Cast iron drain pipe too short after flange removal - what are my options?

[EthylOH]

Hi all,

I'm in the process of remodeling my bathroom. Since my old plywood subfloor had a lot of water rot, I had to remove it. This necessitated removal of the old cast iron closet flange.

Here's the problem...

The drain pipe inside the flange was cut way too short when they originally built the house in the 1960's.

The old floor consisted of 1x10 planks, 3/4" plywood, and then 1/8" tile directly on the ply. (total = 1 -5/8 ")

My new floor will consist of the 1x10 planks, new 3/4" ply, 1/8" Ditra, and 3/16" tile. (total = 1-13/16")

The drain pipe is approximately 1/4" below the plank floor, so when all is said and done, I need about 2" of depth just to reach the top.

I've looked all over the internet for options, and I can only find a few:

1) Cut the cast iron pipe, and add a no hub to PVC.

2) Drill out the lead in cast iron hub below and remove the pipe. Then add a rubber coupling for PVC.

3) Replace the flange with another cast iron flange and fill with molten lead

4) Use a push-in gasket fitting (Supply House has a cast iron flange: http://www.supplyhouse.com/Jones-Stephens-C47440-4-x-4-Two-Finger-Flange stock picture isn't accurate - it has a 4" throat)

Options 1 and 2 would be a nightmare due to the joist right next to the pipe.
I like options 3 and 4. I wouldn't be opposed to replacing it with another cast iron flange, but I can't seem to find them anywhere.

I've attached pics to show the problem. Any thoughts or suggestions would be appreciated.

Thanks in advance.

 

[Reach4]

You could check Sioux Chief 887-GPM PVC or 887-GAM in ABS against the ID of your pipe.

Take a look at an outside compression flange such as Oatey 42255 for short tail or this one from https://www.plumbingsupply.com/toiletflanges.html

 

[Sponsor]

 

[Standardairconditioner]

First, good job on the pics.

Many new members come here and provide no pics nor diagrams at all, which results in getting too many generalized answers, that I feel they don't even absorb and they just never come back, frustrated.

Before you work on that drain, remove (the section of) the floor you want to replace. It wouldn't make sense to repair the drain first with the rotten floor you'll be removing after.

Cut it at the joists, such that your new floor and old floor will share being fastened to the joist. Assuming the joist is 1-1/2" thick, the old good floor will rest on 3/4" of it, and the new plywood piece will rest on 3/4" of it.

For safety reasons, go ahead and continue the floor repair with a new piece of plywood, but don't fasten it in, so you can lift it off each day you work on the drain, and then put it back there when you aren't working on it.

With the rotten floor removed, you'll be able to see what kind of shape your drain pipe is in, and assess your options. Heavy grit sandpaper will smooth out the I.D. and O.D. surfaces of that pipe, so you can make accurate diameter measurements and see if you can use either a push-tite flange that will slide into the I.D. of your pipe (preferred), or a new cast-iron flange that will grip onto the O.D. of your pipe.

Don't get gung-ho and install that new flange too fast, you want to do that after you have laid your tiles because you want the new flange to rest over your tiles. Just test the new flange with a little bit of distance, ie., push it in just enough to verify dimensions, so you can still remove it.

 

[Jadnashua]

Since pouring a leaded CI joint is not typically DIY'er friendly, Home Depot is not likely to carry the parts required to make one! A plumbing supply shop that caters to pros probably will have the required bits. For a one-time use, the special tools required may mean paying a plumber to do it ends up cheaper, faster, and more problem free. The internal or external compression seals rely on the existing pipe being fairly clean and smooth...something that may not exist on a 50-year old installation.

 

[Cacher_Chick]

It looks to me like there is enough room to get in there with a snap cutter, which would make option #1 my choice. Snap cutters are readily available for rent, and all plumbing retailers sell the right banded coupler and flange to finish the job quickly. The deep set flange is a possibility, if you are willing to wait for it.

 

[EthylOH]

You could check Sioux Chief 887-GPM PVC or 887-GAM in ABS against the ID of your pipe.

Take a look at an outside compression flange such as Oatey 42255 for short tail or this one from https://www.plumbingsupply.com/toiletflanges.html

Thanks!

I saw that one online, but they wanted $75 for it.

How is www.plumbingsupply.com as a retailer? Are they a reputable place to order from?


This looks like my best option. It says it will reach pipe 3" below the floor, and mine will only be about 2".