Disclaimer, I don't know much in home improvement and I'm a bit at loss here.
I want to hook 2 patio umbrella holders (pic1) on my balcony. I thought the outside of the wall was a drywall because when hitting it, it sounds hollow. Consequently. I tried to hook it with dry wall anchor. I manage to put the anchor in but when trying to drill the screw into the anchor, the screw and the anchor went through it (pic2 and 3)
My 3 questions are:
- What is the material that I just went through ?
- How can I patch it ?
- Is there a solution to hook the umbrella holder (it will have to withstand potentially heavy wind)
Thanks.


