I was trying to secure some bookshelves to the wall, and after using a stud finder to confirm it was drywall (and not a stud), I drilled into the drywall. I met some resistance, so, like an idiot, I switched to a wood screw and just drilled into what was there. I removed the screw and noticed that some black plastic was stuck in the threads of the screw; meaning I had likely screwed into a pipe.
The spot I drilled through is right in the center of a very large wall, so I didn't think it would be likely that the builders would place a pipe there. However, the house is 2 stories and there is a bathroom above the wall I drilled through.
There's no water spilling out yet so perhaps it is a drainage pipe?
All that said, am I screwed? What should I do to confirm that I did or did not hit a pipe? What's the best way to go about fixing this?
Best Answer
You likely hit the DWV (drain waste vent) stack. This is the drain plumbing for the bathroom and is commonly black ABS plastic.
This pipe is typically empty except when waste is moving though it. Depending on the size of hole, you may find small water spots that gradually get larger or notice a sewer gas odor in that room or nearby rooms.
It is not too hard to apply a patch material to the puncture to fix, but you'd need to cut a good size hole in the drywall to access it. The other option would be to enlarge the hole enough to get the tip of a caulking gun in to fill the hole and then patch the drywall.