Attachment of PVC Pipe to a Structural Post

Kat9898

Member
Joined
Oct 21, 2019
Location
Evanston
Hi all, I just wanted to thank all of your for your advice and time before hand!

I'm currently working on a play and the set designer wants there to be a PVC post that connects from two upright poles in the set, and also two structural posts in the building where we are working. I've attached some preliminary set design plans and I've circled the PVC pipes in question in red. The longer of these two PVC pipes is 13' long, to get an idea of the amount of weight that will be put on the structure. We currently don't have a selection for how thick the pipe will be.

The problem is that we need to figure out how to attach the PVC to the structural post (approximately 7"x7" square) so that it doesn't slide or wiggle throughout the performance. The current idea is to make a kind of jig using two pieces of 2x4 and two bolts in order to make a tight square and then attach the PVC to the wood. (pictures attached of this method as well) I think this will work well but I just wanted to see if any of you had any other ideas!

Thanks again for all of your help!
 

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eadler

Well-Known Member
Joined
Sep 17, 2010
Location
Upstate NY
I'm not qualified to talk to the structural portion of this based upon the information provided.
PVC does tend to flex/sag when it gets warm like it may under the glow of incandescent theatrical fixtures (especially over longer runs as there's more weight). Are you sure you want to use PVC?
 

Van

CBMod
CB Mods
Premium Member
Joined
Jul 27, 2006
Location
Portland, Or.
Your PVC pipes are not structural correct? You are 'attaching to structure' but not introducing any significant load to structure. As long as you do not penetrate the structural or in anyway deform it you can do whatever. I like the idea of the wood blocks then you can screw straight through the PVC. as Eadler said, PVC can be saggy under stage light so make sure to put a little tension on them if possible.
 

lwinters630

Well-Known Member
Joined
May 12, 2011
Location
west of Chicago
As stated I cannot speak to the structural. But I have mounted 2" PVC by cutting a round disk to fit inside glued and screwed to a larger plywood disk to fit on the out side (like a a curtain rod or bottle top). Screw the large disk to the 7x7 post and put small screws through the PVC into the center wood. 3" or 4" can use a toilet flange.
I do not think PVC will be rigid enough to span 13 ft if it is under 3".
 

JonCarter

Well-Known Member
Joined
Apr 18, 2011
Location
Meridian, Idaho, US
If the two circled pipes in your drawing are 13' long they will definitely sag if supported only at the ends, even if you use pipe such as 3" or 4" schedule 80. (You don't say what the item across the "back" ends of the two 13' pipes is or what is supporting it.) May we assume that the upstage ends of the pipes are supported somehow and that there is something accessible for support above these pipes? (Such as, maybe, a lighting grid, ceiling or structure of some kind?) If so you might consider black iron wires about every 3' or 4' from the 13' pipes up to the "something."
 

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