What caused area of drywall to become as thin as construction paper?

Question

We attempted to hang a very very lightweight item on an area in an interior living room wall using a small nail, and found that there is no thickness/substance to a portion of the drywall. It was like putting a nail into a piece of construction paper, so as soon as a tiny bit of weight was put on the nail, it pulled downwards through the painted surface since there was no thickness to support the nail. The wall is a textured drywall, with several layers of interior paint. We just recently (a month prior) had the room painted. There is a tiled shower on the other side of the wall, including the plumbing to a shower head, but we see no sign of water damage on the exterior side in the living room (the area in the shower is tiled floor to ceiling on the other side).

We do have ongoing struggles with termites in other areas, but with those we typically find tunnels or small holes coming through the painted side of the drywall - and there is no evidence of that here. The area appears to be at least 4"- 6" side to side and top to bottom - big enough that I couldn't just move the nail up slightly to avoid it. (Finally resorted to using the command velcro strips to hang the item, in lieu of trying to nail anything into the wall.)

My question is what would cause the drywall to become so thin in a fairly large area like this - and is this of enough concern that we need to open up the area to look inside? We've lived in the house for 30 years and have never had the drywall patched or fixed for any reason in that area. Other than having the issue with the nail, there is no evidence of any issue with the wall. I hate to cut into the drywall (and have to repair that) unless there is a possibility that we need to be concerned about some other unseen ongoing damage occurring.

Any thoughts or suggestions?

Answer 1

There's been a time or two that I've repaired a 2-3 inch hole in drywall simply with paper tape and joint compound. There also exist drywall repair patches for damages larger than this but those usually include a metal mesh for strength. It's possible the area you've picked is repaired in such a way, but 6 inches is a long stretch to cover up with only paper.

You could reasonably cut the wall open in this spot, learn why it was soft, and then repair it with wood backing and a new piece of drywall. Given that the paint in the room is fresh, perhaps you have more of the same color batch and the re-paint of this spot would easily blend.

Answer 2

My first guess would be a goofball worker. Cutting into it you could examine the edges where it transitions from proper drywall, where that would probably indicate the cause. I've seen a drip-drip-drip roof leak that eroded ceiling drywall into just a membrane of paint without backing, but I have difficulty imagining a repeat of the pattern on a vertically oriented surface.

Answer 3

Also could have been the access point to repair the shower plumbing, but cheaply repaired.

Agree with others- cut it open and replace the sectiin to make it robust. Ideally cut half way into the stud depth so you can easily screw in the new drywall square.