I'm considering attaching a new towel rail to the drywall in my bathroom, with attachment points approximately marked by the yellow postit notes in this picture.
This is on the 21st floor of a condo building in Montreal (built in 2014). The building manager said the drywall is approximately 1" thick (a full inch! not a centimeter).
Is this really possible? (I haven't been able to get confirmation from anyone else).
If the drywall is really 1" thick, will the usual drywall anchors be effective? Usually the pictures I see of drywall anchors have them exceed the thickness of the drywall by around 1/2", and have expanders which end up significantly expanded after the screw is inserted. However, most anchors are at most 1" long, and in a 1" thick drywall, there probably won't be much room for the expanders to expand. Will this decrease the effectiveness of the anchors?
Another issue is the nearby thermostat/light switches. How do I make sure to avoid any of their wiring when drilling in the drywall anchors? Is it important to avoid them? Part of this I suppose comes down to how the wires are arranged behind thew all. Will they for example come bundled in a metal tube? (In this case hitting the metal tube may cause the tube to flex undesirably?
Is there anything else I need to watch for? How can I tell if there's plumbing behind the wall?
If I gently drill a small hole, poke into the hole with a toothpick and check there's nothing within an inch behind the wall to worry about, is that a guarantee I'll be fine?