Need advise on changing main Sewer Trap.

[Kristian Antonacci]

Morning guys.
First of all wanted to thank the many DIY and plumbers that contribute to this forum. I always peeked in here time to time without being a member. I have learned tons and have found tremendous amount of help. Thanks!!!
Now on to my serious problem,,,,
I need to change out my main sewer trap. I know many of you will say to just remove it but from my understanding it is needed by code in NY.
I wanted to ask what the best route to attach a new cast iron trap to the existing pipe?
I thought about cutting it at the "A" point (shown in picture) and attaching on the new trap with a Fernco Coupling, but then im worried about it ending up too long and over shoot the vent (also shown in picture).
So I thought about removing the old trap properly to be able to slide in the new trap and seal it off with a Fernco coupling. Will this work?
Also I have no idea what size or type of Fernco coupling would work best. I looked on the Fernco website and they have ton of options that just confused me.
The OD circumference of the hub is 19 1/12 inches and the pipe itself is 14 1/4


I appreciate any help or suggestions you might have. Thanks in advanced

 

[Reach4]

I need to change out my main sewer trap. I know many of you will say to just remove it but from my understanding it is needed by code in NY.

Why do you think you need to change out your existing cast iron?

 

[Sponsor]

 

[Kristian Antonacci]

Why do you think you need to change out your existing cast iron?

It leaks from one of the joints and both inspection caps are broken.
I also want to go with pvc after the trap.

 

[Gary Swart]

This appears to be a pretty major job for a novice to undertake. It looks like there are several connections that have to be made very precisely. Not all plumbing jobs are DIY friendly, and when they are screwed up, can be very costly to repair.

 

[Kristian Antonacci]

Duplicate post

It's true I am novice. However I have a bit of experience with pvc and am a mechanic of motorcycle race bike which come in pretty handy as far as being precise. I also renovate my whole 2nd floor apt, plumbing included.
I realize this isn't easy but to be honest I have found myself doing a better job then the 2 contractors I've hired and then fired.
Don't mean to sound like an ass but just giving some background.

 

[Reach4]

You might chat with a local inspector to see what they suggest and allow. Searching around, I find the term "return bend" to describe a PVC piece that can be a component in your system.

Leaks can be fixed. A flat screwdriver can be used as a "caulking iron" to "caulk" the leaking lead joint.

Would you believe that a professional may use melted lead to join PVC to cast iron?

Cast iron is a premium sewer pipe material. Don't think of it as something you want to be rid of necessarily. Doing new stuff in PVC makes the most sense, of course.

 

[Kristian Antonacci]

It's true I am novice. However I have a bit of experience with pvc and am a mechanic of motorcycle race bike which come in pretty handy as far as being precise. I also renovate my whole 2nd floor apt, plumbing included.
I realize this isn't easy but to be honest I have found myself doing a better job then the 2 contractors I've hired and then fired.
Don't mean to sound like an ass but just giving some background.

I wanted to do everything in pvc but unfortunately they don't make the trap in pvc. I would have to make one but the "U" bend is going to be very deep and got concerned that the water won't be able to reach back up to flow out.

 

[Reach4]

I would have to make one but the "U" bend is going to be very deep and got concerned that the water won't be able to reach back up to flow out.

Don't worry about that part. The weight of the water into the bend will counteract the weight of the water leaving the bend. The problem with those is that they are a potential place for clogs to occur. So I guess you could be worried about sand and such not being able to flow out. That is what the cleanouts are for.

If you had that chat asking for local advice, consider doing that without an audience.

 

[Kristian Antonacci]

Anyways my local plumbing figured out what I needed. They sold me a new cast iron trap just like the one that's currently there and also 3 donuts to adapt to existing pipes.
So now I'm mostly concerned about removing the old trap and removing the existing lead.
Saw some videos that a torch will melt the lead so I might give that a try.
However I'm a bit worried it might not be a nicely sealed connection. Any tips or expoxies that might work to make a sealed connection from the hub>donut>new cast trap?

 

[Kristian Antonacci]

Don't worry about that part. The weight of the water into the bend will counteract the weight of the water leaving the bend. The problem with those is that they are a potential place for clogs to occur. So I guess you could be worried about sand and such not being able to flow out. That is what the cleanouts are for.

If you had that chat asking for local advice, consider doing that without an audience.

It's code in NY to have the trap.

Not sure what you mean on the audience part. If your talking about my local plumber I have to say he has help me out tremendously. However I felt like I holding up a line asking for this info while at the register. He explained but didn't really go into details, hence why I'm here.

 

[Kristian Antonacci]

This is my only option if doing it in pvc

 

[Sylvan]

NYC requires a double vent running trap and a FAI installed within 4 feet of the trap (1939 and 1968 code)

Fernco coupling NOT ALLOWED must be no hub couplings banded stainless steel, The clean out cannot be Jim caps and must be either CI Ferrule with a brass plug or a CI cap

Also in the photo it looks like the fresh air inlet is the same size as the trap 4"

By NY code the FAI shall be 1/2 the size of the building house drain but not less then 3" so you have play in replacing the trap and installing a new FAI tee

 

[Sylvan]

You might chat with a local inspector to see what they suggest and allow. Searching around, I find the term "return bend" to describe a PVC piece that can be a component in your system.

Leaks can be fixed. A flat screwdriver can be used as a "caulking iron" to "caulk" the leaking lead joint.

Would you believe that a professional may use melted lead to join PVC to cast iron?

Cast iron is a premium sewer pipe material. Don't think of it as something you want to be rid of necessarily. Doing new stuff in PVC makes the most sense, of course.

 

[Sylvan]

The " local inspector IF they give any advice will ask "are you a master plumber" and when I used to ask for some information the Manhattan inspectors would ask "do you have a code book or your supposed to know " and hang up

If the building already has cast iron I differently would not ruin the system by installing PVC

We are in doing 3 brand new 1 family houses and we were given the contract as we were the only plumbing contractors who refused to use plastic and after educating the architect we we given all three houses.

Some people do not mind plastic and hearing waste moving through the system or having a snake puncture a waste or soil line