Hello. I'm installing a toilet/lav/shower in my basement. My question is... Can I sit the toilet flange directly on top of a 4" 90 degree closet bend PVC fitting? This fitting has only one hub, which will connect to a 4" PVC at 1/4" per foot over 3.5 feet and tie into a cast iron tee fitting on the existing vertical soil pipe. I hoped to run a vertical pipe 6" out of the 90 degree PVC fitting to tie into the toilet flange, however, I do not have the clearance.

I thank you in advance for your help.

Hello. I'm installing a toilet/lav/shower in my basement. My question is...Can I sit the toilet flange directly on top of a 4" 90 degree closet bend PVC fitting? This fitting has only one hub, which will connect to a 4" PVC at 1/4" per foot over 3.5 feet and tie into a cast iron tee fitting on the existing vertical soil pipe. I hoped to run a vertical pipe 6" out of the 90 degree PVC fitting to tie into the toilet flange, however, I do not have the clearance.

I thank you in advance for your help.
... as the name implies is suited for this purpose. I wish I could have found one of these when I went shopping for one but instead got handed an ordinary 1/4 bend. Why not cut the 6" pipe to length if as you say you don't have enough clearance? BTW... the cast iron tee fitting should be a sanitary tee if you have other drains connecting upstream from this connection point.

If I were to cut the 6" pipe to length, I would have to cut it at the top of the 1/4 bend. Instead, I plan to cement a closet flange directly to the top of the 1/4 closet bend. After talking to a local plumber and reading your reply, this is commonly done. I did not realize this and I thank you both.

Here is my new problem. I connected the cast iron (sanitary) tee the the existing 4" cast iron vertical soil pipe with Fernco Proflex Couplings (Neoprene rubber w/ stainless steel clamps). I cannot get a tight seal. Water drips from the coupling when the upstairs facilities are used. I tried tightening the clamps, but I can't stop the leak.

Are there any tricks to using or installing these couplings? Has anyone had any experience with another brand? Thanks for any help.

If I were to cut the 6" pipe to length, I would have to cut it at the top of the 1/4 bend. Instead, I plan to cement a closet flange directly to the top of the 1/4 closet bend. After talking to a local plumber and reading your reply, this is commonly done. I did not realize this and I thank you both.

Here is my new problem. I connected the cast iron (sanitary) tee the the existing 4" cast iron vertical soil pipe with Fernco Proflex Couplings (Neoprene rubber w/ stainless steel clamps). I cannot get a tight seal. Water drips from the coupling when the upstairs facilities are used. I tried tightening the clamps, but I can't stop the leak.

Are there any tricks to using or installing these couplings? Has anyone had any experience with another brand? Thanks for any help.
... posts/replies by Speedball1 I think you will find the best way to join cast to cast is with solder and what have you (not an expert with cast). Find one or more of these and you will see it is quite simple to do if you follow Tom's (Speedball1's) recommendations.

If I were to cut the 6" pipe to length, I would have to cut it at the top of the 1/4 bend. Instead, I plan to cement a closet flange directly to the top of the 1/4 closet bend. After talking to a local plumber and reading your reply, this is commonly done. I did not realize this and I thank you both.

Here is my new problem. I connected the cast iron (sanitary) tee the the existing 4" cast iron vertical soil pipe with Fernco Proflex Couplings (Neoprene rubber w/ stainless steel clamps). I cannot get a tight seal. Water drips from the coupling when the upstairs facilities are used. I tried tightening the clamps, but I can't stop the leak.

Are there any tricks to using or installing these couplings? Has anyone had any experience with another brand? Thanks for any help.



Cast Iron can be lumpy and have irregular walls so that the clamp won't make a watertight seal. Try this. Take some silicon gel and coat the pipe under the coupling clamps and then tighten the clamps. Good luck, Tom

Thanks Tom. I bought a different type of coupling... these ones have 4 clamps and seems to be holding so far.

I now have a question about venting. I understand that the toilet is self venting. My question is... for the shower and lav... if the 2" PVC drain lines discharge close enough to the existing 4" Cast Iron soil pipe (which vents through my roof), are they properly vented? Please see the attached picture.

I thank you for your help.

"I understand that the toilet is self venting."
Not exactly. In most applications the toilet is wetvented by the lavatory vent.
I hate to break this to you but your diagram tells me nothing. All I see is two 2" pipes connecting to a 4" pipe. I assume the lavatory is vented and 4 feet is within code. However you give me no information about the 7 foot run of 2". If both 2" pipes are arrempting to vent out the 4" stack vent then you are discharging a major fixture past two unvented minor ones and that's way out of code. Suggestion: Vent the lavatory out the roof, tie the other 2" into the lav drain and the entire group will be vented. Good luck, Tom