I want to put up shelves in an alcove in my flat (old Glasgow tenement, red sandstone, large ashlar blocks externally, walls papered inside). Before fixing anything I'm trying to work out what the alcove wall is made of. What I've observed:
- Knocking on it, it doesn't feel like brick, but doesn't feel like wood either
- Drilled a small pilot hole: it drills very easily and produces relatively dark dust
- If I then push the drill bit (not running) into the hole, the material at the bottom feels spongy/elastic — definitely not wood
- Ran a neodymium magnet over the wall: it sticks at isolated points only, no vertical lines that would suggest studs
- The alcove is NOT formed by a chimney breast — there's no chimney in this room
- Previous shelves were screwed directly into this wall
I had a look at this guide and I found this picture.
What is this likely to be, and what's the right type of fixing?
BTW shelves will also be supported on the opposite side by a wood structure.
- Knocking on it, it doesn't feel like brick, but doesn't feel like wood either
- Drilled a small pilot hole: it drills very easily and produces relatively dark dust
- If I then push the drill bit (not running) into the hole, the material at the bottom feels spongy/elastic — definitely not wood
- Ran a neodymium magnet over the wall: it sticks at isolated points only, no vertical lines that would suggest studs
- The alcove is NOT formed by a chimney breast — there's no chimney in this room
- Previous shelves were screwed directly into this wall
I had a look at this guide and I found this picture.
What is this likely to be, and what's the right type of fixing?
BTW shelves will also be supported on the opposite side by a wood structure.
