What kind of fastener do I need to attach this securely to the studs in my garage?

Question

So, my wife bought my daughter a "Home Gym Yoga Hammock" which is basically a large swing that she'll do exercises in. The intention is to hang it from my garage studs so she has a place to work out; she's a dancer and her normal routines have been badly disrupted by the studio closure due to social distancing needs.

However, the installation video shows how to install it in concrete, and then cuts off right as it's about to cover how to install it to wood (sheesh...). The included hardware is, I believe, concrete fasteners, and it's my understanding that they won't be durable if I try to insert them into wood studs - certainly not for my daughter's weight while she's exercising. Of course if they come loose she could get badly hurt, so I need to get this 100% right. She's 5'8" and essentially fully-grown, so don't think "only supporting a child's weight".

Here's a picture of the mounting plate, and two of the bolts (one assembled, one disassembled) that came with it.

What kind of fastener do I need to properly secure this to my garage rafters? Edit: note that my garage has a drywall ceiling on it, so I’ll need to pierce the drywall and drive into the studs.

Answer 1

knowing that there's a floor above adds confidence that the beams above the ceiling are strong enough.

but you're going to need to determine how your ceiling is contructed.

Either the drywall is attached directly to the floor joists in which case a stud-finder will help you determine where to screw or the drywall is attached to battens which are run across the joists in which case it will not give a usable result.

If the floor joists are directly above the drywall use structural screws to screw the attachment point into the joist

If there are battens between the drywall and the joists loctate the fixture where the two cross and use longer screws to attach through the batten (or through the air if the batten is too narrow) into the joist.

I would use #14-10x65mm Timber Tek screws in the first case and the 100mm version in the second. These screws are each good for over 380Kg force (850 pounds) in pine, more in hardwood. This is an Australian product, but there's probably something similar available in your area.

Answer 2

If you have access to the studs, rather than fastening through a wall covering, you can assure strength by sistering to the studs.

If you use bolts instead of screws, you can make use of washers and nuts to add tensile strength where it is most needed. If you have access to the top side, you're all set. If not, rip the added segment to be narrower, you'll have room behind the piece to add washer and nut.

To manage the full diameter of the fixture, you may have to add a sister to both sides of the stud.

Attach securely the sister piece with screws and if you want additional security, add a quality glue. I tend to the belt and suspenders over-engineering school of thought.

You're correct that the expanding anchors will not perform well in wood.