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Replacing corroded section of cast iron pipe and whole house trap with wye

pulper_11's picture

I have a question that I'm hoping to get some help with regarding replacing a corroded section of my cast iron sewer line (approximately 1 foot just behind the trap) and also replacing the whole house trap with a wye and cleanout. I’ve checked with my local plumbing inspector and it fine to do the trap replacement. 

I’ve done a lot of the digging myself and have gotten close to the part where the pipes will be replaced. I did the digging in order to save some $ but now that I am close to replacing the pipes I’m getting a little nervous that I could screw this up since I haven’t done this before and I will not have use of my facilities until it is done and if something goes wrong, that could be a while. I’ve contacted two plumbers in our area and they have given me a estimate of $2500 to $3000 for this work, including permit (permit will be $120). I’ve done this over email and sent them the pictures that are attached here. 

My question here is if the cost of this is in the thousands of dollars b/c of the difficulty of replacing the pipes accurately, the backfilling, or the cement work (or all 3)? It does seem high to me and I had heard that digging the hole was a large portion of the job. If you have any advice or questions, please feel free. I’m new to this and open to suggestions. Thank you!

 

What's the size of the (post #215062, reply #1 of 12)

What's the size of the pipe?  Is it butt up against the foundation?  What is beyond that wall?

How were you planning to cut the pipe?

Oh, and why do you want to replace it?  Do you feel about to corrode through?  How old is the house?


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Hi Dan: I believe it is 4" (post #215062, reply #2 of 12)

Hi Dan:

I believe it is 4" pipe and it is close to the foundation (about 6-8 inches away).  The wall is the exterior wall.  

I will certainly take suggestions regarding cutting the pipe.  I've read that an angle grinder is the way to go, but I've never done this before so open to any suggestions.  

The house is about 65 years old.  I had the line snaked about a month ago due to overflow in my floor drain.  They then used a camera and determined that the cause of the blockage was corrosion in the pipe just behind the trap.  

Do the pipes go under the (post #215062, reply #3 of 12)

Do the pipes go under the fondation out into the yard? If so the plumbers are bidding on the unknown and the problem of getting the new pipe under or through the foundation than patching the concrete back in. The actual pipe replacement is pretty straight forward and easy. 3 Fernco sleeves, the pipe and a wye will probably cost just over $100.00 and maybe 2 hours of time. It's getting to that point that can be a problem.

Florida Licensed Building Contractor, 50 years experience in commercial remodeling, new homes, home remodeling and repairs and all types building maintenance.

Thanks for your reply.  The (post #215062, reply #4 of 12)

Thanks for your reply.  The pipes do go under the foundation into the yard.  However, the area of corrosion is in the pipe going into the house, and is right next to the trap.  

To replace the trap with a straight pipe and a wye/cleanout, I would have thought (correct me if worng) that you could cut the current pipe at these two locations:

cut 1) on the sewer line in the house -  just beyond where there is the serious corrosion build-up

cut 2) on the sewer line heading outside to the main - just beyond the coupling to the trap.

Then the trap and the corroded part of the sewer line will be able to be removed.

Hopefully my description makes sense.  Obviously like you said the unknown here, based on pictures and my non-expert description, can cause uncertainty in an estimate.  

One additional question - I've read that Fernco sleeves are not code if placed under ground.  Mission couplers are required.  Is this correct?

Thanks for your assistance!

Consider that the tee or (post #215062, reply #5 of 12)

Consider that the tee or whatever below those two fittings extends out from the width of the fittings at least six inches.  This means that the connection between the tee and the drain beyond it is under the wall and possibly inside the foundation.

If nothing else you need to excavate more completely, until you have exposed the entire pipe assembly, out to a point beyond where the fittings join.  And you'll need to excavate under the pipes for a few inches as well.  Likely your hole will have to get larger.

Finally, consider where the drain camera found the corrosion problem.  Which side is "just behind" on?  (And are you confident that the pipe on the far side is sound?)


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Thanks Dan and Florida.  It (post #215062, reply #7 of 12)

Thanks Dan and Florida.  It turns out that the trap was too close to the foundation to replace it (good call Dan!).  I did have plumbers come in and do the plumbing for me.  It past the inspection of the work and I was able to watch them do it and learn things that I didn't know before (which is a lot!).  

I've now done the backfilling and am ready to do the cement work myself.  I've attached a pic of how it was before adding another bag of sand (i had to do a lot more digging and excavation since my last post b/c more pipes had to be replaced).  

I have a question regarding the cement work.  I figure based on volume that I would need about 6 bags of 60lb cement.  I figure I can mix 2 bags at a time in my wheelbarrow.  Once i get the first two bags to the right consistency and then dump them in and smooth a little, how much time do I have in order to mix the 2nd batch and dump that in?  I'll be using regular (not fast curing) sand cement.  I'm just concerned that I won't have enough time between batches to mix another batch.

Any advice is appreciated.  Thank you.

Here is the pic.   (post #215062, reply #8 of 12)

Here is the pic.  

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progress_june_25_20176.jpg
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Sand mix is not what you (post #215062, reply #9 of 12)

Sand mix is not what you want. You need concrete to do a structural repair. Mix, dump, screed and mix again until you have the hole filled then do a final screed and trowel.

Florida Licensed Building Contractor, 50 years experience in commercial remodeling, new homes, home remodeling and repairs and all types building maintenance.

it's not sand mix.  it's (post #215062, reply #10 of 12)

it's not sand mix.  it's sand concrete that i'd be using.  i was told that is easier to work with.  my main question here is how quickly do i have to mix the batches in between filling the holes.  thanks.  

Lol! Pour them as fast as you (post #215062, reply #11 of 12)

Lol! Pour them as fast as you like. But, if what you're using has "Sand" in the name it's not concrete.

Florida Licensed Building Contractor, 50 years experience in commercial remodeling, new homes, home remodeling and repairs and all types building maintenance.

shows how much i know! (post #215062, reply #12 of 12)

shows how much i know!  thanks for your help.

If you've already done most (post #215062, reply #6 of 12)

If you've already done most of the digging why not finish the job yourself? The plumbing work is all mechanical and all well within the abilities of a good do-it-yourselfer. I doubt that getting the old pipe out of the foundation will be easy as you think it can be done with elbow grease and imagination and possibly some magic words.

Florida Licensed Building Contractor, 50 years experience in commercial remodeling, new homes, home remodeling and repairs and all types building maintenance.