# Platform Safety



## BLengyel (Feb 11, 2012)

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.


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## Brian553 (Feb 11, 2012)

BLengyel said:


> I figured I would build it from four 4'x8' and two 2'x8' platforms build from 3/4 plywood and 1x6.


 
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!!!


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## MNicolai (Feb 11, 2012)

Brian553 said:


> 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.


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## BLengyel (Feb 11, 2012)

Brian553 said:


> 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!!!


 
yes I mean 2x6


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## BLengyel (Feb 11, 2012)

I was assuming that if I build this out of mutliple platforms it will distribute the weight a bit more. evenly. and take alot of pressure. And I may help to put 2 toggles in each platform.


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## derekleffew (Feb 11, 2012)

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.


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## BLengyel (Feb 11, 2012)

derekleffew said:


> 1. Use 2x4 instead of 1x6.
> 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, 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.


 
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.


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## BLengyel (Feb 12, 2012)

derekleffew said:


> 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.


 
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.


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## Tex (Feb 12, 2012)

BLengyel said:


> 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.


If you're building and bracing your compression legs properly, it's not that much more expensive or time-consuming to build knee walls. They're also safer, faster to install and generally easier to deal with, IMO.
For a platform unit this large with a heavy load, build the knee walls.


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## BLengyel (Feb 12, 2012)

Tex said:


> If you're building and bracing your compression legs properly, it's not that much more expensive or time-consuming to build knee walls. They're also safer, faster to install and generally easier to deal with, IMO.
> For a platform unit this large with a heavy load, build the knee walls.


 
Okay, thanks I will definitely do so.


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## BLengyel (Feb 12, 2012)

Tex said:


> If you're building and bracing your compression legs properly, it's not that much more expensive or time-consuming to build knee walls. They're also safer, faster to install and generally easier to deal with, IMO.
> For a platform unit this large with a heavy load, build the knee walls.


 Actually I have another question, do You think that I could use luan keystones for bracing the knee wall system for sake of cutting back on the amount of luan we need to buy.


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## JLNorthGA (Feb 12, 2012)

BLengyel said:


> Actually I have another question, do You think that I could use luan keystones for bracing the knee wall system for sake of cutting back on the amount of luan we need to buy.


 
You really should use something a bit thicker than thin lauan. I would go for at least 3/8" plywood for the keystones. You can often find offcuts in the scrap bins at Home Depot and Lowes.


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## BLengyel (Feb 12, 2012)

JLNorthGA said:


> You really should use something a bit thicker than thin lauan. I would go for at least 3/8" plywood for the keystones. You can often find offcuts in the scrap bins at Home Depot and Lowes.



I was just going by derekleffew's My Platform Systme's instructions in my plan for the pit.


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## josh88 (Feb 13, 2012)

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.


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## Van (Feb 13, 2012)

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.


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## BLengyel (Feb 13, 2012)

Van said:


> 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.



Yeah the thing is with our stock platforms being build with 1x6 I wasn't sure if it would get the job done. But I'm definitely planning on re framing some of these platforms with 2x4's.


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## kicknargel (Feb 14, 2012)

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.


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## BLengyel (Feb 17, 2012)

kicknargel said:


> 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?


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## josh88 (Feb 17, 2012)

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


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## sk8rsdad (Feb 17, 2012)

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.


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## Van (Feb 17, 2012)

josh88 said:


> 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



Yes, Josh, it's extremely common. If you were to build a set with 4x8 platforms framed with 2x in this town people would probably be wondering what planet you come from. A lot has to do with how you leg, what the intended purpose is and what the load is going to be. Would I frame a piano riser with 1x ? no, Of course not, unless it is a 5" rise and the plat is sitting directly on the deck. But by the time you 'properly leg a 2x framed platform, you might as well have framed with 1x. a 4' span of 1x4 covered with 3/4" properly nailed and glued is more that sufficient for carrying typical stage traffic. 
I don't know what 1x6 or 1x4 framed platforms you may have looked at but believe me I quit framing with 2x4 about 20 years ago.


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## BLengyel (Feb 17, 2012)

Van said:


> Yes, Josh, it's extremely common. If you were to build a set with 4x8 platforms framed with 2x in this town people would probably be wondering what planet you come from. A lot has to do with how you leg, what the intended purpose is and what the load is going to be. Would I frame a piano riser with 1x ? no, Of course not, unless it is a 5" rise and the plat is sitting directly on the deck. But by the time you 'properly leg a 2x framed platform, you might as well have framed with 1x. a 4' span of 1x4 covered with 3/4" properly nailed and glued is more that sufficient for carrying typical stage traffic.
> I don't know what 1x6 or 1x4 framed platforms you may have looked at but believe me I quit framing with 2x4 about 20 years ago.



I have 2 2x8 platforms and 4 4x8 platforms built from 3/4" ply and framed with 1x6. I plan on legging these all together to form the pit platform . it has to hold the weight of 2 guitar players, 1 bass player, 1 keyboard, 1 drumset, 1 sax, 2 clarinets, 2 violinist's, and 1 trumpet. I didn't officially find out the count of the pit until today. So no one is really running around on them basically it just has to hold all these people plus equipment.


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## Van (Feb 17, 2012)

BLengyel said:


> I have 2 2x8 platforms and 4 4x8 platforms built from 3/4" ply and framed with 1x6. I plan on legging these all together to form the pit platform . it has to hold the weight of 2 guitar players, 1 bass player, 1 keyboard, 1 drumset, 1 sax, 2 clarinets, 2 violinist's, and 1 trumpet. I didn't officially find out the count of the pit until today. So no one is really running around on them basically it just has to hold all these people plus equipment.



If you leg each corner an the middle of each span you should be able to carry that liitle weight easily. The important thing being that the framing is good < not full of knot holes> and that the coer is sufficiently bonded to the framing < Lots of staples/screws and a still-good coat of glue. If the glue has dried and cracked and the tops are loose at all then you should strip and recover or rebuild.> Remember that the big thing with the legging is that you want to either use a larger enough leg that is can't bend under load or make sure that it is sufficiently cross braced so it can't bend.


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## BLengyel (Feb 17, 2012)

Van said:


> If you leg each corner an the middle of each span you should be able to carry that liitle weight easily. The important thing being that the framing is good < not full of knot holes> and that the coer is sufficiently bonded to the framing < Lots of staples/screws and a still-good coat of glue. If the glue has dried and cracked and the tops are loose at all then you should strip and recover or rebuild.> Remember that the big thing with the legging is that you want to either use a larger enough leg that is can't bend under load or make sure that it is sufficiently cross braced so it can't bend.



I suppose that would be fine then, would you recommend compression legs. I know we have a ton of compression legs on stock from last years show but I suppose we could build a knee wall legging system instead of compression legs. I feel that the might take the load a lot better then the compression legs made from 2x4 and 1x4. I'm kind of freakin out because If I mess this up then we are in big trouble, because we're crunched for building time as it is and have a very small margin of time to do this. So basically it has to be reliable the first time.


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## Van (Feb 17, 2012)

As long as the platforms and the legs are in good shape this shouldn't be a problem. 2x4 comp legs work great with 1x4 framing as the 2x material will support 2 platforms at once. Of course you still want the plat forms botled together to help give each other strength..


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## josh88 (Feb 17, 2012)

huh, well then,



granted the times I saw them were in storage in a venue that probably had someone who had heard to build them with 1x but probably didn't know what they were doing, so they were shoddily made and with 1/2 on top I think. I guess I hadn't thought about it honestly, my students have such a tendency to split 2x4's even after pre drilling things, that they would destroy 1x4's in a heartbeat. That sure would cut down on the weight, I may have to read up some more.


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## BLengyel (Feb 17, 2012)

Yes, I'm very curious about this. The varying information makes me worry about taking the risk. I guess it all really comes down to the quality of the build, bracing and legging.


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## BLengyel (Feb 17, 2012)

So what I think I'm going to go with is 4 4x8 platforms framed in 1x6 with 8-9 compression legs per platform. so basically a leg ever 4 feet, and then brace it with 1x4's and toe rail. Then Bolt all of the platforms together and secure them to the floor with angle irons. I'm a bit skeptical but I feel fairly confident that this should work out. I hope.


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## BLengyel (Feb 18, 2012)

How much would someone estimate that a 4x8 platform framed in 1x6 properly with 3 toggle rails and a 3/4 inch lid 9, 9 compression legs (1 for each toggle, each corner and in the middle of the 8 foot sections of the frame), all braced with 1x4's diagonals and toe rails, with each platform bolted together by the frame then secured to the stage with plenty of angle irons. Would you believe this could hold upwards around 2000lbs distributed. (as an estimate) around 1500-1600 is a closer estimate based on the people that are in the pit with the weight of amps, keyboard, and drum-set figured in.


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## kicknargel (Feb 18, 2012)

I don't know that you're going to get anyone to give you an engineer's stamp of approval on an internet forum, but the system you describe falls within industry standard practice for basic platforming.


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## Les (Feb 18, 2012)

BLengyel said:


> How much would someone estimate that a 4x8 platform... ...Would you believe this could hold upwards around 2000lbs distributed. (as an estimate) around 1500-1600 is a closer estimate based on the people that are in the pit with the weight of amps, keyboard, and drum-set figured in.



How are you going to get all that on a 4x8 platform? 

I realize that you're actually going to be using a system of platforms. One note - don't underestimate the weight of the keyboard rig. Looks like it will be fine, but estimate that the keyboard and and amp will weigh about 200 pounds if they're using an 88-key weighted board. They're darn heavy! They also take a lot of space, so make sure that the measurements you have taken include the player in a comfortable position. Nothing is worse for a keyboard/piano player than having to sit too close to their board.


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## BLengyel (Feb 18, 2012)

Les said:


> How are you going to get all that on a 4x8 platform?
> 
> I realize that you're actually going to be using a system of platforms. One note - don't underestimate the weight of the keyboard rig. Looks like it will be fine, but estimate that the keyboard and and amp will weigh about 200 pounds if they're using an 88-key weighted board. They're darn heavy! They also take a lot of space, so make sure that the measurements you have taken include the player in a comfortable position. Nothing if worse for a keyboard/piano player than having to sit too close to their board.



haha yeah I just realized that. I do believe it is an 88 weighted board. But I figured in 3 amps at around 50 pounds each and about 100 pounds for the keyboard.


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## Les (Feb 18, 2012)

BLengyel said:


> haha yeah I just realized that. I do believe it is an 88 weighted board. But I figured in 3 amps at around 50 pounds each and about 100 pounds for the keyboard.



That sounds about right!


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## chausman (Feb 18, 2012)

Don't forget to make sure they are level, especially between platforms. If not, your drummer may want to kill you later. 


Sent from my iPhone using Tapatalk


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## BLengyel (Feb 18, 2012)

chausman said:


> Don't forget to make sure they are level, especially between platforms. If not, your drummer may want to kill you later.
> 
> 
> Sent from my iPhone using Tapatalk



Oh believe me I know, I went through hell last year trying to get our once upon a mattress set level. those platforms just wouldn't stay flush. Our stage just isn't the greatest so It's not level in many place so we may require some shims for this mass of platforms.


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