Hanging from Concrete Block

[akaCat]

quadriplegic, but still alive. Still terrible. found it down the rabbit hole of googling hammock fails. best to stick with posts.

There must have been at least two girls involved in brick-support hammock accidents last year. The young lady in the news article oldgringo linked to did die.

[MrGhoti]

There must have been at least two girls involved in brick-support hammock accidents last year. The young lady in the news article oldgringo linked to did die.

Just checked again, you are right, my google search-fu failed me again. just read the story from 2016, that is terrible. the one I read the other day appears to be a couple years old, now that I looked back.

[Just Bill]

I would tend to agree that a mid wall point load is a bad idea.
That said- the corner of a block wall garage will have much better resistance to a lateral load and should be fine.
Putting a single point, mid wall, with a backer block is almost worse... you're basically pointloading a single block. Your improved connection is only ensuring the anchor won't blow out of the block...

Are you excessively heavy?

Is the 6x6 post "in line" with one of the corners? (or close enough)

I would go get a treated 2x6 @ 14' long and cut in half. Nail it up into a T shape. Then attach the T to the corner of the block, with the top of the T facing your post with one 3/16" tap con screw per block, per side staggered. About 6-7" O.C. Try to hit a combination of block and mortar joints for the best screw values.
Put your eye bolt right into the top of the T. The wood T will spread the load so you aren't bearing on any single block (not to mention the T itself is probably enough to support you on it's own). The Tapcon's will prevent the T from falling off the wall, and using multiple screws means you will have little shear value on any particular screw or block. Being on the corner you also have the shear value of the wall you are in line with, and the bracing value of the adjoining wall and the interlocking corners of the block at that corner. Also- if you move out- you can just back out the tapcons, put a dab of caulk in the holes, and paint the corner.

Unless you're well over 300lbs though it seems more than reasonable without inspecting the block myself.
Unlike the girl mentioned- that is structural block, not face brick. You aren't going to be under the garage if it collapses either.

If none of that makes sense or you are confused- sink another post. In your yard. Trying to sink a post right against the garage could disturb the footing/base if is crappy masonry work.

[Grumpy Squatch]

I agree with others: a separate post is probably the safest. But, a concrete block wall is different than a brick pillar.

You need to be concerned with the strength of the individual block you will anchor to - was the block made with sufficient concrete strength so the block doesn't blow out with the load? Was the wall built with a 1500 psi block or a modern 2000+ psi block? Or some old "cinder block" from 50 years ago that might be lucky to be 500 psi? Are any blocks showing signs of water damage (spalling or blown faces)? Assuming the block is sufficient, you would be wise anchor at or near the corner - the strongest part. If near to the center, through bolt to a backing plate of sufficient size to spread the load across at least the multiple cavities of a single bloack or across many blocks. A steel plate 12" x 12" or larger, a long vertical bar, or a large plywood backer should should work. Best to spread the load to the sill and top.

Then you need to worry about the wall integrity as a complete system. Are the mortar joints solid? Is the wall plumb or is it bowing? Are there any cracks suggesting shifting of the foundation? Are the top and bottom secured to the foundation and other structure sufficiently? Are any of the cavities filled or is it truly a hollow wall? If the wall has sufficient integrity, then I'd bet you could anchor a hammock safely. While it's true concrete blocks and walls made from them are strongest in compression, a well-built concrete block wall can sustain considerable transverse or lateral loading - that's why people still make foundations and retaining walls out of them.

Get a good anchor and through-bolt system. Something designed for safety like the Climbtech swivel and backing plate here: https://www.climbtech.com/swivel-anchors/. Hang a hammock with sufficient suspension sag (>30°) to reduce the lateral load as much as possible. Don't treat it like a toy and let someone string a straight wire and then load it creating 1500+ lbs of lateral force on a single anchor point. Even a big guy like me, with a properly hung hammock, should put no more than 300 lbs. of force on the anchor, and some of that force is actually a shear force on the anchor and not purely lateral.

I'd argue that if your wall can't handle a 300 lb. lateral force, your garage is dangerous and should be torn down.

As always, your mileage may vary, this is only my opinion, decide for yourself, and don't hang anywhere you aren't prepared to fall from.

Good luck.

[Rain Man]

I agree with the warnings about lateral forces on masonry walls (and any structure, for that matter), which can be surprising powerful to a layman.

One other thing, which I don't think I saw mentioned, is the option of adding an overhead structural member (a pipe, "T" piece of lumber, etc) to take some of the lateral force between the two anchor points. It would run parallel to your hammock and from one anchor point at your feet end to the other anchor point at your head end. The forces from the two ends toward the middle would tend to "squeeze" this member, which would be subject to bowing, so it would have to have strength to be stiff. Otherwise, it wouldn't really help much.

Perhaps you are already familiar with this option?

[gargoyle]

Unless YOU were involved in the actual construction process of the (I.E. were proper and legal practices used throughout the ENTIRE construction phase) block wall, do not hang from it.

Things like filled cores, reinforcing wire, rebar, foundation attachment, bond beams and roof attachment and other proper practices can be in place?? Techniques used in hollow core block construction vary greatly. Nobody can speculate from afar the safety of YOUR wall, since they were not the builder. Period.

Freestanding support should be used

[youdigit]

I perhaps should have been clearer - basically, both the parallel and perpendicular walls will be holding the load (anchoring just on the inside of the corner), through the shelving unit on the inside of the garage, which is anchored to the wall at multiple points (both parallel and perpendicular). The shelf is really deep, so there is about 4ft of wall (parallel to the hammock direction) that would be holding the load. In short, no single block is holding is intended to hold the load; I intend to have mostly the parallel wall hold the load.

I would love to sink another post over on the other side, but for various reasons (i.e. a huge concrete pad under the yard over there AND me being too lazy to dig up 1ft of dirt and smash it out..) I can't. I only have about 14ft total to work with so not a ton of space to move it around.

[Phantom Grappler]

If you decide to hang on the wall---
Maybe hang from a sill--I might be using wrong word--a bond or board running length of wall--sitting on top of wall and connected to wall and roof?!?!?!
Are you renting or buying? If buying do you own it--or making payments?
Above all--have fun.
Fun for me--is nothing goes wrong
While fun for someone else might be conquering challenges with some risk as a form of intellectual pursuit.
Good luck HYOH


Sent from my iPhone using Tapatalk

[Tyler883]

A turtle dog stand is safe, yet walls,trees and posts have been known to kill people.

If you build your hang with a ridge pole borrowed from a turtle dog design, you can rest well and safely.

Isnt that what hammocks are all about?

Sent from my SM-A500W using Tapatalk

[Floridahanger]

Even a board on the inside needs to be secured. You may want to bolt it to each row of block/brick to ensure the entire height of the wall works as one unit.
Good luck in your backyard hang pursuit.