Failed Building Inspection on Set

I believe any sheet product that is rated for structural use like as sub floor will have the information printed on the sheet, including it's thickness and what the maximum span is.
 
Actually the construction industry goes on knowledge rather than labeling. They set up standards for lumber product that have to be strictly adhered to.
 
The labeling is also required. I'm also on a Contractor forum and this came up a few weeks ago. Specifically it was a discussion on some really cheap OSB somebody could get that was slightly smaller than full sheets(I think it was something like 7 1/2' x 4') and it was brand new still on the pallet. I the discussion decided it was trimmings from a OSB production run. Originally the discusion was about how it could be used to sheath a roof without cutting it down to 6'6" nd wasting 4 Sq.Ft.per sheet. Then it was brought up that these mill trimmings usually aren't stamped and therefore cannot be used for structural purposes. The mill overrubs are not uncommon, its just that the people at the mill usually buythem very cheap and they disappear, so the common person never sees it.

kicknargel, while I don't doubt there is OSB rated as subflooring over joists, and I've seem OSB panels with a membrane on the bottom designed as subflooring directly over concrete, I have never seen it done. All th subfloor I've ever seen are 3/4 CDX or rough cut 1x. I wouldn't trust any OSB less than 1 1/4" over joists as subflooring. As 3/4" CDX and 3/4" OSB weigh approximately the same(70-90Lbs) and a 1 1/4" OSB panel would weight 2/3 of that again, I can tell you my back would always choose the CDX although the cost in nominally higher. Also, the heavier panels would slow work and therefore make up the difference in cost. For wall sheathing, I have to go with Zip System(essentially an OSB panel with a vapor/moisture barrier built in) as it saves time and is weathers in the house that much faster. ZipSystem sheathing on a roof doesn't even need to be protected from the elements for a significant length of time, eliminating the rush to get the roof on.
 
Actually the construction industry goes on knowledge rather than labeling. They set up standards for lumber product that have to be strictly adhered to.

How do you think a building inspector can tell if the materials used are in fact what the building code requires?
 
Our dept. does NOT inspect engineering, just fire codes. However if we saw something questionable, we'd refer it to the building dept., it's THEIR job to determine if something meets building code or not.

That being said, I'd be careful as to whom you let build. 2x6 is the MINIMUM I'd use for a joist, and only for a 4' span at the most.
 
Our dept. does NOT inspect engineering, just fire codes. However if we saw something questionable, we'd refer it to the building dept., it's THEIR job to determine if something meets building code or not.

That being said, I'd be careful as to whom you let build. 2x6 is the MINIMUM I'd use for a joist, and only for a 4' span at the most.

So every 4x8 platform you build is 2x6 framed?
 
So every 4x8 platform you build is 2x6 framed?

Unless it's on casters, yes. 2x4's just don't have the strength for an 8' span. Even with 2x6's, I'd put in an midpoint support. The 2x6 also gives better support for sideways stresses. And you can use a 1/2" deck if it's good quality plywood on 12" centers. Always use quality lumber so you can reuse your platform, and build it right the first time. I'll run 2x lumber through a planer and sand it if it's going to show, nothing worse than a set looking like it was made out of somebodies half-***ed old deck.
 
Unless it's on casters, yes. 2x4's just don't have the strength for an 8' span. Even with 2x6's, I'd put in an midpoint support. The 2x6 also gives better support for sideways stresses. And you can use a 1/2" deck if it's good quality plywood on 12" centers. Always use quality lumber so you can reuse your platform, and build it right the first time. I'll run 2x lumber through a planer and sand it if it's going to show, nothing worse than a set looking like it was made out of somebodies half-***ed old deck.

A 2x6 framed 4x8 on 12" centers? I think my back is already sore.
 
A 2x6 framed 4x8 on 12" centers? I think my back is already sore.

Uh, you just have to work smart. I built a 27x36' shed all by myself, you just have to plan your moves. Put the framing in place before you put on the deck.
 
I've never had a problem with 2x4 and a couple of middle rails. And if you face it properly it not only won't look like a deck it will save all the time running it through a planer.


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Uh, you just have to work smart. I built a 27x36' shed all by myself, you just have to plan your moves. Put the framing in place before you put on the deck.

The point of 2'x4' platforms is to allow one to have an inventory of stock sized platforms that are easily moved and configured. Many us do not have a shop directly connected to our space, let alone the luxury of building entire sets directly in situ. Yes, for one specific production, we did build large platforms (I think they were 10'x10', might have been bigger) out of 2x8, with hanger straps, because the designer wanted 5 large platforms with open space beneath them, however this is more typically an exception than a norm.

A 4'x8' platformed, framed in 2"x6" on 12" centers, is incredibly over built and not standard for this industry.
 
The point of 2'x4' platforms is to allow one to have an inventory of stock sized platforms that are easily moved and configured. Many us do not have a shop directly connected to our space, let alone the luxury of building entire sets directly in situ. Yes, for one specific production, we did build large platforms (I think they were 10'x10', might have been bigger) out of 2x8, with hanger straps, because the designer wanted 5 large platforms with open space beneath them, however this is more typically an exception than a norm.

A 4'x8' platformed, framed in 2"x6" on 12" centers, is incredibly over built and not standard for this industry.

We don't have a shop at all, we try to do cutting outside as much as possible, and assembly on stage. A 2x6 frame is not overbuilt at all, the same size deck would be 2x8 minimum. And the 12" centers is only for 1/2" sheet, 5/8-3/4" would be 16" centers. I'd much rather slightly over engineer and need a couple of extra hands, than to have something fail. When you are working at height, your actors need to be confident that the set is not going to wobble or fall.
 
This is coming a little close to flame war for CB, where we like to be nice and civil. But there are time-tested industry standards that the professionals here and everywhere know and practice. And while we prefer over-built to under-built, the platforms as you describe are way over-built. 2x4 framing, with joists at 24" (or 16") centers, and legging on 4' centers is the industry standard. You might go heavier if you have a particular need (piano on platform, wider leg span, etc).

Build your platform as you wish--no concerns about safety (other than moving and lifting them). But for the posterity, it's overkill.
 
Not a flame war, merely an open avenue of informed debate, until someone makes it personal. But, since I have this milk jug of gasoline handy...

From Residential Wood Framed Floors (Residential Wood Framed Floors
and Aquarium Weights):
In the United States the minimum design floor live loads are usually stipulated in pounds per square foot (psf) by either state or local building codes. An example of typical design live loads might be 200 or 150 psf for a storage warehouse, 100 psf for a public meeting room, 50 psf for an office and 40 psf for a single family residence. So, your home most likely has the capacity to safely support a uniform live load of at least 40 psf. But keep in mind that this design live load is theoretically spread uniformly over the entire floor from wall to wall throughout your entire house. It is not a maximum load on any given area of the floor, it is just a theoretical average load that is used to design the floor for loads that are initially unknown. Some people find this confusing because in reality it is not the floor pressure (in psf) that matters at all, it is the floor load in pounds that really creates the stress in the primary structural framing members.
Must stage scenery construction "meet or exceed the most stringent requirements of applicable building codes" (IBC)? I don't know; I don't build or design scenery. But I DO KNOW that in the past I've built 2x4 framed, 3/4" plywood decked, 4x8 platforms, with
one toggle at 4'-0",
two toggles at 2'-8",
three toggles at 2'-0",
but never four toggles at 1'-7.2" or five toggles at 1'-4".

Which reminds me, I really should purchase that copy of Structural Design for the Stage that's been on my wishlist forever.
.
 
Portland Opera Association used to always have to put thier sets on a rake because of the nasty seating arrangement in the Keller Auditorium. To accomplish this rake they used individual platforms that were 6'x8' with a T&G framing arrangment on thier sides. The framing was 2"x6", 16"OC and was Luan Mahogany. These would sit on "Raker Blocks" and support the entire set which was typically rented or trucked in from the Warehouse. Now In that sense those decks < platforms> were not 'Over-built' they were supportting huge casts, massive amounts of scenery, and had to last for years. For the typical type show I work on now, in a LORT D or SPT3 type theatre, a 2x6 framed deck would probably be over-kill for just about any set that I can concieve of us building.
One thing we should all remember: speaking in absolutes in this business can get you in trouble very quickly.
In General terms framing with 2x6 in the Theatre is over building, but not always. A 2x4 will more than sufficiently span an 8' distance I know I've spanned 14' with 2x's It all depends on how many, and how they are screwed in the field.

3/4 CDX typically has a 60PSI bursting strength when supported on 16" centers.
CDX's biggest strength is in its resistence to lateral and torsional stresses which is why it's typically used as a sheeting material in "real" construction.

OSB even 3/4 IS an UNDERLAYMENT to be used being another covering it is not a finish layer to be trod on without more suipport or if it's a single layer.

How do I paint Plywood ? With a lot of paint. there is no great way to prep Ply that the grain wont show through except for lots of sanding and using a skim coat of Drywall compound or Bondo.


I once spent an entire month building Opera decks for Nike at Acme Scenic. My God that was a heavy, heavy, heavy job! But we trucked those decks all over the country, for years.
 
This is coming a little close to flame war for CB, where we like to be nice and civil. But there are time-tested industry standards that the professionals here and everywhere know and practice. And while we prefer over-built to under-built, the platforms as you describe are way over-built. 2x4 framing, with joists at 24" (or 16") centers, and legging on 4' centers is the industry standard. You might go heavier if you have a particular need (piano on platform, wider leg span, etc).

Build your platform as you wish--no concerns about safety (other than moving and lifting them). But for the posterity, it's overkill.

I use 2x6 for diagonal stresses. In terms of weight, you're only talking about 15 pounds, not a big deal. With 24" centers, you're just about locked into having 3/4" sheeting which is more spendy and heavier. Going one size up in a 2x is nowhere near "way over-built". Somebody else's kids are on that platform that I'm building, follow me?
 
Portland Opera Association used to always have to put thier sets on a rake because of the nasty seating arrangement in the Keller Auditorium. To accomplish this rake they used individual platforms that were 6'x8' with a T&G framing arrangment on thier sides. The framing was 2"x6", 16"OC and was Luan Mahogany. These would sit on "Raker Blocks" and support the entire set which was typically rented or trucked in from the Warehouse. Now In that sense those decks < platforms> were not 'Over-built' they were supportting huge casts, massive amounts of scenery, and had to last for years. For the typical type show I work on now, in a LORT D or SPT3 type theatre, a 2x6 framed deck would probably be over-kill for just about any set that I can concieve of us building.
One thing we should all remember: speaking in absolutes in this business can get you in trouble very quickly.
In General terms framing with 2x6 in the Theatre is over building, but not always. A 2x4 will more than sufficiently span an 8' distance I know I've spanned 14' with 2x's It all depends on how many, and how they are screwed in the field.

3/4 CDX typically has a 60PSI bursting strength when supported on 16" centers.
CDX's biggest strength is in its resistence to lateral and torsional stresses which is why it's typically used as a sheeting material in "real" construction.

OSB even 3/4 IS an UNDERLAYMENT to be used being another covering it is not a finish layer to be trod on without more suipport or if it's a single layer.

How do I paint Plywood ? With a lot of paint. there is no great way to prep Ply that the grain wont show through except for lots of sanding and using a skim coat of Drywall compound or Bondo.


I once spent an entire month building Opera decks for Nike at Acme Scenic. My God that was a heavy, heavy, heavy job! But we trucked those decks all over the country, for years.

I absolutely hate CDX and OSB unless they are for underlayment. Way too much chipping and splinters. You can however skim coat it with drywall mud if it's not a walked on surface or moved much.
 
The combo of 2x6 AND 12" centers I think is what he meant. With only $5-10 difference in price between 1/2 and 3/4 wouldn't the buying of a couple more 2x6s for the added toggles balance out in the long run?


Via tapatalk
 
The combo of 2x6 AND 12" centers I think is what he meant. With only $5-10 difference in price between 1/2 and 3/4 wouldn't the buying of a couple more 2x6s for the added toggles balance out in the long run?


Via tapatalk

The 12" centers would only be for 1/2" material, some of it like OSB won't last long, especially with a big or multiple actors. It's easier to throw some 2x's in a vehicle than a 4x8 sheet. I can get a few 2x's inside my 4dr Jeep, and I can get 10' 2x's in the van, but not a 4x8 sheet. That lets me reuse some of the old sheet goods.
 

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