Plywood for Decking

[Dustincoc]

I'm constructing a deck in place framed with 2x4's on 18" centers. Do I realy need 3/4? plywood for the top or would 1/2" be good. I've got a few sheets of 1/2" in the shop and no 3/4" and the budget is really tight on this show so I don't know if I can afford to skin the deck in 3/4".

[Van]

How big of a deck, what's the final load going to be on it? how long will it be in service? is you don't know the exact load, how many people are going to be standing on it ? Dancing ? milling around ?

[Dustincoc]

Originally Posted by Van

How big of a deck, what's the final load going to be on it? how long will it be in service? is you don't know the exact load, how many people are going to be standing on it ? Dancing ? milling around ?

lower level is 6" high and 3-5' deep. Upper level is around 5-8 feet deep. Both decks run the entire width of the stage which is about 16 feet.The show is running for 6 weeks with 5 actors who will be dancing, ect.

[Van]

I would go with no less that 3/4" cdx with a Masonite top, or 5/8" OSB if you can find the T&G osb it's better for dancing.

[curtg]

I concur with Van. 3/4 is minimal even with your solid framing.

Will you reuse this platform. If so, make the argument that the platforms will be going into stock. Sometimes there is a budget for necessary stock items.

[DaveySimps]

I agree with both previous posts. For me, I never use less than 3/4" ply on platforms with 1/4" masonite top. It is abaolutely worth the extra $$$.

~Dave

[Marius]

If your superiors give you flack about the extra cost use the magic word 'liability' should one of the dancers go through the deck. I tried using 1/2 ply for a 4'X4' that would only be walked on, and then practically developed an ulcer as I watched it flex every time it was stepped on. Never again.

[jwl868]

Although my experience is much less than the previous posters, stick with the ¾-inch plywood. We have a few 4x4 platforms with ¾-inch decks, and for a recent recital, we had to use an extra older 4x4 platform that had a 1/2-inch deck. It had way too much flex but only needed to be walked on. We reinforced it from below with more 2x4s. (Luckily, it only needed to be stepped on by one dancer, not danced on.)


Joe

[gafftaper]

There is a school of thought out there that says you can use thinner woods... I believe "The Stock Scenery Construction Handbook" is in favor of thinner stock if I remember right. Some people use 5/8" or even 1/2". Unless it gets really abused, you have a lot of actors, or heavy actors on the platform the thinner woods will not break... do the math about the load, don't just guess. However, I have not been impressed with the results I have seen. Thinner wood flexes and that means, a stage that is moving which means more noise, and a hollow sound. It can be done if you need to for a traveling show but it's not a result you are going to be happy with for the most part (again do the math).

[David Ashton]

If you have stock of 1/2" then simply double up, it will be stronger than 3/4, it is a waste of money in the long term but solves the short term problem.