[Deck]

The plumbing code for my city says specifically: "Hubless cast-iron pipe shall not be permitted for inside leaders." I've googled inside leaders but I can't figure out what it is. The first hit on google is something called a rain leader, which may be inside or outside.

Some context on this, I'm trying to replace a rusting away piece of cast iron with a hubless cast iron which I'll connect with the right couplings. Also there is a vent pipe to the right of a double vented trap that vents out, and I'm thinking about replacing that. Is that a leader? A pic can be found in this thread.

Another thing I'm wondering is Home Depot sells cast iron 4" DWV pipe but it says "for underground use" but then goes on to say "for use in a dwv system". So does that mean I can use it above ground?

How should I hang the pipe? Cast iron is so heavy and all the hangers I saw at Home Depot seem so dainty. They sell strapping but it's a very thin gauge. You can actually see I already used it as a stop gap in the pic. Is there a certain thickness required?

 

[mikey48]

Why not use ABS? Much easier to install and will rust away.

 

[TheEplumber]

The plumbing code for my city says specifically: "Hubless cast-iron pipe shall not be permitted for inside leaders." I've googled inside leaders but I can't figure out what it is. The first hit on google is something called a rain leader, which may be inside or outside.

Some context on this, I'm trying to replace a rusting away piece of cast iron with a hubless cast iron which I'll connect with the right couplings. Also there is a vent pipe to the right of a double vented trap that vents out, and I'm thinking about replacing that. Is that a leader? A pic can be found in this thread.

Another thing I'm wondering is Home Depot sells cast iron 4" DWV pipe but it says "for underground use" but then goes on to say "for use in a dwv system". So does that mean I can use it above ground?

How should I hang the pipe? Cast iron is so heavy and all the hangers I saw at Home Depot seem so dainty. They sell strapping but it's a very thin gauge. You can actually see I already used it as a stop gap in the pic. Is there a certain thickness required?

This is a good example of local codes overriding the basic national codes.

My code (UPC) does not use the term 'leaders' unless addressing rain water or storm piping.
Also, you're local is restrictive on no-hub pipe. My experience is that it is approved above and below grade, interior and exterior- I have installed more than I care to remember..... I suggest you talk to your local code office for clarification.

For support- at every joint or within 18" each side of the joint. Vertically- at every floor.

I suppose there is a heavy strap method, but my cast iron work was mostly commercial- I used loop hangers or clevis hangers on the pipe. 1/2" allthread for 4" pipe, hung from the framing.

 

[Deck]

Why not use ABS? Much easier to install and will rust away.

My code also limits plastic piping to PVC and only above ground (no idea why). Typically around here at home centers PVC is far more accessible. My concern with PVC is that it would be loud. This piping is hanging in a basement room and above it is a bedroom. Do you think it would be possible in the bedroom to hear sounds from the PVC piping? I'm replacing less than 10 ft, including a bend. Right now with the cast iron I can't hear it from the bedroom. From the bedroom I hear it a little from the floor above go down the stack (also cast iron) but not below. If I go into the basement room I can hear it but it's not loud.

My code (UPC) does not use the term 'leaders' unless addressing rain water or storm piping.

Thanks for checking. I also found a definition in the NY state plumbing code definition section:

LEADER. An exterior drainage pipe for conveying storm water from roof or gutter drains to an approved means of disposal.

 

[Tom738]

Never expect what home depot says something is good for to be a permitted use under code. Especially not in Westchester, where some of the inspectors have reputations for being very peculiar and hard to work with. It's up to your local inspector what he wants to pass. You run a lot of tiny fiefdoms of bureaucracy and nonsensical rules rules and really stupid protectionism there. (It's a place where you can't hire a plumber to drive five minutes to the next town without having him have a separate bond, etc...) Not quite as stupid as NYC, but in NYC there are professional "expediters" who paper over some of the crazy with big wads of money.

Cast Iron is quieter. If it's only a short run there's no harm in using it for replacement, although obviously it's a lot more expensive and a bit harder to work with than plastic pipe.

I've only ever heard "leader" used to mean the pipe the gutter drains through.