I am about to do a modest bathroom remodel on a 40 year old house. The existing DWV piping is black plastic ABS pipe. I want to use the white PVC but I read somewhere that you should not join the two different pipe types directly. Is this accurate? If so, what is the easiest method. The only other couplings I have seen in the Home Depot are those rubber fittings with metal clamps.


Thanks in advance

Comingling ABS and PVC became much more permeate with Oatey All Purpose Cement. All you need is Primer, Oatey Cement and a coupling of either ABS or PVC. Good luck, Tom

In 2001, we purchased a manufactured home which has the sewer abs black. Our septic was PVC white. We paid over $300 and had a inspection which passed. They installed a rubber coupling. All fine and dandy until a week ago Feb 2010 we smelled something funny and discovered the black ABS pipe fell out of the rubber coupling and sewage all under our house! I read where if I ever went to sell it that sometimes it has to pass inspection. I studied it and this is what I ended up doing LOL
I took that rubber coupling crap and threw it away. I drained all the sewage. I purchased a white male end screw in type fitting and glued it to the septic/white pvc side using proper glue. I then got a female black ABS end and screwed it into the white side! There you go and if that doesn't pass who cares because I will not clean up sewage again. Now I have to purchase some lime to clean up the smell .


My recommendations is join them using a male end black/white and a female end black/white. If that does not work they do make a glue green that is compatible glueing the two abs and PVC together. I chose the male/female screw into each other method.

Mountain,
You are responding to a 4 year old thread that's dead. Please look in the upper left hand corner for the date. Thanks, Tom

I am sorry speedball1. When one pays $300 and passed inspection then finds a huge puddle of sewage under there house well lets just say I did not even notice the date of this thread until you mentioned LOL

Moiuntain, Fernco couplings are designed to connect PVC and ABS pipes. If your coupling slipped it was because it wasn't properly installed, tighted with tension pre-set wrench and tested when originally installed. Also, each end of the pipe has to be inserted into the coupling all the way with only 1/8" separation between those two.

Such a connection with Fernco coupling becomes weak point in the pipe. To prevent pipe separation pipes have to be properly supported. If installed properly - it will last as long as rest of the plumbing in your house.

Thank you Milo Dolezal. The installation which was installed in 2001 was not tested. The Fernco coupling rubber was still in very good shape. The problem was the top band was not tightened to proper tension and the installer only put two inches of black pipe in the Fernco coupling. With only two inches placed into the Fernco Coupling and the band not tightened to proper specs is the reason it failed. The rubber of the Fernco coupling was in very good shape. Like the day they purchased it. I couldn't believe it passed inspection!

Quote:

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Originally Posted by Milo Dolezal

Moiuntain, Fernco couplings are designed to connect PVC and ABS pipes. If your coupling slipped it was because it wasn't properly installed, tighted with tension pre-set wrench and tested when originally installed. Also, each end of the pipe has to be inserted into the coupling all the way with only 1/8" separation between those two.

Such a connection with Fernco coupling becomes weak point in the pipe. To prevent pipe separation pipes have to be properly supported. If installed properly - it will last as long as rest of the plumbing in your house.

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Exactly Milo it was operator error. Top band not tightened and only two inches of black ABS pipe inside the Fernco coupling. I estimaged approx black ABS pipe was 4 inches away from the PVC pipe.