Hitting the Hardwood: Time for Hard Maple Sports Floors to Shine
March 6, 2012
With “March Madness” upon us, now is an appropriate time to take a look at what’s new in maple sports surfaces. The old “gym floor” has come a long way over the past 25 years. They are safer and better engineered – a more sophisticated flooring system. Sports surfaces are now required to meet more stringent U.S. and international standards for installation, safety and playability.
Basketball has grown in popularity around the world, thanks in large part to the Olympics. Volleyball is also a wildly popular international sport and is played mostly on hard maple. The nice thing about the source and supply of the hardwood is that maple trees only grow in North America. The hardness and tight grain of “hard maple” make it ideal for indoor sports surfaces.
For over 100 years, the Maple Flooring Manufacturers Association (www.maplefloor.org) has been the recognized authority for hard maple flooring standards and source of technical information. It is comprised of six manufacturing mill members, various allied manufacturers, distributor members, and accredited sports floor contractors.
There are a multitude of floor systems from which to choose depending upon the competitive level and intended use of the floor. Whether your project is for an elementary school, high school, collegiate or professional level, there is a system engineered to meet the specific interaction between both the sport and the athlete.
Maple gym floors are predominantly made in two thicknesses: five quarter (1”) and four quarter (3/4”), and two widths: 2-1/4” and 1-1/4”. For lower budgets there is also a Fingerblock pattern that can be glued direct to concrete. Most gym floors have a subfloor system designed, from a biomechanical standpoint, to provide just the right amount of shock absorption and playability characteristics – to allow shock attenuation and return of energy to the athlete – while providing optimum athletic sport playability, i.e. proper basketball “bounce.”
I may be getting quite a bit technical from this point on, but the science of sports floors has changed so dramatically over the years that there is no simply way to examine these changes.
In the past 20 years or so, the MFMA addressed a movement within the industry to actually quantify performance characteristics that best define “a good sports floor.” The first such attempt was to adopt the Din Standards that were developed in Europe during the 1990s.
The Din Standards measured various dynamics between interaction of the athlete and ball deflection to determine the amount of deflection within a given area of the playing surface. Primarily it measured area of deflection and vertical deflection.
But in the MFMA’s desire to test and create ideal performance standards, they more recently developed the Performance and Uniformity Rating, or “PUR” Standards, which also included testing measurements of shock absorption, basketball rebound and surface friction as well as area of deflection and vertical deflection. In so doing, the MFMA demonstrated its responsibility as the sports flooring authority by recognizing the importance of a sports surface’s uniformity and consistent game play for a high-quality floor. They therefore established the following uniformity requirements for each characteristic (listed in the MFMA website) as follows:
- Shock Absorption – 50% minimum average. Shock absorption measures the ability of a system to reduce impact forces felt by the athlete.
- Area of Deflection – 20% maximum at all test points. Measures a floor systems ability to isolate movement of an athlete’s impact.
- Basketball Rebound – 93% minimum average. Measures the basketball response off a floor system.
- Vertical Deflection – 2.3 mm minimum average. Measures a floor systems ability to yield under foot during game play activities.
- Surface Friction – 0.6 minimum. Measures the slip slide characteristics of a finished floor system.
The goal and objective of defining and developing these standards utilizing exacting testing methodologies is to assure that customers receive a reliable, well performing, competitive sports floor. So as you can see, both performance and uniformity are necessary to achieve a quality sports surface. And today the industry actually now understands the scientific relationship between the athlete and the sports surface. When a specific floor is MFMA “PUR” compliant, it is understood that testing is on a strict pass/fail evaluation. To avoid confusion, a floor is either compliant or it is not.
Regarding installation, the newest industry standard for hard maple sports surfaces has to do with the moisture content of the concrete slab underneath the maple sports flooring system. Effective Oct. 1, 2011 the MFMA only recognizes relative humidity (RH) testing for concrete slabs. This is to ensure the overall success of an installation as the slab’s moisture content should be tested prior to installation to make sure it is “dry.”
The MFMA recommends that the relative humidity level for a concrete slab for a non glue-down maple floor system is 80% or lower and for glue-down systems it should be 75% or lower prior to installation. There are many benefits to “RH Testing” including the ability to minimize the potential of moisture related problems in a new maple floor installation. It is also easier to use and is more accurate than previous methods like the calcium chloride evaluation or polyethylene film test.
RH testing is done by embedding probes into the concrete. This eliminates variables caused by changes in air temperature and humidity. The RH embedded probes are not influenced by finishing, curing compounds or surface coatings. Additionally, the RH probes provide readings deep into the concrete slab for greater accuracy. And lastly, RH testing allows continuous reading from the inserted probes throughout the curing process. This new technology and process is good news for installers and owners alike as it greatly eliminates what has historically been the number one problem associated with the installation of hard maple sports surfaces.
Now that you have filled out your brackets for March Madness, while watching your favorite team weave its magic on the hardwood, you will now have much more knowledge about sports surfaces and the role they play for the athlete than you previously thought possible.