How can screwing a massively heavy object to a wall with four screws (like a water tank) be safe? I feel its always going to fall, taking a piece of the wall with it.

Question

Or screwing workout equipment which you constantly pull with your own weight.

EDIT: Forgot to add, I’m not in the US, I’m talking about brick or concrete walls, not drywalls. Although probably the basic principle applies when it comes to explaining how force works.

In: Physics

Answer 1

If you’re talking about masonry walls, it’s pretty simple. Masonry is really dense and strong. It literally is supporting a building. The 100 or so pounds is negligible as long as the screws can hold the weight. That being said I’ve never seen a fish tank hanging on a wall in a house. They’re generally on a stand because of how heavy they are.

But the basic answer is bricks and concretas are really strong. As long as you drill into them properly, they can hold a ton of weight.