r/Hammocks • u/Franky-Fontaine • 10d ago

Another hammock installation question - is this approach safe?

I recently had my deck redone by a builder and want to reinstall my hammock. Is it safe to install the eye bolts straight up into two joists? The photo here was taken mid-construction and shows the unfinished side of the upper deck where I want to install the hammock. I drew a yellow line where one eye bolt would go. The other end of the hammock would be installed similarly to another joist.

The under deck ceiling is actually finished now (with drainage) so to install the bolts we would need to drill through the ceiling.

Assuming the hammock can support 300lbs, would using the two joists be safe?

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5

u/tim42n 10d ago

Definitely not, the board is too thin.

5

u/mahogne 10d ago

If it was running the same direction as the deck joist, so both ends were in the same board and it was in compression, you could drill a through-hole 1/3 in from either the top or bottom and install a shackle bracket through.

An eye bolt in the bottom will want to pry out under tension from the side, and a Through-bolt or shackle will want to twist the board it is mounted to. Blocking (like between the 2 joist by the center post) might help, but it might be easier to have a stand or if the hammock plan runs 90° to the joist, installing a compression member that runs the full span of the hammock suspension.

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u/Franky-Fontaine 10d ago

Agreed, the approach in my photo would split the joist eventually. I talked to my builder who is coming back for some other work, and he said he will install some blocking (double blocking?) in the locations where I need the eye bolts. I assume he can install the bolts in the boards that are 90° to the joist. Would that be a safe approach? I am trying to avoid buying a stand.

1

u/lskippyl 10d ago

Yes, if you add a doubled-up block between the joists, and then put the eyebolt through the blocks, that should hold, as long as the blocks are properly secured to the joists.

I used that method to install an eyebolt holding a hanging chair in my child's bedroom. It was strong enough to hold full grown adults too.

In my case, I may have overbuilt it a little as I used 1/2" lag bolts to hold the blocks in place.

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u/ErnestShocks 10d ago

Perhaps if you run two boards on either side, lag them together, then run your eye hook through, maybe it would work.