I am going to be replacing a small section of underground sewer pipe that runs from the front of my house toward the street. The existing underground sewer pipe is 4-inch cast iron. I will be using PVC to replace the line from the front of my house and connecting to that sewer line about 5 feet out.
Can I use a Fernco coupling to connect the new PVC to the old underground cast iron sewer pipe?
If not, how is that type of connection usually made?
That's how...
I would check with manufacturer and local codes on this . My neighbor used one as you said a few years ago and it ripped when they filled the trench. He didnt know until his toilet started backing up a couple of days later. Dont know if that is a problem with using coupling underground or an installation problem. I think they may have disturbed the ground under the new pipe too much.
Jimmie
ferncos are used here. in replacing the line its important to fill the trench with sand or gravel before placing line and get the slope right and the line properly supported along its entire length, and cover the new line the same as the bottom before backfilling espically if the line is extra deep, you dont want to drop big rocks on the new line.
kinda common sense things but lots of folks lack common sense:(
You could always put a larger diameter piece of solid plastic pipe around the Fernco to keep from damaging the Fernco. .
I kind of leaned more toward a screw up as the most likely cause too. I bet if the OP googles bury Fernco he will get all the info he needs.
Jimmie
OK I went ahead and goggled. Coupling should have a shear shield when buried . This is a stainless steel band that wraps around the coupling From the looks of things this come with the coupling and is not an add- on.
Jimmie
Thanks. I did try doing Google searches before posting, but I hadn't tried Googling for "bury Fernco". I too, did that after reading your first post, and that produced a lot of good information. I also saw some suggestions to use a shielded Fernco coupling.
I then went to
Thanks.
I installed two ferncos on a four inch ID concrete line about 10 years ago, and they are still holding up fine. The reason was to install a cleanout, as the existing one had been covered in concrete when the homeowner purchased the property.
I backfilled it with 3/4 minus, and then dirt making up to ground level. . No problems, and nothing has moved or shifted since installation.
Jon
There is one that is code approved for concealed locations and burial. I always have to ask at the supply house to be sure I get the right one. I think it is the one with the full metal sleeve but you better ask some one in your area just to be safe.
Colbyt
An MJ is better than a standard Fernco. It has a metal sleeve to protect it and give it some rigidity. Not sure of the size/adapter availability though.
Called an MJ (Mechanical Joint)
That's a really odd term as all flexible coupling joints are mechanical joints. The only term I've ever heard used for a shielded flexible coupling is shielded flexible coupling. ;)
look at
Fernco calls them "Proflex" oand "sheilded couplings" as well on their website. Another Ferco product is the "strongback", as well as the "no hub".
All of these are generically referred to by all the plumbing supply houses around here as "MJ"s, and that's how I was introduced to them by my old plumber friend ED the first time I ran into an application where one was needed. He just said "call Marks' and ask them for an MJ for sizeX PVC to size Y copper"
Problem solved.
What do local codes say about your use of PVC in sewer run that is presently cast iron ?
Would there be a problem obtaining cast iron piping and patching whatever pipe has given way ?
Since you are already digging up the pipe why not replace the entire run, as it gets expensive to dig it up and repair it 4' at a time...
~~ Evan
ferncos are used here. in replacing the line its important to fill the trench with sand or gravel before placing line and get the slope right and the line properly supported along its entire length, and cover the new line the same as the bottom before backfilling espically if the line is extra deep, you dont want to drop big rocks on the new line.
kinda common sense things but lots of folks lack common sense:(
++++++++++Thanks. I found this article which includes info on how to do the back filling after the new pipe goes in:
And on one of the Google searches I did, someone wrote something similar about surrounding the pipe with sand or clean dirt in areas that are rocky to prevent sharp rocks from damaging the pipe.
So, what you wrote is correct and worth noting even if it is common sense.
My point was that using a local term and pronouncing it as the defacto standard term on a nationwide, or larger, stage, is of dubious benefit. Doubly so as you are in Canada and the OP is in the US.
RIt would be much better to use a "no hub clamp". These have a stainless steel band in addition to the rubber and band clamps. They are much better about keeping the pipes in line and not allowing the pipe ends to misalign. These work quite well on cast iron to PVC connections.
MOST places PREFER PVC to C!.
when i had a similar situation, i drove about 10' of 3" INTO the 4" cast and that was the extent of my connection. MY connection was under a basement floor, so being out in the yard where little tree roots can (and will) go anywhere, you might want to pack such a connection with tar and wrap with some asphalt shingles or something to prevent the root infiltration.
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