A Steel Sled on a Stage Floor: What ANSI E1.34 Measures, and What It Leaves Out
By Walkway Management South Florida
There is an American National Standard for how slippery a stage floor is, and almost nobody outside theatre engineering has read it.
It is ANSI E1.34, written by the Floors Working Group at ESTA, the Entertainment Services and Technology Association. The full title is “Entertainment Technology — Measuring and Specifying the Slipperiness of Floors Used in Live Performance Venues.” It was published in 2009, then reaffirmed in 2014, in 2019, and again on 29 February 2024, so the document in force today is ANSI E1.34-2009 (R2024). ESTA gives it away.
I read the whole thing, clauses and annex, rather than the abstract. The honest result is that it does several things better than I expected, and that its real weaknesses are not the ones you would guess from outside.
What it gets right, and I want to be specific
It measures sliding friction, not the stick at the start. This is the thing I assumed it got wrong, and it does not. Clause 4.3.2 says readings begin “from a point 500 mm from the start of its travel.” That first 500 mm is precisely where breakaway and stiction live, and the standard throws it away. Clause 4.3.1 sets the pace at “a normal walking pace, which is about one meter per second.” Clause 6.1 calls the result the coefficient of sliding friction.
That matters. The failure that got ASTM C1028 withdrawn in 2014 was a static measurement returning comfortable numbers for floors that were dangerous in motion. E1.34 sidesteps it by design, measuring a moving contact at roughly the speed a person actually moves.
The contact load is deliberately reasoned. Annex A.5.2 explains that the sled weight per unit of contact area “is approximately that of a 75 kilogram (165 pound) person standing on the ball of his foot,” and says plainly that although friction is theoretically independent of contact area, the procedure should “roughly duplicate the situation when a performer is standing on the ball of one foot.” Someone thought about how much the floor deforms under a real load. That is more care than many methods show.
The field procedure is right where most standards are wrong. Clause 4.1.2: if the test is in the field, “do not clean the material but test it as it is in the field.” Testing a floor in the condition you found it is the correct instinct, and the number of methods that quietly assume a scrubbed surface is larger than it should be.
It tests in two directions. Clause 4.3.3 requires at least three runs one way and an equal number perpendicular to them. Directional variation is real on grained and extruded surfaces, and plenty of methods ignore it.
Annex A is unusually candid. It works through pulley friction, cord angle and scale linearity as error sources, and gives three practical remedies for the cord-angle problem. A standard that documents how its own rig can mislead you is being honest with its reader.
This is not a careless document. Now the parts that concern me.
Problem one: the standard says its own headline number is for marketing
Clause 2 describes the General Testing Procedure, the one using stainless steel feet, and then says this:
It is likely to be useful for marketing purposes and for comparisons between floor materials, but it may not be representative of the slipperiness experienced by a performer in a particular situation, since the performer is unlikely to have footwear with soles and heels made of stainless steel.
That is the standard’s own text, and it names the problem precisely. It is honest to the point of being disarming.
The difficulty is what happens next. Of the two procedures, the General one is the only one producing a comparable number. Run the Specific Procedure and you get a value tied to one sole compound on one floor, which cannot be held up against anything else. So the procedure that generalizes is the one the standard calls useful for marketing, and the procedure that reflects a performer will not travel between products.
In practice the number likeliest to reach a product sheet, a rider or a specification is the steel number, carrying a caveat that lives in clause 2 of a document almost nobody downstream will open.
Steel is also a poor stand-in for a sole. Shoe friction has an adhesion component and a deformation component, where a soft sole flows around the high points of the surface and has to be pushed back out of them. A rigid type 304 foot with a 7 mm flat tip has essentially no deformation component. It rides the peaks. Two floors can return a similar steel number and behave completely differently under a dance shoe.
Problem two: there is no contaminant procedure at all
This is the largest gap in the document, and it is an omission rather than an error.
Clause 4.1.1 covers the quality-control case: wipe the area “clean with a dry cloth to remove any dirt, dust, or other contaminants.” Clause 4.1.2 covers the field case: test as found. That is the entire treatment of surface condition.
There is no wet procedure. No water, no specified contaminant, no wetting agent, no instruction on applying one, no separate reporting for a contaminated condition. The standard measures dry floors, or whatever happened to be on the floor when you arrived.
Consider what is actually on a performance floor. Sweat, in quantity, on any dance surface. Haze and fog fluid residue, which settles across a whole stage over a run. Stage blood. Spilled liquid in any scene with a drink in it. Rain and water effects. Fake snow. Confetti dust. Dry ice condensate. The traction products dancers put on their own shoes, which transfer to the floor.
Every one of those changes the friction, and none has a procedure. Compare that with the methods built for walkway surfaces, which treat the wet condition as the governing case rather than an afterthought, because wet is when people fall. We set out how those differ in SCOF vs DCOF vs PTV.
The field clause partly rescues this. Test as found on a hazy, sweaty floor and you have measured something real. But you have measured it with no way to reproduce that condition, compare it against another day, or specify it in advance. An uncontrolled contaminant is not the same thing as a controlled one.
Problem three: it produces a number with no pass mark
Clause 6 is two sentences. Divide the average force by the weight of the sled. Report that number as the “slipperiness” of the floor surface material.
That is the end of the standard. There is no minimum, no maximum, no range, no band, no classification, and no guidance on what any value means.
This is the part I find genuinely odd, because clause 2 shows the working group understood the real problem. It describes the Specific Procedure as useful “when a performer reports that a floor is too slippery or too sticky.” Too sticky. They identified in 2009 that a performance floor has a hazard at both ends, which is exactly right and is something general walkway standards still do not address.
A floor that grabs is its own injury mechanism. When a dancer pivots and the shoe holds while the leg keeps rotating, the load goes into the knee. Ballet wants controlled slide through turns. Tap wants bite for sharp stops. The correct answer for a performance surface is a window, not a floor value.
The standard names the window problem and supplies no window. It hands you a measuring device and leaves what the measurement should be entirely to you. A venue can follow ANSI E1.34 perfectly, generate a defensible number, and still have no idea whether the floor is right.
Problem four: a spring balance, read by eye, at walking pace
Clause 3.2 permits a spring balance or tension gauge. Clause 4.3.2 says the readings “shall be observed and recorded” as the sled is drawn along.
Put those together and picture it. An operator walks at one meter per second pushing a stick ahead of them, watching a needle on a gauge mounted at the top of the handle, recording values at three or more points at least a meter apart. The needle is responding to a sled sliding across a real surface, so it is moving.
Annex A.3.2 is candid about the instrument. It notes that lab-quality force gauges are available for under $1,000, then adds that “fish scales that are claimed to be able to weigh with this accuracy are available for less than $100.”
The annex’s reasoning for why a cheap scale is acceptable is actually sound. The same scale weighs the sled and measures the draw force, so absolute accuracy cancels and only linearity matters. That is a clever piece of metrology and I have no quarrel with it.
My concern is the human in the loop. A gauge that is perfectly linear is still being read visually, in motion, by an operator who is also walking and steering. Nothing in the standard requires data logging, a peak-hold function, or a recorded trace. Two competent people can follow every clause and disagree, and the document carries no repeatability or reproducibility statement to tell you by how much.
Problem five: spurious readings may be rejected, and spurious is undefined
Clause 4.3.4, in full: “The mean of the spring balance or force gauge readings over the runs shall be calculated. Obviously spurious readings may be rejected, but the cause of the spurious readings should be investigated.”
Investigating the cause is good practice. The difficulty is that “obviously spurious” is carrying real weight with no definition behind it. There is no outlier criterion, no limit on how many readings may be dropped, and no requirement to report that anything was dropped at all.
On a method where the operator both takes the reading and decides which readings survive, that is a wide door. It is the kind of clause that is harmless in a quality-control lab and becomes a problem the first time a number is contested.
Problem six: nothing validates the rig against how people move
E1.34 has no normative references. It cites no other standard for calibration, and it sets no validation requirement for the apparatus beyond the internal consistency of weighing the sled with the same scale used to pull it.
The wider field moved on this. ASTM F2508, first published in 2011, established a way to ask whether a walkway tribometer agrees with what happens when real people walk, by testing against reference surfaces whose slip potential came from human subject walking trials. An instrument that tracks those surfaces has an evidence-based claim to describing human slipping. One that has never been through it rests on the reasoning of whoever designed it.
E1.34 was published in 2009, two years before F2508 existed, and has been reaffirmed three times since without revision. A reaffirmation carries a document forward, it does not add references. So the sled sits outside the framework the rest of walkway tribometry now uses to establish credibility.
Here is the strongest argument against my own point, and it deserves the space. F2508’s human subject work was built around ordinary straight-line walking at a controlled speed. Performers are not doing ordinary walking. Validating a stage-floor instrument against a walking study would tell you very little about a pirouette, a slide, or a landing. E1.34 sitting outside F2508 is less an oversight than a genuinely hard problem, because the validation science for what dancers do largely does not exist.
That is an argument for building it. It is not an argument for leaving the gap unmarked, and anyone holding an E1.34 number should know that nothing behind it has been checked against human movement of any kind.
Problem seven: the scope line is honest, and routinely crossed
Clause 1 is admirably clear:
This standard describes means of measuring and specifying the slipperiness of floor surface materials used by performers in live entertainment venues. The standard is not intended to be applied to normal walking and working surfaces, but only to those floor surface materials used by actors, dancers, and other similar artists when rehearsing or performing.
That is a responsible thing for a standard to say about itself, and it is the line most likely to be crossed, because of what a venue actually is.
A theatre is a stage plus a great deal of ordinary building. The lobby and box office. The bars. Restrooms. Every corridor, plus the stairs and their nosings. A loading dock, a crossover, dressing rooms, ramps.
On the stage, trained performers move in rehearsed patterns in controlled footwear. In the lobby at intermission, several hundred untrained people in whatever they wore that night move in unrehearsed patterns, some holding drinks, some older, most heading for a restroom they have three minutes to reach.
The second group is where premises liability claims come from, and E1.34 correctly says nothing about them.
The failure mode is subtler than a wrong answer about a lobby. A venue tests the stage floor, files a document with a coefficient of friction on it, and comes away believing it has addressed floor safety in the building. The stage is the one surface in the venue where the people are trained, warmed up and rehearsed. Everywhere else is a normal walking surface carrying a normal walking public, and those get assessed with the methods built for them: the Pendulum Slip Tester under ASTM E303, and field DCOF under ANSI A326.3 where a comparison over time is what is wanted.
What I would do with it
Use the Specific Testing Procedure and treat the General one as a product-comparison tool. The standard tells you which is which in clause 2. If a performer says the floor is wrong, the sole material they actually wear is the only version of the test that speaks to it.
Record the floor’s condition every time, in detail, because the standard will not do it for you. What was on the surface, how long since it was cleaned, what had been hazed or spilled during the run. Without that, a field number measured as found cannot be compared to anything, including the same floor next month.
Build your own window and write it down. Since clause 6 gives no criteria, the useful move is to measure your own floors while they are working well, with the shoes actually in use, and keep those values as the reference. A number that means nothing in the abstract means a great deal once you have twenty of them from surfaces your company was happy on.
Log rejected readings. If you drop a value under clause 4.3.4, record that you dropped it and why. That costs nothing and closes the widest gap in the method.
Do not let a stage number stand in for the building. The lobby, stairs, restrooms and bars are normal walking surfaces carrying the public, and they need assessing on their own terms.
The larger point
ANSI E1.34 earns its place in the standards library, and I want that on the record after seven sections of criticism.
It exists because a working group recognized that performers have a friction problem general walkway standards cannot describe, and that they are exposed at both ends of the range rather than only the slippery end. That recognition was correct in 2009 and nothing published in the United States since has replaced it. The mechanics are better reasoned than the abstract suggests, and the document is candid about its own limits in a way that is genuinely rare.
What has not happened is the next step. Seventeen years on, the method still has no wet procedure, no acceptance criteria, no repeatability statement, and no validation against human movement. Those are not small omissions in a document whose output gets reported as “the slipperiness” of a floor.
A reaffirmation date of 2024 on a 2009 method is worth knowing before anyone leans on the number. So is the fact that the standard tells you, in its own clause 2, which of its two numbers is the marketing one.
This article is informational and describes slip resistance measurement practice and published standards. It is not legal advice. Standards are cited by designation and edition and may be revised; verify the edition in force for your application. Clause references and quotations are taken from the full text of ANSI E1.34-2009 (R2024) as published by ESTA on 11 March 2024. No single friction value, from any method, establishes that a floor is safe.
