Legging Tall Platforms

New Kid

New Member
]I was wonder how you would leg a 10ft platform. I was thinking about either using 2 2x4 per coner and 2 in the Center. Or using a stud frame method of legging. I have done this with smaller platforms but never any 10ft in the air. Here is an image of how I am thinking about forming the stud legging sections.
image.jpg
 

TheaterEd

Renaissance Man
Fight Leukemia
Keep in mind that 2x4s are 1.5" thick. It's 24" centers, not 24" between each one. Make sure you cross brace everything, and the stud wall method is the way to go.
 

BSchend

Member
Standard building construction is 16" on center (so that the center of a 2x4 lands every 48" for drywall). 24" on center is probably strong enough. If no center supports (i.e. only a stud wall down both 8' lengths) the weak point isn't the stud wall it's the span of the platform. The other weak point will also be the attachment of the stud wall to the platform unless you are cross bracing across the 4 foot span. If you do that you might as well do 3 4x10 stud walls instead of 2 8x10. It's actually less material.
 

BillConnerFASTC

Well-Known Member
How big is the platform? The design load per column - really what a leg is - along with material determines the column size so it won't buckle under the load; and the total load determines lateral bracing requirements so it doesn't parallelogram. Of course the construction of the platform plays into this. If you'd support the platform 1' high at just the 4 corners, no reason not to support it on four legs at 10' high, just the legs will be different probably.
 

New Kid

New Member
Thank you for all the replies and help. Nothing is set in stone yet but I am looking to do a 24'x8' platform. I was thinking doing stud walls for legging running them at 8 feet long and having 9 of them across the front using 4x8 platforms and having the 8 foot long sections parallel to the edge of the stage. This means the 8 foot stud walls would actually be running from upstage to downstage under 2 different platforms. Then I would cross brace from wall to wall and brace the sides of each individual stud wall
 

BillConnerFASTC

Well-Known Member
I think you could do this a little simpler with 2 24' stud walls, a diagonal at each end of each walk, and Xs us-ds at ends and center. Just as a concept. That's 48' plus 2 extra studs versus 72' plus plus 9. But you need to consider all details, like nailing, the platforms, etc. For instance, studs toe nailed to plates, not end nailed through plates.

And then I wonder why not 3 - 8' walls and 2 x 10 or 12 joists left to right. Building it all of individually dreamed 4x8s is not efficient IMHO. And today I'd look at i-joists, since one person can pick it up versus 2 for 2 x 12 of same length.
 

New Kid

New Member
This platform won't be moving and will be toenailed into the stage. If I do 2 24' studs from stage left to right then would I support the middle with a 3rd. Or would I use joist to go from up stage to downstage across the studs then place the platforms. The platforms are standard platforms from 2x4 and 3/4 in ply. I know they can support weight without a center brace in theory but the director and myself would feel a lot better overbuilding and being a little impractical if it means less doubt in the mind.
 

BillConnerFASTC

Well-Known Member
This platform won't be moving and will be toenailed into the stage. If I do 2 24' studs from stage left to right then would I support the middle with a 3rd. Or would I use joist to go from up stage to downstage across the studs then place the platforms. The platforms are standard platforms from 2x4 and 3/4 in ply. I know they can support weight without a center brace in theory but the director and myself would feel a lot better overbuilding and being a little impractical if it means less doubt in the mind.

I think what you proposed is fine if not overkill. But a single diagonal from each corner in each direction - that would be 8 - plus an "X" at one or two lines in center (at center or at 8 and 16' from one end) would be ample. I do caution you about nailing patterns and sizes. Sheathing some of the stud walls with ply is better than diagonal braces - but again nailing patterns are specific.

Once did a 24' long deck - only 3' wide - supported at the ends - using stressed skin platforms - and only 4" thick. Very cool.
 

New Kid

New Member
I think what you proposed is fine if not overkill. But a single diagonal from each corner in each direction - that would be 8 - plus an "X" at one or two lines in center (at center or at 8 and 16' from one end) would be ample. I do caution you about nailing patterns and sizes. Sheathing some of the stud walls with ply is better than diagonal braces - but again nailing patterns are specific.

Once did a 24' long deck - only 3' wide - supported at the ends - using stressed skin platforms - and only 4" thick. Very cool.

What is you suggested nailing patterns and sizes?
 
Personally i would say use 4x4's for all the legs because it'll make it more stable, it may cost more but not as much as a medical bill. oh and use 2x4's for cross bracing, you may have already of know that but it wasn't show on the plan.
 

TheaterEd

Renaissance Man
Fight Leukemia
Personally i would say use 4x4's for all the legs because it'll make it more stable, it may cost more but not as much as a medical bill. oh and use 2x4's for cross bracing, you may have already of know that but it wasn't show on the plan.
If you are doing a full stud wall 4x4 is WAY overkill.
 

New Kid

New Member
Yes. Thank you for you help. I could always put 4x4 in the comers of the platforms and call it a day. If I was to build stud walls with 4x4, I might as well put a big wooden block underneath.
 

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