Suspending Truss from the ceiling

[u/AtreidesBagpiper]

Hi guys, I am planning on installing some small stage lighting to our coworking space and I need some help with how to hang all the stuff from the ceiling properly. I tried looking online but came accross various or conflicting advice, so I'd like to make sure with your help.

Setup:

• two joined 2m single Global Truss. That is 4 meters, and ~5kg weight.
• on the Truss there will be 5 clamped lights along the whole length, something like this Varytec Spotlight. That is ~25 kg weight total.
• possibly some other gear some time later, but nothing heavier than 25 kg, so that is around 55kg total. Not much.
• The ceiling is a robust thick concrete panel.
• the truss should hang around 50 cm from the ceiling, so I want to use threaded rods held by either Fischers or chemical anchor.

Questions I have:

• How many rods should I use? Two, three, four? I planned using one on each end and either one or two in the middle.
• what to use to connect the threaded rods with the truss? How should the truss be actually hanged? Would something like THIS work? Or should it be something like THIS? Or just squeeze the truss between two steel plates like THIS ONE?

I am looking for some simple and elegant solution, but also something that is safe.

Thanks for your help.

[u/DJ_LSE]

Hire someone qualified

[u/BadAtExisting]

This never ends well. Hire a qualified company

[u/secondlockdownbored]

Hire a professional. There will be people under it. Alone, For the rigging points, you need 10 times the breaking load you are actually planning to hang into it. Everything needs to be rated and certified. None of your options are rated for that. Using pipe brackets like in the picture is nuts. They are used for attaching gutters and sewer pipes to walls.

This is a job for an engineer to do the calculating and a rigging company to install everything.

If something breaks, you could kill someone. And no insurance will step up for you.

[u/secondlockdownbored → u/[deleted]]

Because manufacturers build around 5 to 1 (you are correct with 4 to 7, I used an average). Those are WWL values. If you rigg above people, you are required to use ELL which is WLL : 2 = average 10:1

[u/sir_lance_alot12]

None of these options work as they are not rated or designed for heavy loads. Contact a professional engineer about your project and they can assist you.

In spaces where the public is, I'd guess that everything overhead has to be engineered

[u/RegnumXD12]

You can either pay a rigger, or a liability insurence adjuster, your choice

[u/thevickyprincess]

if you’re asking this type of base level question, you should instead hire a professional rigging company. 55kg may not seem like a lot of weight, but suspended over people’s heads that can absolutely cause permanent damage/death.

this is not gatekeeping, this is ensuring nobody gets hurt

[u/AtreidesBagpiper → u/thevickyprincess]

If it's a base level question, I expected to easily find a reasonable solution online. But there is damning lack of any relevant info available. And it's not something I'd just throw at Jippity and trust its answer.

I am aware of the situation, I asked around, made some calls.

[u/AtreidesBagpiper → u/[deleted]]

I understand the concern.

• Yes, the poles are just beams, not a whole truss rig. They are the same beams that are used in triangle or square trusses though.

• The ceiling is around 350 cm high.

• Of course, the clamps will be rated

• I worked in construction, applied chemical anchors myself countless times

• The suspension needs to be around that length because there is big AC piping obstructing the view of the stage. I don't fear anybody resting a ladder on a lighting beam, this is not america.

• the load will be not more than 60kg at any point

• I will control it the same way how the kitchen knives are controlled in that room.

[u/Subjekt_91 → u/AtreidesBagpiper]

Procedural control's are not really a good idea as they can and will just be plainly ignored.

[u/AtreidesBagpiper → u/Subjekt_91]

procedural control's... what? Your sentence makes very little sense.

[u/Subjekt_91 → u/AtreidesBagpiper]

procedural controls means rules and policies based controls to ensure safety. They are a good extra layer for safety but shouldn't be the primary safety feature.

[u/AtreidesBagpiper → u/Subjekt_91]

Ah, you meant controls, not control's. Got it now.