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Author Topic: Installing projectors in a drop ceiling.  (Read 12057 times)

Joel Smith

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Installing projectors in a drop ceiling.
« on: December 18, 2004, 05:45:00 pm »

Im curious about the different methods out there.

At my company we take PVC pipe with two threaded adaptors.  One end attaches to the projector mount and the other attaches to a circular piece of metal that is threade in the middle and has screwholes along the outside.  The metal piece is screwed into two 1x4 pieces of wood that are connected by two smaller sections of wood.  The wood is cut to be longer than the ceiling tile so that the weight rests on the cieling frame.  Finally the ends are safetied off.  I posted a pathetic MS Paint representation below.



index.php/fa/859/0/
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Rob Timmerman

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Re: Installing projectors in a drop ceiling.
« Reply #1 on: December 18, 2004, 07:31:18 pm »

Yipe!  That sounds to me like an accident waiting to happen, for a variety of reasons:

1) PVC pipe is not very strong.  Threading any pipe greatly reduces its strength, especially in tension.

2) Screws into the narrow dimension of 1x4 can't be very large, or else they'll split the wood.  I'm not a huge fan of screws used in tension for rigging anyway, as they can pull out, or loosen easily.

3) The T-Bar frame for a drop ceiling is not considered structural.  It is NOT designed to support any weight beyond the weight of the ceiling tile, and while some loudspeakers and cable are supported  by the frame, they do not represent any more of a load than thicker ceiling tile would.  They certainly don't represent a point load of in excess of 10 pounds.

4) Not to mention he fact that untreated wood above a false ceiling may or may not be kosher with the building inspector, ditto on the PVC pipe.

I would be EXTREMELY hesitant about suspending an expensive projector using the method you describe.

Most projector installs I have seen either run steel pipe from the structural ceiling above the false ceiling to the projector mount, using appropriate fasteners at the top, or run threaded rod from the structural ceiling to a steel plate above the ceiling, to which the mount is attached.

Cutting corners on rigging to save a few dollars is not a wise business decision.  If a projector were to fall, and a lawsuit were to be filed against the installer, the costs of the lawsuit would far outstrip any cost savings gained by cutting corners.  Rigging is one place where you can't afford to cut corners.
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Joel Smith

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Re: Installing projectors in a drop ceiling.
« Reply #2 on: December 18, 2004, 07:52:30 pm »

Thanks for the reply.  I am relatively new to installations like this and when I was showed this method I knew there had to be a more professsional way to do it.  A couple of questions:

- Is this type of install violating a building code of any type?

- Does anyone know about any weight ratings for drop ceilings?

- How do you get 10 ft above a drop ceiling to mount the steel pipe while the drop ceiling is in place?

I will definitely talk with my employer about the situation and how severe it could possibly be.  

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Rob Timmerman

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Re: Installing projectors in a drop ceiling.
« Reply #3 on: December 18, 2004, 09:00:59 pm »

- Is this type of install violating a building code of any type?
It might.  I would check with your local building inspector, as he can give you the answer that matters.


- Does anyone know about any weight ratings for drop ceilings?
Since drop ceilings are not load rated, there won't be any definite load rating for the ceilings in general.  If you really need to know, you can check with a structural engineer.  But the load rating will vary from ceiling to ceiling, and will depend on where on the ceiling you are.  Anything under about a pound should be OK, but the way I would look at it is if it weighs enough to hurt you, even a little, if it were to fall, it's too heavy to trust to an unrated ceiling.

- How do you get 10 ft above a drop ceiling to mount the steel pipe while the drop ceiling is in place?
I'm not sure how common this scenario is, as that's almost enough room for another floor, but you really only have three options:  remove a section of the ceiling and use a Genie lift (or equivalent), use an A-ladder and have somebody skinny climb it, or put the projector in an enclosure on the floor.
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Hal Bissinger/COMSYSTEC

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Re: Installing projectors in a drop ceiling.
« Reply #4 on: December 18, 2004, 11:38:17 pm »

Does anyone know about any weight ratings for drop ceilings?

Drop ceilings are not rated to carry ANY weight other than itself. You will notice that all lighting fixtures, speakers and other items that apparently sit in the ceiling grid are really supported (or should be) from the building structure above by at least two independent hanger wires or chains. This is what the code requires. They also don't want all this junk falling down on fireman's heads if there is a fire and they have to pull the ceiling down.

As to how do you get to the structure 10' above the drop ceiling? Yup, as was said you have to disassemble enough of the ceiling to get a ladder or lift up in there.

Nobody said doing it right was going to be easy!

-Hal

Karl P(eterson)

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Re: Installing projectors in a drop ceiling.
« Reply #5 on: December 19, 2004, 12:20:36 am »

Let me also say that in addition to everyone else here. It is allot easier to do stuff in the cieling while the ceiling is going up. This may sound obvious, but some installers I have met prefer to just "let them do their thing, then we'll do ours". While its true it does require some work to coordinate cross-trade, its a skill we need to learn, use, and leverage to truly succeed in both efficiency and cost effectiveness for all involved.

Karl P

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Don Boone

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Re: Installing projectors in a drop ceiling.
« Reply #6 on: December 20, 2004, 10:08:16 am »

We use Chief CMA-440 when we have somthing in the way or it's a mile to the structure but we safety them off to structure or existing tie-up lines.

A 2x4 tile cieling is supposed to hold 75 lbs but only a fool would count on that.

BTW if you are using cast pipe flanges from the local home improvment store STOP.
Use only UL listed flanges.
We use Chief CMA-115s or more common now is CMA-345 'Ceiling Plate w/ Vibration Isolator' with the following disclaimer:

"Lighter projectors and modern construction
technologies have increased the likelihood
of image vibration induced by mechanical
(HVAC) systems.
Anti vibration equipment and installation
techniques are included in this offer but
these are included on a 'best effort' basis.
If additional material or services are required
to further reduce image vibration this will
result in additional charges"

Don
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Kurt Hansen

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Re: Installing projectors in a drop ceiling.
« Reply #7 on: December 24, 2004, 08:40:08 am »

I didn't notice where you're located, but here in Georgia if you fly anything over an audience as a permanent install you must have a certified structural engineer review and sign off on your design.

At a minimum, look at ATM Flyware for appropriate hardware, NOT Home Depot.

http://www.atmflyware.com/flyhome.html
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