Drain into Cleanout Fitting

[Bob Foley]

I've seen yes's and no's so I 'm looking for more opinions. I am planning a small powder room install, adding a sink and toilet into a modified - enlarged bedroom closet. I've got enough room by any standards I have seen and the location is perfect to tie into the waste pipe heading out of the full basement-right underneath in the ranch house. Here's my question. The existing bath, kitchen, washer all tie in pretty much under where my proposed powder room will be located and it seems like a simple tie in would be into the existing cleanout plug on the end of the 4" Cast iron soil pipe that heads out of the house. I would add a new cleanout after I attach a sweep or wye (that have provisions for a cleanout) onto the pipe. Is there any issue tieing into the where the clean out is located given I will add a new cleanout? The existing threaded cleanout is fitted into the existing CI that has a hub and its a lead/oakum old installation. I see two ways to tie into this: (1) My preference, is to install a 4" to 3" hex reducer into the threaded cleanout threads. Seems simple enough to then add a male PVC adapter and I'm off an running from there. I've got couple of comments that you can not use threaded fittings on waste lines per codes. Aside from code issues, especially with a very accessible 3" pipe cleanout 6" away, I can't see how that would ever be a problem. (2) Approach 2 would be to take out the leaded threaded fitting that holds the cleanout plug and install a rubber donut with 3" PVC then off to the new piping. Couple thoughts here. I believe there are donuts available for hub cast iron pipes and if I don't have to, I'd rather not have to take out the lead etc. and clean up the hub. The 'good' part of that approach is that the fitting is chest high, nothing near it so easy to work on. What's the plusses and minuses? Or is there a better way? Given the tub, sink, toilet, kitchen, washer, drains and vents in a small area right at the soil pipe out of the basement ( all 2" and 3" copper) there really isn't much room to tie into any of the existing piping. Thanks

 

[Sylvan]

Who said you can't use threaded piping or fittings on waste or soil lines

I used 4" - 6" threaded galvanized piping on waste, soil and storm lines because the engineer did not trust bell and spigot cast iron to hold pressures exceeding 60 PSI

They make threaded galvanized "drainage" fittings for a very valid reason

 

[Sponsor]

 

[hj]

Your second problem, after you cannot connect to the cleanout, unless you install a new one, is that the cleanout is probably 3 1/2" pipe thread and there is NOTHING that will connect to it.

 

[Bob Foley]

The threaded brass cleanout plug measures 4" across. Is that not a 4" fitting? It is installed into a cast iron pipe that has a hub on the end where there is the female thread leaded into the hub. My intention for a new cleanout is to use a wye type or long sweep fitting that has a straight run such that on the end I could install a new cleanout. I got an idea sketch somewhere. I'll see if I can attach.

Assuming the thread proposal won't work, is the next choice to dig out the lead-oakum fitting and use some sort of donut into the cast iron ?

hub?

 

[seann]

If I was you I would avoid the donut gasket route. If you are not an experienced plumber I do not think you would be able to get your get your PVC pipe to fit into the donut gasket after installing it into the cast iron hub. It is a very very tight fit! It's not as simple as it seems. I don't know how much room you have on the vertical stack between the wye for your clean out and the 3"double wye going to the toilet and bathroom group? If there is enough room? The easiest thing to do would be to get a sawzall and cut out a section of the 3" cast iron on the vertical stack area between the double wye and cleanout wye. You can just use regular bi-metal sawzall blades, you don't need the exspensive diamond blades to cut through the cast iron. You will use 1- 1.5 blades per cut, so grab 4 blades just to be safe. Then install your 3x2 wye there by using 2 no hub bands that are CI x PL. To go from cast iron to plastic(PVC) . You could use 3"fernco couplings also if they are legal for use above ground in your area. Fernco couplings will work fine but in my town they cannot be use above ground. Just the code in my area. Next city over from me they are legal. The no hub bands offer more support though in my opinion. If there is no room to cut in a 3x2 in the stack then your first idea seems logical. Just seems like more work and lesser quality outcome.

 

[hj]

If the plug is 4" across, then it IS a 3 1/2" thread and the only thing that would fit it is another plug, period.

 

[Bob Foley]

If the plug is 4" across, then it IS a 3 1/2" thread and the only thing that would fit it is another plug, period.

There are a number of manufacturers who make 3 1/2" x 3" pipe thread hex bushings, both malleable iron and galvanized.

 

[Bob Foley]

I found several 3 1/2 inch bushing manufacturers