# Plywood floors a mess in 5 yr old theater, they are glued down??



## AviatorDrama (Dec 27, 2015)

Ok, I know this subject has been beat to death, I've read every thread I can find but no one seems to have my same issue.

In a nutshell:
Gorgeous new middle school theater, amazing lighting/sound equipment that no one knows how to use. Contractor who built the school had no specs or knowledge of theaters. There are more oddities than I can count. He can't be found anyway (though it's a very small town??) 

The stage floor is approx. 80' x 30' of rough tongue and groove plywood. Half of the brass outlets in the floor don't have electricity run to them, just empty holes. It has bubbles in many, many places from water damage and being painted (twice in 5 years) and these bubbles are starting to break off, leaving pits and jagged edges, gaff tape pulls them off. We were going to replace the worst of the plywood sheets, only to find that they had all been glued down. We can't cover it with another material because it would change the height (it butts up to the edge of the auditorium carpet and school hallway tile)

We **may** be getting an addition built on to the school in this wing next summer, so I'd like to suggest something be done to help the situation and give our stage more longevity.

Thought? Ideas?


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## lwinters630 (Dec 28, 2015)

AviatorDrama said:


> Ok, I know this subject has been beat to death, I've read every thread I can find but no one seems to have my same issue.
> 
> In a nutshell:
> Gorgeous new middle school theater, amazing lighting/sound equipment that no one knows how to use. Contractor who built the school had no specs or knowledge of theaters. There are more oddities than I can count. He can't be found anyway (though it's a very small town??)
> ...


It sounds like the plywood is glued to concrete. This is not the correct setup. It should have had a vapor barrier, 2x4 sleepers flat and anchored, plywood glued and screwed to sleepers, then a finished product like: hardwood, masonite, MDF, to name a few.
T & G plywood is not solid core, it will have voids inside ply layers, which is why it is falling apart and not approved as a final floor. No wonder you can't find the contractor. Plus you don't need him as he doesn't know how to put i, a proper floor.

Your best solution is to sand loose/broken spots. Secure the plywood with tapcons, 6" on perimeter and 16" in field. Then patch with Ardex fether finish or Mapei plani-patch. Should be flat within 3/16 over a 10' span.
Next choose a finish product like 1/4" masonite or MDF. Paint all 6 sides with rosco tough prime or PPG waterborne wrought iron. . Offset seams, space sheets (thickness of dime). Countersink screws. Final coat of paint.
Hold edge back from hall and use Johnsonite CTA-XX-H rubber reducer 1/4 to 1/8 for vct or carpet. Or similar depending on your needs. These transitions are used in hospitals and will meet your codes for access.
I would also replace the brass electric rings with stage floor boxes as they don't stick up.
If you are looking for a flooring contractor look up well established local owned flooring stores. Not big box.
I truly hope this will get you in the correct direction.


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## AviatorDrama (Dec 28, 2015)

lwinters630 said:


> It sounds like the plywood is glued to concrete. This is not the correct setup. It should have had a vapor barrier, 2x4 sleepers flat and anchored, plywood glued and screwed to sleepers, then a finished product like: hardwood, masonite, MDF, to name a few.
> T & G plywood is not solid core, it will have voids inside ply layers, which is why it is falling apart and not approved as a final floor. No wonder you can't find the contractor. Plus you don't need him as he doesn't know how to put i, a proper floor.
> 
> Your best solution is to sand loose/broken spots. Secure the plywood with tapcons, 6" on perimeter and 16" in field. Then patch with Ardex fether finish or Mapei plani-patch. Should be flat within 3/16 over a 10' span.
> ...



This is quite a detailed and thorough solution. However, the stage floor is not on concrete. It is 32" off of the auditorium floor. As I understand from the maintenance man who tried to pry up a panel: the tongue and groove edges are glued together, as well as, to the sub-floor....and possibly the sub-floor is glued to the floor joists, rather than screwed or nailed....he was afraid to pry up more than a small area because the plywood was splintering. 

I like your idea of repairing the spots, but there are dozens and dozens of them, large and small.
I've added your suggestions to the proposal. We have two reputable flooring companies in our town...but they are mom & pop shops, so I wonder if the district would risk making the problem worse. Maybe we should consult a flooring specialist in a large city (Nashville)?

Another question:
What would be the downside to ripping the entire stage floor up and laying it properly to last for decades....besides the horrid cost, of course. And the fact that we have rentals booked up every weekend this summer at $1k per day....we can't afford to have a mess for months.


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## BillConnerFASTC (Dec 28, 2015)

If ply is glued to subfloor, I think your best solution is indeed to tear up subfloor as well, and replace both layers. Better would be to rebuild with a resilient floor, but that involves reframing and probably a lot of other redos. I don't know thicknesses or spans and wonder if it was built to code for strength but ply subfloor as thick as will fit - I usually specify 1 1\8" - and 3/4" plyron screwed down and painted would serve well I believe. Your mention of humidity makes hardboard a particularly less good solution.


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## robartsd (Dec 28, 2015)

Since this is not ply on concrete, it sounds like the moisture problem is from painting - shouldn't priming all sides before install mitigate moisture problems from painting. If there are other moisture issues, they may need addressing as well.


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## BillConnerFASTC (Dec 28, 2015)

Most of the southeast is simply humid for a large part of the year. The seasonal variations are significant. In addition, rather than just going deeper ion debt, they tend to set back or shut off ac - humidification - often; and you can count on it when the next energy crisis hits - as it will inevitably. Plyron is simply much more dimensionally stable than hardboard mechanically fastened to ply, and quieter as well. They fact that there are many fewer fasteners is only a bonus. Its an option and everyone is free to select which is better for them.


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## lwinters630 (Dec 28, 2015)

AviatorDrama said:


> This is quite a detailed and thorough solution. However, the stage floor is not on concrete. It is 32" off of the auditorium floor. As I understand from the maintenance man who tried to pry up a panel: the tongue and groove edges are glued together, as well as, to the sub-floor....and possibly the sub-floor is glued to the floor joists, rather than screwed or nailed....he was afraid to pry up more than a small area because the plywood was splintering.
> 
> I like your idea of repairing the spots, but there are dozens and dozens of them, large and small.
> I've added your suggestions to the proposal. We have two reputable flooring companies in our town...but they are mom & pop shops, so I wonder if the district would risk making the problem worse. Maybe we should consult a flooring specialist in a large city (Nashville)?
> ...


I have over 30 years of flooring experience so let me see if we can solve this. The fact that you are not over concrete is better. Ignore the tapcons but do secure the ply wood to the floor joist. This is how a standard 3/4 plywood deck is installed. Glued and nailed. The "water damage" is likely just that the plywood is not a solid core and must have a finished product over it. You cannot use a resilient (like vinyl) without using a solid core underlayment like 1/4 multiply glued and stapled, follow mfg instructions. Structurally you are fine and will not gain anything from tearing it out. Prep will be as I described. 

Next question is what type of finished floor do you need. What do you do on the stage? If you want plain black then the masonite or MDF will work directly over the prepared plywood. If your rentals are mostly dance then Rosco dance floor can be used over the multi-ply. 

Estimates:
Re nail 3/4 tag ply .25 sf
Prep floor .45 sf
Multi ply 1.75sf installed
Rosco dance type floors. $4 to 7 installed.
Johnsonite transitions apx. $2.25 LF.
This should get you close.
If mom and pop have been around for 10 years I'd have them out to look at it. Show them my notes.
Anything more and I'd need pictures or PM me.


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## lwinters630 (Dec 28, 2015)

Bill mentioned Plyron. Excellent product. Secure and prep the plywood before putting down Plyron.


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## AviatorDrama (Dec 29, 2015)

lwinters630 said:


> I have over 30 years of flooring experience so let me see if we can solve this. The fact that you are not over concrete is better. Ignore the tapcons but do secure the ply wood to the floor joist. This is how a standard 3/4 plywood deck is installed. Glued and nailed. The "water damage" is likely just that the plywood is not a solid core and must have a finished product over it. You cannot use a resilient (like vinyl) without using a solid core underlayment like 1/4 multiply glued and stapled, follow mfg instructions. Structurally you are fine and will not gain anything from tearing it out. Prep will be as I described.
> 
> Next question is what type of finished floor do you need. What do you do on the stage? If you want plain black then the masonite or MDF will work directly over the prepared plywood. If your rentals are mostly dance then Rosco dance floor can be used over the multi-ply.
> 
> ...




Ok, great, this sounds like a doable plan. I've tried to educate myself on the products you've listed and added all of these suggestions to the proposal. I think Plyron is quite a bit out of our price range, so Masonite will need to suffice. I'll call the local mom and pop, 40 yrs exp, to get an estimate based around your ideas. 

Our stage is primarily used for middle school plays, musicals and band concerts, plus at least 7 weekends per year it is rented by local dance studios for their recitals. I don't suppose sprung dance flooring is warranted, nor would the district likely pay for it.

We don't have a scene shop (one of the things I'm asking for if they add on to the building) so we build scenery on the stage floor. I try to protect it as much as possible. Plus the cheap plastic casters used in the past have made deep grooves in the surface. I only use rubber wheeled casters. 

I plan on taking some close up photos this week to show you the damage. Until then, I have one question about preparing the existing plywood. Should the screws be removed and holes filled before prepping for the Masonite?

Thank you very very much for this advice. I need all the help I can get.


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## SteveB (Dec 29, 2015)

Big question is are you adding height ?.

If so, you will need to plan ramps and such at room entry points. Especially a need to plan a robust ramp for loading door points where heavy stuff gets rolled.


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## BillConnerFASTC (Dec 29, 2015)

AviatorDrama said:


> I think Plyron is quite a bit out of our price range, so Masonite will need to suffice.



Do consider that plyron replaces both the hardboard and a layer of ply, including installation labor; fasteners can be on 2' centers with plyron versus 16 (or less on hardboard) tines two layers; and the hardboard needs to be painted - probably two coats - all surfaces before installing. Just look at time and all of the materials before being sure plyron is not more economical than plywood (underlayment) plus hardboard.


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## lwinters630 (Dec 30, 2015)

AviatorDrama said:


> Ok, great, this sounds like a doable plan. I've tried to educate myself on the products you've listed and added all of these suggestions to the proposal. I think Plyron is quite a bit out of our price range, so Masonite will need to suffice. I'll call the local mom and pop, 40 yrs exp, to get an estimate based around your ideas.
> 
> Our stage is primarily used for middle school plays, musicals and band concerts, plus at least 7 weekends per year it is rented by local dance studios for their recitals. I don't suppose sprung dance flooring is warranted, nor would the district likely pay for it.
> 
> ...


Those hard cheep wheels do a lot of damage. Look for the rubber with flat tread vs hard and crowned. You do not have to remove screws or nail from the plywood. Do make sure it is secured, then prep. As for protecting the stage floor for set builds, We found a billboard company that donated large 22'x60' heavy vinyl billboard signs that are supper durable. Post pictures, include door transitions, transitions to carpet, walls, anything. Ill try to suggest transitions for you.

Bill has good points on the Plyron. It may require less prep.


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## lwinters630 (Dec 30, 2015)

AviatorDrama said:


> Ok, great, this sounds like a doable plan. I've tried to educate myself on the products you've listed and added all of these suggestions to the proposal. I think Plyron is quite a bit out of our price range, so Masonite will need to suffice. I'll call the local mom and pop, 40 yrs exp, to get an estimate based around your ideas.
> 
> Our stage is primarily used for middle school plays, musicals and band concerts, plus at least 7 weekends per year it is rented by local dance studios for their recitals. I don't suppose sprung dance flooring is warranted, nor would the district likely pay for it.
> 
> ...


those hard crowned wheels will account for the plywood damage. Use the flat rubber wheels. 

You do not remove screws or nail from the plywood. Re secure it to the floor joist. The Planipatch will fill them.

The Paint I like is PPG Break Through (in Wrought Iron color) low odor, fast dry, and it resists pull up from tape better.

Post pictures of all door, carpet, wall transition areas as well.


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