Thank ya kindly for reading....

I have an older house with an old cast iron 4" sewer drain pipe running along the basement out to the public sewage system.

A section about 6" long rusted out and the bottom collapsed. This was discovered after the kid went to the bathroom. FUN!!!

So I went back a few inches on each side, cut out the rusted section.

I got a PVC pipe replacement and cut it to fit.
I used 4" black rubber couplers as directed by books and the label itself.

Clamped it all together and Viola!

Not quite....I have a slow drip on each end. The cast iron is smaller than the pvc so it isn't as tight. Is it typical to seal the cast iron portion with a sealent of some sort or should I try to find a rubber coupler that is 4" on one side and 3.75" on the other.

I'd be at Home depot now exploring my options but I have the kids and my wife is not home yet.

Any advice while I wait?

 

Are you sure the adapter you bought was for cast to PVC?

 

yep....designed for it according to the label.

 

What would be better than the "Fernco" coupling that you are using is to use a proper transitional coupling. The brand that we use is " Mission". It's a neoprene coupling (similar to the Fernco) and uses a stainless steel band for tightening. It's a much better transitional fitting. I believe that the HD has this type, but don't offer a wide range of sizes.

There are a couple differend "sizes" of CI pipe. There is service weight, marked SV on the hub, and there is extra heavy, marked XH on the hub. These have different outside diameters. In the Mission brand I use a CP44 to connect 4" SV CI to 4" PLastic pipe. 4" XH CI to 4" PL would be a P400. The HD is a great store but a plumbing supply would have the parts to do the job right. Once.

You might also want to consider cutting the CI pipe further from where it rotted through. There is a good chance that there are others spots that are about to give way soon.

We see this often around here. There are a lot of older homes with the CI drainage piping. It can be a complicated fix because it's sometimes necessary to replace fittings that accept waste from branch drains. I hope that your situation isn't like that.

Good luck!

 

great info thanks...

I'm definitely dealing with different diameters.

I will check that out when I go back over.

Luckily I don't have to deal with the branch lines, etc.

I did cut back about an 1" or 2 past what looked solid to me to be sure.

Thanks again.

 

This sounds like an awful crappy subject!













Sorry, someone had to do it.