# Increasing storm drain size at begining of run



## NyNick (Feb 14, 2013)

Im in NY under IPC. I need to replace 10ft of 4" cast iron storm drain. The 4" is the first drain on the line. It connects to 8" Boston with cleanout. Can i swap the 8" combination fitting out for a 4" combo with cleanout and tie it into the 8" main using 4 x 8 reducer/increaser or transition coupling?

Thanks
Nick


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## skoronesa (Oct 27, 2015)

NyNick said:


> Im in NY under IPC. I need to replace 10ft of 4" cast iron storm drain. The 4" is the first drain on the line. It connects to 8" Boston with cleanout. Can i swap the 8" combination fitting out for a 4" combo with cleanout and tie it into the 8" main using 4 x 8 reducer/increaser or transition coupling?
> 
> Thanks
> Nick


So you'd no longer have an 8" cleanout, and instead would only have a 4" cleanout on an 8" line? Doesn't sound legal to me. Pretty sure all cleanouts must be full size.


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## skoronesa (Oct 27, 2015)

Nevermind, I was wrong, 4" would be legal.


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## NyNick (Feb 14, 2013)

skoronesa said:


> Nevermind, I was wrong, 4" would be legal.
> 
> 
> View attachment 130381


Yup. Orrrr wouldnt it..... ? I know what the code says. I also know I havent seen what I proposed done. It looks stupid and feels illegal so I thought id ask. Having established that....you think that setup would fly?


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## skoronesa (Oct 27, 2015)

NyNick said:


> Yup. Orrrr wouldnt it..... ? I know what the code says. I also know I havent seen what I proposed done. It looks stupid and feels illegal so I thought id ask. Having established that....you think that setup would fly?


Unless you cant get the fitting, why not keep it as a 8x4 wye and have a full size cleanout. Id be pissed if I went to jet it and only had a 4" hole to pull back 8" of crap.


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## Sstratton6175 (Jan 10, 2021)

There is absolutely nothing wrong with a 4” clean out on an 8” line. We do this all the time and have never failed an inspection for it. We’d typically install an 8x4 wye fitting with a 4” eco every 100’ or at every change of direction greater than 45°


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## NyNick (Feb 14, 2013)

skoronesa said:


> Unless you cant get the fitting, why not keep it as a 8x4 wye and have a full size cleanout. Id be pissed if I went to jet it and only had a 4" hole to pull back 8" of crap.


50 year old piping. Cost. Time. Curiosity. The wye is brittle. And not supported its sagging a little. Its buried above a drop cieling in an office of a hospital. It has a previous crack that the house plumbers repaired with a bowl wax ring. They stuffed crack with wax to stop the leak. Not joking. it works except during really hard rain and now whole length is cracked with this new one. And the pipe it has to be repitched and hangers added. The 4" would be easier to work with. Im trying to not touch 8" at all. Thanks for your reply though I was hoping to get more replies, advice, hate mail on this. Should I transfer it to the Code forum?


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## NyNick (Feb 14, 2013)

skoronesa said:


> Unless you cant get the fitting, why not keep it as a 8x4 wye and have a full size cleanout. Id be pissed if I went to jet it and only had a 4" hole to pull back 8" of crap.


50 year old piping. Cost. Time. Curiosity. The wye is brittle. And not supported its sagging a little. Its buried above a drop ciean office An


Sstratton6175 said:


> There is absolutely nothing wrong with a 4” clean out on an 8” line. We do this all the time and have never failed an inspection for it. We’d typically install an 8x4 wye fitting with a 4” eco every 100’ or at every change of direction greater than 45°


So just to be clear I talking about changing out a combo 8×4 wye w/ 8th bend and putting in its place a full 4" combo wye w/ 8thbend. This will pick up the first drain on 8" horizontal storm drain. Soil ill have a 4" fitting at the start of the line immed increasing to 8"


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## skoronesa (Oct 27, 2015)

NyNick said:


> 50 year old piping. Cost. Time. Curiosity. The wye is brittle. And not supported its sagging a little. Its buried above a drop cieling in an office of a hospital. It has a previous crack that the house plumbers repaired with a bowl wax ring. They stuffed crack with wax to stop the leak. Not joking. it works except during really hard rain and now whole length is cracked with this new one. And the pipe it has to be repitched and hangers added. The 4" would be easier to work with. Im trying to not touch 8" at all. Thanks for your reply though I was hoping to get more replies, advice, hate mail on this. Should I transfer it to the Code forum?


I was under the impression this was outside, in a trench. Clearly no one is going to be jetting in a drop ceiling so do whatever is easiest.


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## NyNick (Feb 14, 2013)

skoronesa said:


> I was under the impression this was outside, in a trench. Clearly no one is going to be jetting in a drop ceiling so do whatever is easiest.


Yeah its not even inspected..I never did this. But it seems like it can be done code wise. Unless...the 4" run on the the 8" main is seen somehow as a reduction of size in the direction of flow.


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## gilbertjeffrey (Mar 6, 2011)

Don’t know your code but pretty sure in my code UPC you only need full size clean out up to 4”. And it’s common to have 4” clean out going into a 6” line. Actually all the sewer tie ins are like that here. They run 6” clay to the property line and reduce to 4” with a clean out on the riser.


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## Sstratton6175 (Jan 10, 2021)

The only potential issue I see with this is the possibility that the 4” roof drain was replace at some point and used to be larger, and now is under sized. If you’ve calculated the roof area served by the 4” drain and its within the capacity I see no issues here. I will agree with you that the transition from 4” to 8” looks odd, but only because the 8” is grossly oversized not because the 4” is too small.


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## sparky (Jan 8, 2014)

skoronesa said:


> So you'd no longer have an 8" cleanout, and instead would only have a 4" cleanout on an 8" line? Doesn't sound legal to me. Pretty sure all cleanouts must be full size.


In ky we have to have full size cleanouts in pipe up to 4" in size,after 4" cleanout scan be a minumum of 4" so IMO he would be ok with the 4" cleanout unless he has to plug the line off with a blowup,then4" is a Nono


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## sparky (Jan 8, 2014)

Sstratton6175 said:


> There is absolutely nothing wrong with a 4” clean out on an 8” line. We do this all the time and have never failed an inspection for it. We’d typically install an 8x4 wye fitting with a 4” eco every 100’ or at every change of direction greater than 45°


Correct


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## NyNick (Feb 14, 2013)

sparky said:


> In ky we have to have full size cleanouts in pipe up to 4" in size,after 4" cleanout scan be a minumum of 4" so IMO he would be ok with the 4" cleanout unless he has to plug the line off with a blowup,then4" is a Nono


Its not just the 4" cleanout. Theres no question about that. The question is 4" on the run. Sticking a full 4" on an 8" main.


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## sparky (Jan 8, 2014)

NyNick said:


> Its not just the 4" cleanout. Theres no question about that. The question is 4" on the run. Sticking a full 4" on an 8" main.


That's usually the way it's done,you go from little to big,not reverse,think of a periscope


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## Sstratton6175 (Jan 10, 2021)

NyNick said:


> Its not just the 4" cleanout. Theres no question about that. The question is 4" on the run. Sticking a full 4" on an 8" main.


If that section of the drain is only carrying the one 4” drain than it only has to be 4” pipe!!


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## skoronesa (Oct 27, 2015)

NyNick said:


> Its not just the 4" cleanout. Theres no question about that. The question is 4" on the run. Sticking a full 4" on an 8" main.


I think you need to draw us two pictures, how it is now, and how you propose the new pipe to be.

Y'all are talking in circles right past each other!


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## karlwithak.conley (Nov 26, 2021)

I read all the previous posts. I understand that this is an 8” horizontal storm water line serving nothing but roof drains. (I am assuming this is not some sort of combination sanitary and storm combination system.)
Another poster quoted a code section that allows the 4” cleanout. Since the line will never see solids bigger than some leaves or feathers the 4” cleanout makes perfect sense. All the water entering is coming through a roof drain strainer. Just because it looks funny doesn’t mean it violates codes. I never felt like heel inlet ells and side inlet tees felt “right” but they really work great in some applications. Same way for “Sovent” system fittings. They look entirely wrong, but are allowed by many codes and have over 50 years in service proving the concept.


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