Installing hook on strange wall

Question

I need to install some hooks on my wall, which I plan to use to perform elastic band exercises. Hence, I need to install these very well so that they will handle the stress properly.

Situation is I have found an strange wall on the rental apartment I'm living. I was convinced it was a concrete wall because it feels sturdy when I hit it. Then I drilled a hole on it with too much ease. It's almost as if it is made of sand, and at some point (after 2 inches) the wall feels hollow while drilling.

My conclusion is that the wall thickness is 2 inches. At this thickness, I don't think the wall will be able to support the 3 sleeve bolts (5/16 x 2 1/2 inches) required to install this system.

I wonder if I have any alternative here, maybe using different screws? Glue? Any other method?

NOTE: Old building, perhaps 60's to 70's construction. Brick on the outside.

Answer 1

This sounds like old school plaster on metal mesh, common for that era in apartments and condos. Hard as a rock. However, you'd have to open up the wall to find the concrete block that's most likely behind it, because the plaster is only supported by furring strips tacked into the blocks with nails. Do not be fooled if your stud-finder scores a hit. Don't be surprised if you find none, they're probably small metal c channels.

I would not employ "any other methods" then the appropriate lag screws into a wood stud or masonry fasteners into their appropriate substrate.

Long story short, installing this correctly in an apartment of your construction is unlikely. You'll shot your eye out, kid.

Answer 2

Do you suppose your walls are covered with something similar to this?

http://www.aliexpress.com/item/Fiber-Cement-Board/1291501553.html

It doesn't sound like the wall covering is structural. There must be studs in the wall. You could try a stud finder device like you can find at your local DIY store.

You could try using toggle bolts. If you do, I would do a pull-test with something other than the resistance bands before hooking those up and getting too gung-ho with them.

If there are studs, but they're metal studs, those are basically sheet metal and they don't give you a lot to secure a screw into, so if that's the case, you probably still want to use toggle bolts.

On the other hand, if the walls are made out of something like Durisol, there might not be any studs. Durisol blocs are made out of a "cement-bonded wood fiber material."

Answer 3

It sounds to me like the internal wall construction is made of cinder blocks. These drill easily as you describe and a hole drilled into the wall would have likely entered into the hollow cavity of the cinder block.

I would strongly discourage you from trying to mount these brackets to such a wall as there is no good assurance that a strong pulling force would not break the face right out of a block like this.

Another consideration is that since you live in an apartment you most likely should not freely be drilling large holes into the walls. As a minimum you should seek the approval and advice of the landlord that owns and manages the property.