ᐅ Slackline Attached to Garage Wall – Structural Issue or Not?

Hello everyone,
I have a garden, but unfortunately no large trees. However, I want to set up my slackline to practice walking again.
I’m considering attaching the line to two garages (both my own).
One is built with masonry (sand-lime brick and facing bricks), the other is a prefabricated garage made of reinforced concrete panels.
A slackline can experience tension forces up to 1.5 tons (worst case).
The attachment itself wouldn't be a problem: drill a hole through the wall, fix a steel plate on the inside, and then run a threaded rod with an eye bolt through the wall.

My concern is that the masonry or concrete panels might not withstand the 1.5-ton load.
The anchor points would be at the corner of each garage, not in the middle of the wall, at a height of about 60 cm (24 inches).
Do you think the entire garage wall will be pushed inward under such a load, or is that load manageable for the wall?

PS: Please don’t suggest hiring a structural engineer... that would be too much hassle just for a slackline.

Hey!
I recently found out that you can also set anchors in concrete in the ground and then tension the slackline using stands of different heights attached to them. Would that work?

Yes, I am familiar with that method. However, I don’t want to have an unsightly concrete-post standing somewhere when the slackline is not set up. The line between the garages would fit very well there, and the hooks would be barely visible. The only question is whether the precast concrete garage can withstand the load. I think I am less concerned about the masonry garage.

Of course, it would be possible to distribute the force with a larger metal plate inside. But how large does the plate need to be?

No, these are not posts sticking out, but just a hook that protrudes. My friends had theirs concreted into the ground, and then they placed a cover with artificial grass on top. (They used a sewer pipe with a lid.)
You can’t see anything once it’s disassembled. The slackline itself is then stretched over trestles to the desired height, and it is anchored to the ground from the trestle.

Try searching for "ground anchor" in an image search, and you’ll see what I mean...

You seem unfamiliar with the method since you talk about a post, while Wildthing refers to a foundation set into the ground with an anchor. So, there isn’t a permanent post standing there; it only appears when the bridge is tensioned.

A prefabricated garage like that is designed to support a vehicle resting on about four points, with a maximum weight of maybe 3 tons (if even that much). I believe it’s actually less. So, at most, about 750 kg (1,650 lbs) per wheel (not centered) is distributed across the floor area.

The walls are meant to support the roof—no more, but also no less. With a wall thickness of around 8 cm (3 inches), that’s not particularly substantial. A standard garage like this probably weighs around 10–12 tons (11–13 tons).

So: you certainly won’t be able to move the garage by pulling it, but what happens if you simply drive your car at the back wall with some force? Bumper first… that’s roughly 1.5 tons (3,300 lbs) rolling impact.

I would be very, very, very cautious, especially since you’re aware of the enormous forces involved.

In Austria, a woman was killed when she hung a hammock between a tree and a truly massive statue. She is now dead.

Consulting a structural engineer or using a statically sufficient anchoring system remains unavoidable. These are not forces a prefabricated garage can simply withstand.

Safety first!

Oh, right, I misunderstood that!
There’s probably some truth to that. So I could pour a ground anchor near the prefabricated garage. Do you think the masonry garage would withstand the force? The hook would be in the rear wall, right next to the side wall. In other words, the tension force would be transferred to the side wall... so basically the force would act along the length of the side wall...