I have a leak that has progressed into a problem in my living room's ceiling tiles. My shower is directly above and the drain p-trap is visible through the tiles. A couple of tiles have become soggy and discolored, so I removed 6 - 14" ceiling tiles to see the problem. The ceiling section above those tiles is water-logged and started to show holes from the water leak. My question is how would I go about replacing the section of cast iron drain pipe that is leaking? I have heard that I need to cut out the damaged pipe and replace with PVC pipe. Any comments or help would be much appreciated. Also any pictures of repair would be great help. I would like to do this repair myself since my home warranty company went belly up on me and took my $500.

thanks again, blake

ballengerb1

With the tiles removed can you see where the water is leaking. Does it leak only when the shower is in use and can you see up the side of the shower to where the mixing valve is mounted? We need to be 100% sure it is actually the drain pipe

massplumber2008

OK...pretty easy job all in all..especially if it is just a straight run of pipe. You will need the following:

I will assume you have a 2 inch cast iron pipe in place but if it is a 3 inch or even a 4 inch just order this list by the correct pipe size

2 - 2" - 4 band no hub clamps (not the fernco type at home depot..get real clamps at the plumbing supply house)
2 - 2" No hub x 2"PVC adapter
1 length of 2" PVC pipe
1 pt. PVC primer
1 pt. PVC cement
1 pkg. 6 inch sawzall blades (can be 8-10 teeth/inch, or they sell a graphite type sawzall blade just for cutting cast iron pipe).
2 - 2" PVC x 12" perforated strap hangers

Make sure pipe is secure and cut out the bad section of pipe with sawzall...Here, I cut about 7/8 the way through each cut before completing either cut. Then with help I finish cutting through each end of the pipe and drop the section out and to the floor.

Then you measure the distance of the pipe removed and deduct 1/2"...THIS is your overall measurement needed for the replacement pipe. Here, you will prime/cement the no hub adapters to each pipe end so thet you end up with your overall measurement (remember you have deducted 1/2"...this allows for the no hub clamp rubber lip at each clamp).

Then slide the clamps over either pipe (ceiling or PVC) and install the rubber couplings on each no hub adapter. THEN (most important part here), bend the rubbers back onto themselves so that the pipe (with rubbers on) can slip in between the pipe in ceiling.

Then simply flip the rubbers onto the cast iron pipe and slide the clamps up and over the rubbers...tighten appropriately.

Then hang pipes as needed (may need to hang pipe prior to cutting pipe..so remaining pipe will not fall once cut).

Then test for leaks.

This should do it. If you have any more questions do not hesitate to ask away...but first do as Ballengerb1 suggested and rule out that it is not anything above the pipe that is leaking down and making it look like the cast iron pipe...He and I know that this happens quite abit!!

Hey, if my answer was helpful please RATE THIS ANSWER by clicking on button below...thank you!!

bjw0025

Thanks for the help, I really appreciate your time to give me an answer. I am a big fan of this website and will pass it along to family and friends

bjw0025

I am 99 % positive that it is a section of the cast iron pipe, when the shower hasn't been used for a couple days the tiles were starting to dry up. After using the shower a small water drip would appear around the pain trap plug.

ballengerb1

"pain trap plug" can you explain this a bit better?

bjw0025

Sorry, I had a typo, What I meant was a P trap plug

massplumber2008

The p-trap plug is connected to the bottom of a p-trap . It is sometimes removed to clean out a p-trap from underneath...I do not install these type of p-traps unless they are accessible via open ceiling or access panel.

If you have found water dripping around your p-trap plug then you will need to let things dry a bit and then get up and into the p-trap area with a flashlight and some toilet paper...Then have a friend run water and you take toilet paper and put it UP near the drain pan where the pan meets the pipe going into the trap. If toilet paper gets wet, then problem is at the shower pan or the shower drain assembly itself.

If that does not wet the rag then the problem could be the p-trap itself...again, use a dry piece of toilet paper if necessary and check to see if it gets wet...finally, if this does not produce wet toilet paper, then leak should be obvious at the p-trap plug itself. Sometimes can just loosen these...sometimes cannot!! Let us know what you find.

Also, if you are going to attempt to replace the p-trap you will need to add p-trap to list above AND you will need to be gentle cutting the vertical cast iron pipe to avoid disturbing the shower drain/pipe seal.

doug238

massplumber, you drop a used cast iron drain pipe in my living room, you will never be invited back. i disagree strongly with that advice.

massplumber2008

Doug...you should probably read whole thread next time...not much else to advise if bjw0025 is going to try to cut out pipes!! I did not suggest it...HE DID!!!