Temporary stage plans

[swindmill]

I'm building this 8'x15' stage for a fundraising event. The plans I've attached were drawn up by an architect. They are obviously pretty simple, but I have a couple questions (the person who drew them up isn't available).

A 2x8 will be anchored to the porch, so that the stage will be an extension of the porch, much like you'd build a deck. We'd like to use concrete anchors that we can leave in place as this will go up every year. Is there a specific type or size of anchor that anyone would recommend?

Second, at 15', I'm assuming we'd use two 2x8x8s against the porch, and at the front. I'm not sure if the blue box store nearby would carry a 2x8x16.

There's no mention of joist hangers, but I plan to use them along the back. At the front, I'll attach three of the 2x8x8s to 4x4s sitting on the concrete foot forms, and I suppose use joist hangers for the other two.

The last question I have at the moment is about the 'bolt panels'. I honestly just don't know what that is referring to. A substitute for screwing down the sheets of plywood on top is my best guess.

I've never built off of plans like this, so I may just be unfamiliar with what I'm looking at. Thanks for any clarifications and information.

 

[Snoonyb]

What is the anticipated occupancy of this stage?

 

[swindmill]

2-3 people and some audio equipment.

 

[Snoonyb]

Thanks.

I would do this slightly differently. I'd set 1-14" threaded dowels into the existing porch. then install a treated 3x6, (which could remain) and hang 4x6 treated girders at 4'OC off the 3x6 with Simpson Strong Tie HUTF and HUC's and supported by the piers, mentioned, under each and a 2x6 rim joist, then use treated 2-4-1 plywood.

Because you intend to assemble and disassemble, use screws instead of nails.

 

[joecaption]

#1 it should be 8 X 16 not 15 if possable, less waste and cutting time.
Any real lumber yard will have 16' lumber.
Would be interesting to know why he suggested using pressure treated joist and plywood, if it's temporary it's not needed.
Pressure treated plywood is full of voids and has a habit of delaminating, I'd use Advantech instead.
Guessing your going to have to disassemble this and store it until the next event.
If that's the case I'd suggest building the joist system as two seperate units that can bolt together in the middle.
That way once the subfloor is removed you would have 2, 8 X 8 sections of framing two people can handle easily.
To attach the subflooring all you need is 4 decking screws, one in each corner, it's not going anywhere.

 

[nealtw]

I do not understand the plywood panels, A joist every 4 feet with plywood going the wrong way and only screwed on the edges.

 

[Snoonyb]

Who said that?

 

[joecaption]

Not me, I never suggested getting rid of any joist, in fact with my suggestion there would be what would amount to a double beam in the center where the two seperate decking frames bolt together.

 

[Snoonyb]

I said 4x6 @ 4'oc, and you said a screw in each corner, so maybe, it's a blanket endorsement?

 

[swindmill]

I'm not sure why he suggested treated. It will be in place for a few days each year, so it may not be necessary. I will suggest a different plywood, at the very least. As far as the structure, I can probably suggest a few sensible changes, but my feeling is that they will want to leave it similar to the plans they have. I do think making it 8x16 rather than 15 makes perfect sense, if the space allows, and I believe it does. I will also suggest two 8x8 sections for simplicity. The owner of the property won't want anything left attached to the porch, aside from the anchors. My main question at this point is what type and size of anchors to use.

 

[nealtw]

This what I have seen as stage panels. 2 pieces of paper faced plywood with a frame work between, same as door construction.

 

[nealtw]

He went 15 ft to leave the stairs usable.
You want flush mount achors so you don't have bolts sticking out in a stair case.
http://www.drillcodevices.com/maxi_bolts/general/flush.html

 

[Snoonyb]

So to simplify, the platform is 3-4x8 panels and 1-3x8 panel bolted together.

I would use 2 anchors per panel, within 8" of the end of each, where they attach to the concrete.

 

[swindmill]

So to simplify, the platform is 3-4x8 panels and 1-3x8 panel bolted together.

I would use 2 anchors per panel, within 8" of the end of each, where they attach to the concrete.

Are you suggesting that I make 4 separate structures and then bolt them together to make 1? I was thinking 2 structures (8x8 & 8x7). With 4, they might be able to store them without disassembling, so that may work. It'll take a few more 2x8s.

 

[swindmill]

I got RedHead drop in anchors for the porch. I've never used this type, but it seems like the best female flush mount solution. I got a bunch of carriage bolts to put the sections together. We'll see how this goes...

 

[Snoonyb]

Are you suggesting that I make 4 separate structures and then bolt them together to make 1? I was thinking 2 structures (8x8 & 8x7). With 4, they might be able to store them without disassembling, so that may work. It'll take a few more 2x8s.

Yes, because they are much less cumbersome, and unless you want to crawl underneath, you need to remove the 3/4" floor sheating to disassemble.

 

[swindmill]

I am following the advice to make 4 panels. Can I put just one joist in the middle of each panel? That would about 22" on center in each 4' wide panel. I'm trying to cut down on price and weight where I can.

 

[Snoonyb]

That would be pushing the envelope of the stability of the 3/4" plywood, as well as the cost alternatives, IE. struc 1 or marine grade, unless they are not concerned with a little bouncing.

 

[nealtw]

I think this is nuts. It looks like a set of plans that was drawn by some one with limited knowledge on the subject with a limit to what it will be used for but removable for future unknown use.
There are engineers in this business and they carry the insurance for when designs fail.
Google deck or stage collapse