A high density tempered pressboard floor material is common. Frequently, but erroneously, referred to as 'meso' or 'masonite' this material comes in many different grades. Masonite Corporation no longer manufactures this category of product, but the brand name lives on like 'Kleenex' for tissue paper. Common tempered pressboard you can buy at the big box lumber supply houses is typically a very poor solution for stage floors. When it gets wet it swells-up and flakes apart, and the continued impacts it receives from heavy rolling stock and dropped platforms will also cause to to disintegrate.
What you need is a type of pressboard that is high density and durable, this is ANSI Class 1 or 2 material (generic flaky pressboard is typically ANSI Class 5 known as 'Industrialite'). Sierra Pine brand 'Medite FR' in a 1/4" thickness is a good product for this application. There are synthetic (plastic) stage flooring products also available, but the flame and smoke spread characteristics of the material are probably inappropriate for use in an assembly space as they would produce toxic black smoke if they burn. There is a rather expensive material that laminates tempered pressboard to a plywood backing that is called 'Plyron', and this solution is not recommended as you are spending lots of money to replace a section when the surface gets damaged when it is only the tempered pressboard surface that needs replaced. A good quality ANSI Class 1 or 2 decking layer can last 10-30 years, whereas as generic pressboard (ANSI Class 4 or worse) can sometimes last less than a year.
Historically, the tempered pressboard top layer of a stage has been secured to the underlayment layers with #12 philips flat head wood screws, but this is VERY labor intensive as each screw hole has to be pre-drilled and countersunk so the screw heads are flush with the surface and don't create a trip / snag hazard. The screws are typically installed at 16" o.c., but some floors are attached at 12" o.c.. The screw heads then become a bit of a problem as they get filled-in with paint over time and getting a screwdriver bit to re-engage them to remove them can be problematic. Occasionally the material is secured with staples, but this only works with the low-density ANSI Class 0 material - the ANSI Class 3 & 4 materials are too dense to use staples successfully.
A modern alternative to screwing the deck down is to use 3M brand VHB 'hurricane tape'. This is a very thin double-sided tape that is VERY strong. Strips of it are applied to the underside of the tempered hardboard and it is then laid on the floor. If you ever need to remove a section you just slip a piece of piano wire under it and cut it free. This only works if you have a smooth sealed underlayment layer to attach it to. If you have a banged-up hardwood or pine floor it will typically need to be sanded and sealed prior to installing the sacrificial decking layer.
Once the decking is laid and secured, the finish coating can be done several ways. The cheap but short-term solution is to use a paint like Rosco brand Toughprime. For a long-term finish a two-part application of Madison Chemical brand GemThane MG201 Sealer / Primer and a finish coat of AquaTech STC. This is a nice low-gloss black surface specifically developed for theatre stages.
So much for the hardware recommendations - let's talk about the big picture of what a stage floor is all about. Many stage floors (black box theatres included) are either concrete or hardwood laid directly on top of concrete. This is an inappropriate arrangement for the performing arts. The activity that occurs on the stage is active and involves movement that is every bit as strenuous to the human body as basketball or volleyball. The floor needs to have a sprung suspension similar (but not identical) to a basketball court floor. Note that I am NOT talking about the finish of the floor - I'm talking about the dynamic movement of the floor as it relates to performer's actions.
If the floor is already sprung, then the issue of just adding a sacrificial top skin is fairly easily resolved, however, if the floor is not sprung, then it would be irresponsible to cover-up 'wrong' with a fresh layer of 'wrong'. Injuries to performers due to working on hard (unsprung) floors is a well-documented issue, and to ignore this fact could expose the school to future litigation should injuries occur.
The necessity of springing the floor is not too dissimilar from the justification for providing sprung floor in gymnasiums (albeit, the spring characteristics are NOT the same for sports and dancing / acting). The injuries to joints and bones are commonly discussed throughout the industry, however, dancers will tell you that the constant pounding of your jaws during repeated vertical motion can clatter your teeth together and chip or wear the enamel veneer off of them - a sprung floor can provide a significant reduction of pain and damage in this area.
For some unknown reason, Architects love to specify tongue-and-groove wood floors for stages. The argument against hardwood or pine floors is that they are prone to developing grooves from heavy point-loads being rolled / dragged across them. These grooves can develop broken wood edges that can introduce very long splinters into dancer’s feet and other body parts that might slide across the floor (Yikes! That hurts just writing that sentence!). A hardwood floor requires much more vigilance (maintenance) to keep them safe from splintering.
For a good overview of stage floor construction and why it isn't as easy as it sounds, take a look at: http://theatreface.ning.com/profiles/blogs/floor-planning-whos-cutting
If you are considering actually replacing your stage floor, know that there are many more details than have been discussed here that must be addressed. Your school district should understand that this is not a gymnasium floor and the knowledge base need to properly specify a replacement for it is not likely to come from an Architect unless they have a consultant that is familiar with the intricacies of performing arts facilities. Involve someone that understands your needs in the process.
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Erich Friend
Theatre Consultant
Teqniqal Systems
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Original Message:
Sent: 09-10-2015 12:25
From: Georgann Lanich
Subject: New Stage Floor
We are looking at a new floor, or floor covering, for our stage. It is currently hardwood and gets messed up pretty badly with shows over time. The admin isn't quite ready to replace it with a floor that we can paint black yet. Do you have suggestions for a stage floor that floats or a cover that works well for you? Thanks for any suggestions!
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Georgann Lanich
Tallulah Falls GA
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