the kictchen and garage. The washer is
sitting against this interior wall about six feet from the exterior block
wall. The kitchen sink is against the block wall on the other side about
another 4 feet from the interior wall. So from the washer to the kitchen
sink you have to route the drain along the interior wall, then make a turn
to connect to the kitchen drain.
My question is, should I do the routing from the inside or outside?
Inside: Run the drain from the washer inside the interior wall. When we
reach the exterior wall, make a 90 degree turn and go through the interior
wall. The other side is the kitchen cabinet. Drill through the kitchen
cabinet divider and reach the sink bottom, then open up the wall from the
inside, and connect to it.
Outside: Run the drain from the washer inside the interior wall. When we
reach the exterior wall, drill a hole in the concrete block wall so the pipe
can run through. Next locate where the kitchen drain is in that wall, knock
it open. Once you see where it is, break the exterior wall from the outside
and notch a trench that will take you from there to the kitchen drain.
Connect the pipes up inside the block wall, then cover it back up with
concrete, apply stucco and repaint the outside.
Which way is better? How do one drill a three inch diameter hole through a
conrete block wall? How easy is it to chisel out a trench along the wall to
seat a 3" pipe completely inside? I think that would be a lot of work? I
think routing the pipe completely out and back in will be real bad right?
Hold on there... A 3-inch drain just for a washer? Why so huge? Half
that size is typical.
Also, a block wall is only 6" thick. A 3" pipe buried inside would
require a 4" deep cut, at least, which would pretty much destroy the
integrity of the entire wall. And that wall could easily be load
I'd just route a 1-1/2" pipe using your "inside" idea. Your washer hose
might not fit in the pipe, in which case just add a 2" diameter stub on
the end, with a reducer fitting.
Why 3"? 1-1/2 or 2 (max) would be more typical for a washer.
My first question is about the relative heights...can you get enough
drop to go 6' to an elbow and then another 4' to the down stack?
There's going to be a problem perhaps in getting good flow. Also, what
about trap and the vent?
I never had to modify my washer drain pipe. I think it's galvanized steel,
I was flabbergasted once, years ago, to have a serious blockage. I had a
flood in my washing room because of it. It seems the detergent I was using
had caked the inside of the pipe, though I can't be sure. The problem
disappeared as mysteriously as it appeared. I had tried to flush the drain
with a hose, but that didn't work very well. What a mess that was.
I have long since changed to a different detergent. The problem never came
A washing machine pumps a LOT of waste water in a short time.
I'm not sure of your intended point, but yes, the pump discharge is
pretty fast, but it's nowhere near a 3" pipe full...
But, if OP doesn't have enough (or any) slope and vent, he's asking for
trouble even if he runs a 3" drain line...
Point taken. Sometimes it makes sense to build or plumb in excess of code
specifications. Case in point, using "L" copper where "M" is permissible.
I like the drain pipe exterior, if "permissible." Why wouldn't it be
It would be nice for your readers if you'd post a picture somewhere. Your
description is inadequate, yet overly wordy. Why don't you just say the
washer is in the kitchen? I see washers in garages, against interior walls.
"Inside the interior wall" could mean inside the garage..
If it is not in the garage, why don't you put it there? Who would want a
washing maching in his or her kitchen? Or is that a DISH washer?
My vote would be to put it in the garage, with piping exterior, as long as
code allows it. Aesthetics are of minimal concern in a garage.
Thank you for the reply.
I'm still not interested in deciphering those plumbing scenarios you
Why don' t you just get a professional to unblock the existing drain line,
if you can't do it yourself? In the garage, this should be easy. I had
unplug the washer drain pipe in my in-house washroom once, and that was a
mess. It flooded repeatedly.
I have already explored the suggestion you posted. To fix the crack in the
drain pipe that is currently located about 12 inches beyond the 8" thick
monolithic slab will require opening a hole on the kitchen side, ripping out
the kitchen cabinets for access, and ripping out tiles that has no
replacement. There is no access from the garage side because there is a
intermediate concrete footing that runs along the separation wall between
the kitchen and garage. Alternative 2 is to have someone dig a tunnel 6
feet long from the side under the house to fix it, either way the cost is
extremely high and has other side impact that may exceed the inconvenience
of the original problem. The soil is sandy. When the washer discharges the
water pull sand through the crack and pile sand downstream in the main line
which causes occasionally blockage. Right now my remedy is to pay $1000 a
year to clear that blockage by reverse jet sweeping.
Wow. When something is "cast in concrete," it is very hard to undo.
Conversely, I rationalize horrendous challenges and accomplishments to
"pride of ownership."
It's kind of like the devotion a person might show to a sick loved one. No
effort is too great.
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