Hanging Chair from Ceiling in Apartment?

Question

I bought a macrame hammock swing chair and a steel plate ceiling mount that came with 4 big expansion screws (pic #1 is chair i bought, pic#2 is mount with included expansion screws. Mount is size of palm). I found the ceiling joist(joists are wood) and marked where I want the plate to go, but When I looked up how expansion screws worked, I realized that expansion screws can't work if you drill into the joist because the wood stud prevent the screw from expanding behind the drywall. The steel mount can hold up to 440lbs, the chain I got holds up to 1,000lbs. Iam a heavy person. 230lbs so I don't think I will sit on it but I'm hanging it for my kid who is 100lbs. I need to make sure when I mount this, it holds a lot of weight.

So, I have 2 questions:

1. Will the ceiling be able to hold a standard adult weight using the expansion screws if I don't use joist? ( else why would this be sold as ceiling mount for swing chair if ceiling could not hold the weight?)

2. If ceiling alone can't hold that weight and it's best to use joist, what type of screws would be best to mount the plate into the joist to hold a lot of weight?

I just don't want to mess up, do it wrong and rip out the ceiling when my kid goes to sit on it because then I'd be back here posting more questions about how to patch a hole in ceiling...haha...please help!

Answer 1

Expanding on the comments already in place:

1. your ceiling absolutely cannot hold that chair without anchoring into a joist one way or another.
2. You are correct, the expansion screws will not work for your situation in any way.
3. You say "apartment"; be aware that many leases take a very dim view on large holes in walls and ceilings even if all does go well.

isherwood's link leads to lots of good reading. Basically, unless you can attach to a plate above your joist (for example, if the floor above is an attic), your chair needs to anchor to the joist or to something that is itself anchored to one or more joists. That usually means a wood screw or lag screw. There are calculators that professionals use to determine pullout strength such connections (example), but a fair rule of thumb when you're driving screws so that at least 2" of thread makes it past the drywall into what you ESTIMATE is the center of PROBABLY generic spruce/pine/fir joist that you HOPE is in good condition: no more than 100lbs for each of those screws.

True, a 5/16" lag screw well-placed in good lumber can reliably hold four times that much. But keep in mind how easy it is to be even slightly off in placement, or at an angle, or in a soft spot of the joist... a less than ideal screw might hold LESS than 100lbs. Behind the drywall, you have no way of knowing until there's an expensive cleanup at best and a trip to the hospital at worst. This is especially true for things like a swinging chair, where the forces on the connector of dropping into place and moving can be several times the static weight of the person.

This is by no means impossible. But it is substantially more involved than hanging a potted plant or a lamp, and will require some careful consideration and an obliging landlord.