I'm Scenic Designer on our upcoming high school Musical, Grease. Now I have the set designed with a platform that is 16' long x 10' wide x 3' high. The plan is for the pit to to reside on this platform. I figured I would build it from four 4'x8' and two 2'x8' platforms build from 3/4 plywood and 1x6. Now this is going to hold about 12 people plus a drumset, keyboard and a couple amps. I'm curious if anyone could give me any tips on building this so it is solid and safe. I am aware of how to properly leg it with compression legs and bracing but I have my doubts.
Platform Safety
- Thread starterBLengyel
- Start date
I'm assuming you mean 2x6 structural lumber?
I sure as heck wouldn't get on it if you built it out of 1x6's with 12 other guys!!!
12 guys x 180 lbs each = 2160 lbs. Plus instruments.
When you screw that 3/4" ply down on the 1x6, its going to split.
I'm really hoping you meant 2x6!!!
You took the words right out of my mouth.
What the OP has going for him though is that the load is going to be distributed across 160 ft^2 -- not evenly, but it certainly will not all be concentrated on a single 4x8 platform.
yes I mean 2x6
1a. Use 2x4 instead of 1x6.
1b. Three toggle s per platform, on 2'-0" centers.
2. Rather than individual compression leg s, use knee wall construction. See http://www.controlbooth.com/forums/scenery-props-rigging/5191-my-platform-system.html .
3. I'm not sure 16'W x 10'D is large enough for 12 musicians, comfortably. I'd tape it out in the rehearsal room with all the players and their instruments, amps, monitors, chairs, music stands, mic stands, other gack, just to verify.
4. You're going to want toe rail s and handrail s on at least three sides.
1b. Three toggle s per platform, on 2'-0" centers.
2. Rather than individual compression leg s, use knee wall construction. See http://www.controlbooth.com/forums/scenery-props-rigging/5191-my-platform-system.html .
3. I'm not sure 16'W x 10'D is large enough for 12 musicians, comfortably. I'd tape it out in the rehearsal room with all the players and their instruments, amps, monitors, chairs, music stands, mic stands, other gack, just to verify.
4. You're going to want toe rail s and handrail s on at least three sides.
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I do realize that it isn't enough room but we told the music instructor he was going to have to suck it up and cram it in because we are tight on space as it is because we need the space for dancing. but it's always possible we can give him 11 or 12 feet width and we taped that out with 12x16 feet can work.
Do you still think it could be doable with compression legs? Because I don't think we have the time for knee wall construction or the funds. I'm guessing I have around a grand to burn on lumber and I would really not like spend all of it for the sake of costumes.
Tex
Active Member
The keystone idea is better than not doing it at all, but part of the strength that comes from Derek's approach is that that is fully tied to the frame all the way around, it effectively locks that into a square shape that it can't rack out of. With the Keystones you could still get some deflection in the wood, the full square of lauan will keep it rigid and prevent that flex.
I'd like to throw a few things out there.
A. With proper legging you could leg this platform with 1x4. 1x6 would be more than adequate. 2x6 is overkill 2x4 would be, sort of Goldilocks. < just right>
The whole Idea with Compression legs is that half the leg overlaps the framing. This help fight against torsional stress or "wracking".
I alway prefer a Knee wall system when and if possible. Remeber that you are relying on the compression of multiple 'studs' in a kneewall system, you can use 1x4 all around for light loads like this. Since this is a taller set-up you would want to either place stretchers < like old fire breaks> in the center of the studs this will keep the stud from bending under pressure, Or make sure your cross bracing is tied to each stud. < Don't like this idea as much because it bypas the center of the outer studs.> I would suggest using 2x4 as the outer stiles in either case.
A. With proper legging you could leg this platform with 1x4. 1x6 would be more than adequate. 2x6 is overkill 2x4 would be, sort of Goldilocks. < just right>
The whole Idea with Compression legs is that half the leg overlaps the framing. This help fight against torsional stress or "wracking".
I alway prefer a Knee wall system when and if possible. Remeber that you are relying on the compression of multiple 'studs' in a kneewall system, you can use 1x4 all around for light loads like this. Since this is a taller set-up you would want to either place stretchers < like old fire breaks> in the center of the studs this will keep the stud from bending under pressure, Or make sure your cross bracing is tied to each stud. < Don't like this idea as much because it bypas the center of the outer studs.> I would suggest using 2x4 as the outer stiles in either case.
kicknargel
Well-Known Member
1x6 IS an acceptable method of framing platforms. If they're in good shape I'd leave them alone. If you have to rebuild some anyway, 2x4 is cheaper and a little easier to work with.
Yeah I wasn't sure, You see My recently retired theater teacher with about 30 plus years of theater experience framed all of her platforms in 1x6 and she told me that it should be good. I think what I just need to do is the best but proper method of legging it and bracing . Do you think I could leg the 1x6 platforms with the kneewall method safely?
I'm not trying to be rude but do people really do this? Is it common to find platforms out of 1x? I was always taught to use 2x stock, most of the time 2x4. The couple of times I've seen 1x4-1x6 framed platforms in the real world they have seemed way too light and not strong enough to take any real abuse even if they are legged and braced nicely. I mean as a carpenter I use 1x all the time to make furniture but I'm also not jumping on, dancing on, or generally beating up my tables and stuff. It just strikes me as I'd rather have the added strength and thickness of a 2x4
Most of my platform frames are 1x8. With proper blocking they are perfectly safe for construction, and knock down for storage. Our last 1x8lasted almost 30 years before we retired them. A pair of 1x4's joined in a hogstrough are stronger than a 2x4 in compression, closer to a 4x4.
There are other construction techniques, like stress skins (eg. Yale triscuits) that work well, too.
There are other construction techniques, like stress skins (eg. Yale triscuits) that work well, too.
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