Drywall screw in copper drain pipe

[JSMI]

Hi everyone. First off thank you for everything you post here. I have learned so much from this site over the past 15 years as I've plumbed homes I've lived in. I have never failed an inspection because I carefully read everything you post. Thank you all!

My home was built in 1960 so it has a lot of 3" copper drain pipes and some cast iron, too. All is in good shape, but...

Back in January, some drywallers were finishing a ceiling in the basement and they drove a screw through the 3" copper main drain line. Nobody noticed until a week or two ago when a leak appeared and made a wet spot on the ceiling. The drywall screw finally rotted away and let water through.

This pipe is fairly immovable, so I can't cut it once and get a Fernco fitting on it. I think I would have to cut it twice, slide one Fernco fitting to the left, one to the right, then put the cut pipe section back in place, then slide and tighten both fittings.

I think that's best since I'm going to patch the drywall and don't want to redo a temporary fix. Before I cut the pipe, am I fixing this correctly? From what I've read, things like plugging the hole with solder, epoxy, various goos, or a hose clamp/rubber contraption won't hold forever.

I couldn't figure out how to upload a photo here so I used imgflip to make a meme...

 

[Reach4]

I am not a plumber.

To go over 3 inch copper, I would get a Fernco 3003-33 or a PlumbQwik P3003-33 or a Mission K-300

I would remove the metal band. I would slice the rubber on one side, and place the rubber over the hole. I am not sure if I would put the slice on the far side or on top. Probably does not mater.

Then I would spread the metal band/shield and put that over the rubber. Tighten to 5 ft-lb. Will hold nicely and look nice. It will hold forever.

 

[Sponsor]

 

[wwhitney]

I would remove the metal band. I would slice the rubber on one side, and place the rubber over the hole.

I think you'd have to also cut away the rubber stop in the middle of the coupling. Could be hard to get it flat. I'm not sure if there's a source of stopless rubber couplings of the correct size, that would be very convenient for the repair you propose.

Cheers, Wayne

 

[Reach4]

I think you'd have to also cut away the rubber stop in the middle of the coupling. Could be hard to get it flat. I'm not sure if there's a source of stopless rubber couplings of the correct size, that would be very convenient for the repair you propose.

Good point...

There is also "FiberFix", " Pow-R-Wrap", "J-B Weld FiberWeld" and "Quick Seal".

 

[wwhitney]

I'm not sure if there's a source of stopless rubber couplings of the correct size, that would be very convenient for the repair you propose.

I think the Fernco 1056 series has no internal stop, so one could use a 1056-33RC. That's a single size for 3" Plastic, CI, or Copper, so it's a bit oversized for copper, a thin longitudinal strip could be removed to make the rubber fit better, since it would be slit anyway.

Alternatively, a 3" copper DWV repair coupling (no stop) could be cut and soldered on for a repair. If one could figure out how to hold it in place for soldering around all the edges, just 45 degrees of it would be enough to cover the hole. Or cutting it to 210-270 degrees should let it be snapped onto the pipe, possibly with a metal clamp to hold it in place. That would require greater access for soldering the full perimeter.

I think there are techniques for filling small holes with solder or brazing, but I'm not familiar with them.

Cheers, Wayne

 

[Fitter30]

Know any air conditioning service people. Could remove the screw with shop vac suck the water out and solder hole close with either Harris dynaflow or 15% phos copper using a airplane torch ( oxy/ acetylene) need alot of heat concentrated with a small rose bud tip.

 

[JSMI]

Thanks for the replies. I had considered getting one of those shielded Fernco fittings, slicing, wrapping, and tightening. Wasn't sure if that would be a good fix. But since it was suggested here, I went and found a Fernco fitting without a stop -- the 2-hose-clamp kind, not the shielded kind. I sliced it, took off an extra 1/8" or so to make it squeeze tighter over the copper, and it looks like it'd work. I'd add a 3rd hose clamp right over the screw puncture and tighten that one first so the Fernco completely/tightly covered the hole.

I'm thinking about getting a 3" copper coupling, cutting a piece off, clamping and soldering. But that's a mail order only item... nobody stocks copper or brass DWV fittings near me. Might be easier to just bend or hammer a scrap of 3/4 copper and use it as a patch. But even then.... is the copper thick enough, will my torch heat it, will it seal forever.... Although I've done hundreds of 1/2, 3/4, and 1" fittings, this would be my first rodeo soldering old 3" copper.

If it wasn't for the finished ceiling, I wouldn't overthink this. Just don't want to cut the ceiling open again down the road....

 

[Reach4]

I'd add a 3rd hose clamp right over the screw puncture and tighten that one first so the Fernco completely/tightly covered the hole.

How about taking the shield from a shielded coupling with a stop, and covering your no-stop rubber?

 

[JSMI]

I looked for shielded fittings, but I only found an off-brand one that had a tin-foil looking shield. It didn't look very strong. Fittings are getting harder to come by these days...

Before adding the Fernco, water would pour out of the screw hole when I flushed a toilet upstairs. With 1 hose clamp over the Fernco, there's no water, not even a drop. I'm gonna let this sit for the day and see if any water comes out. Then add hose clamps to each side, working out from the center, to prevent the Fernco from bubbling. I think this'll hold.

 

[Reach4]

I looked for shielded fittings, but I only found an off-brand one that had a tin-foil looking shield. It didn't look very strong. Fittings are getting harder to come by these days...

I don't think you would need the shield from a P3003-33 necesarily, but could use the shield from a different 3-inch unit such as P3001-33. It may be presumptuous, but I suspect many couplings share the same shield but differ in the rubber.

Have you checked the websites of your nearest HD or Menards? HD site is nice in that they show how many in stock and which bin... presuming their inventory is ok. Menards shows a quantity but not a bin location, but you can probably find the area.

 

[JSMI]

I checked the websites and they're only available 30+ miles away, and often they're not there to begin with. Shelves have been rather bare here since May or so. Not sure if it's mid-Michigan, all of Michigan, or the whole country.

 

[Reach4]

I checked the websites and they're only available 30+ miles away, and often they're not there to begin with. Shelves have been rather bare here since May or so. Not sure if it's mid-Michigan, all of Michigan, or the whole country.

For $10, many places will ship, and save the hour round trip of driving... but it will take a couple of work days. Plus at the store you get to use your digital caliper, and compare to what you need.