Hanging chair - advice

Can't she just kick the chair away when she's ready?

Forget the vine eyes - much too lightweight. The magnodur one looks better, but I'd go for something like one of these

You is naughty! :)

Not enough detail supplied for the first fixing. As for the second one I do not think I would be happy hanging of something 4.3mm in diam. Either seated or otherwise. The 12G version is more a possibility you are talking of a material diameter of 6mm.

Richard

Try this:

My view is that joists are not designed to take point loads this way, the floorboards normally spread the load. Maybe that's over-cautious.

Is there a loft above which you can get to? If so, some 3/4 ply used atop some joists to spread the load is the way I'd go.

Assuming this is a ceiling joist (rather than a floor joist from the next floor up) I'd be wary about hanging a chair from just one unless it was near a wall plate. Unless the joist was particularly substantial I would (probably) fix a solid piece of timber or steel across the top of a couple of joists and then attach an eye to it. You could use some studding to bring the attachment below ceiling level, or make a feature by opening-up the ceiling and making a "pocket" for the thing to hang and swing around in.

There is a loft room above but putting ply on top of the joists will impact the floor above. Also concerned the thread would rip out of the 3/4 ply now thinking about it.

Another thought would be to screw some 8 X 2 between the joists (could screw through joists and into 8x2) with the 8" horizontal. Could then maybe bolt something through that to spread the load via a washer or something ?

I guess I could also screw some battens to the joists and then screw 3/4 ply on top of the battens. Then bolt something through that?

The joists are 8 X 2 in the ceiling of this room. They are the floor joists for the room above.

Although the latter fixing is rated at 100Kg (approx 15.5 stone) what is the maximum dynamic load of someone jumping into the chair? With 2 bolts to fix it without spreading the load could a single joist support the load, especially if fitted a large distance from where the joist is fixed to the wall?

The first fixing probably needs an area greater than the width of a single joist for fixing and it isn't wide enough to fix to two joists

In that case, get some steel U channel made-up to straddle the joist and extend below the ceiling, put a bolt (horizontally) between the two cheeks of the U and hang the thing off that bolt. Rebate the back of the floorboards above the U so that they sit flat.

Hmm, "straddle" isn't the right word. I mean a piece of steel that goes up one side of the joist, across the top and down the other side. It can be as long as you feel is needed to avoid a point load on the joist -

I tend to agree, also it very much depends on the size of joists and how close to the end you are. In Victorian houses the joists are typically very much more substantial than required. Is there a habitable room above? This may well have bigger joists than a loft. If not, and if it is a modern house (by which I mean less than 50 years old) then I would definitely be going into the loft and trying to engineer a support plate spread over two joists. It also has to be said, how heavy is your daughter (or her friends).

And, at the risk of being over-personal and/or vulgar, might it ever have multiple occupancy?

I wouldn't bet on that!

The peak load on a point source compared with one spread over a whole beam is IIRC 2:1 bending moment

Atypical chair with 4 legs is spread over only a couple of beams max, The floorboards don't really spread that much load further than that

won't spread a damned thing really. Far better to e.g. double up the joist the chair hangs from

Well ignore all the advice about strengthening them then

Way more than you need. Bolt through or *serious* screw in hook

If you are going to fasten something between the joists how about this;

Richard

That's the vase here. We still have the ~8mm OD screw-in-eye in the ceiling here in the lounge where we used to attach the baby bouncer thing (so it's been there nearly 30 years) and has had me and others hanging on it when testing the strength of stuff (like tree climbing harnesses). ;-)

I believe I just carefully located the sides of the joist with a stud finder, drilled a suitable hole to take the shank of the (pretty long) screw, put a bar though it and screwed it in.

It's about 1/3 the way across the ceiling in one direction and halfway across the other. We have had a king size waterbed in the bedroom above as well. ;-)

I think the main issue is using a strong enough fastener and ensuring it has a good enough structure to fix to. Here the load is spread to the other joists by some very substantial floorboards.

Cheers, T i m

When we installed the king size waterbed in the bedroom above the room the baby bouncing chair loop in the ceiling, we hung a plumb bob from the loop and over a metal plate laid on the floor, so that the tip of the bob was just shy of the plate. We filled the waterbed then checked the gap under the bob weight and it had hardly moved. ;-)

Cheers, T i m