Old diamond metal lath plaster ceiling strength for supporting heavy loads?

Question

I am an avid DIYer and have been renovating a space in an old commercial space from the 1950s. It is a hodge-podge of various building materials over the years. In our space is, from what I gathered from searching, the ceiling is a suspended diamond metal lath plastered ceiling like this:

I have been hanging lighting fixtures and ceiling fans using metal toggle bolts like these:

They seem to work fine. There used to be a grid drop ceiling attached to the plaster ceiling and they used similar toggle bolts with an eyelet on the end to attach the wire from the grid to the ceiling, so I know it can support one of those grid systems with the Styrofoam panels if the weight is distributed, but I can't imagine that is a lot of weight.

Unfortunately, I don't have access above the lath plaster ceiling to access the metal joists. What I would like to do is install a bar that would allow TRX bands and/or punching bags to be hung. Obviously, this would need to support a lot of dynamic weight.

This shows something like I had in mind. Mine would be longer and need to support 8-10 people using it at the same time with the suspension bands. I was also considering a "T" in the middle with another support to the ceiling.

Is this crazy? If I distributed the weight across a long span (2x4, 2x6, etc), would this work. I would use the snap toggle bolts which support 150lbs and I would use one every 12-18 inches (no science there, just want to go overkill) across the wooden beam in to the metal lath. I'd then attach the pipe to that beam, similar to the picture.

If this won't work, any suggestions short of opening up the ceiling and seeing where the metal joists are? I don't think I will have that as an option.

Thanks!

Answer 1

Are you talking about hanging a workout style bar, on hollow wall anchors... on plaster? NO, NO, NO, that is a horrible idea. Plaster crumbles, and the performance on a wall vs ceiling will be different. Just like concrete anchors do not perform as well over head. You need to secure the bar to structural framing, and I personally would want the 2x6 secured across multiple joists, so as not to add a single point of stress on just one joist.

... wait a second, ceiling fans? That is insane! It's one thing to use hollow wall anchors, which the manufacture approved for a plaster and lath ceiling... but not for a dynamic load. Ceiling fans are such a load, the code requires that fans are secured to structural framing. If you want to use the toggle or molly bolts, to secure an electrical box which is only going to support a lightweight fixture ... go right ahead, but not for securing a fan.

You MUST do what you don't want to do, it won't be that bad, and nobody will hurt themselves or destroy the plaster ceiling. Not just for the workout bar mind you, but for those fans that could kill or maim, and you'd be liable.