What are Gym floors made of?

Written by: John Scillieri
Last Updated: April 2, 2020

Almost exclusively, maple is the go-to wood used for gym floors, dance studios, and stages. For decades, maple flooring has been the standard used for sports floor construction. But why? Indeed, there are many different species of hardwoods that are just as durable and aesthetically-pleasing as maple. The difference is, maple also offers shock absorption, unlike most other types of woods.

For this reason, maple wood is the safest flooring material to use for gyms and other athletic facilities. It’s durable, widely available, and flexible enough to withstand high-intensity foot traffic. Below, we’ll explore in more detail what gym floors are made of and why.

The Janka Hardness Rating: What gym floors are made of

In 1906, an Austrian wood researcher named Gabriel Janka invented a scale for measuring the hardness of wood species. The American Society for Testing and Materials, or ASTM, further standardized the Janka scale. The scale is still used today to determine the durability of one wood over another.

The room where a particular type of hardwood floor will be installed will ultimately determine its required place on the Janka scale. Rooms with higher foot traffic will need a harder wood. For gyms, especially, a wood that scores highly on the Janka scale is critical.

The scale runs from zero to 4000. No wood on earth scores zero, and neither does a wood score as highly as 4000. Balsa wood is the softest wood and scores a 100 on the Janka scale. It’s mainly used to make crafts. But the harder and tougher a wood, the more difficult it is to saw.

Where the wood falls on the scale is determined by a test that measures the PSI of how much pressure it takes to push a steel ball halfway through a wood plank. Maple scores 1450 on the scale. In contrast, Douglas Fir, another popular flooring choice, scores 600, whereas Brazilian Cherry scores 2350. Where a wood species falls on the Janka scale will not have any impact on its price.

Why is the Janka scale relevant when it comes to installing sports floors? A plank of wood like maple that scores highly on the scale won’t scratch, dent, or chip very easily. But at the same time, maple is flexible enough to withstand foot traffic and also make athletic activities safer for game players.

Flexibility and Shock Absorption in Maple Floors

Playing a game on a hard surface with no give can put undue pressure on the joints. It will also lead to a range of different injuries and low-back issues. For athletes, playing on a floor that is durable yet offers decent shock absorption is crucial for preventing injuries and wear-and-tear on the body. And maple is a flooring material that delivers on all these fronts.

For one thing, maple planks respond to people’s steps by bouncing back, ever so slightly, which reduces shock on the spine and knees. Also, the floor will offer a boost to bouncing balls when the floor responds to the contact. Not only is maple a safer wood to use, but it also contributes to the gameplay.

A Note on Sub Floors

The type of subfloor installed in a gymnasium will also enhance maple’s ability to absorb shock and flex to the movement of sports players. For gyms, a subfloor of plywood planks is typically installed over a slab. Then, maple flooring is installed. Although, this is a somewhat simplified version of the process.

For gymnasiums, though, the plywood subflooring is designed for maximum shock absorption to enhance maple’s flexibility. Subfloors for dance, yoga studios, or stages will need to have a different subfloor installed. The activity levels and types of the facility will determine the safest and most effective subfloor design to use.

The Different Grades of Maple a Gym Floor is Made of

There are three different grades of maple that facility owners can choose from:

First Grade
Second Grade
Third Grade

Mostly, the difference between these three grades of maple flooring comes down to appearances and costs. The flooring’s grade doesn’t have any bearing on the overall quality of the wood, its durability, or shock absorption.

First Grade Maple Flooring

First grade maple flooring is the most expensive option. This grade of wood has a limited supply, and it also requires additional labor to mill and bring to market—unlike the other categories. First grade maple flooring is virtually free of defects, knots, and other markings. As such, it offers a smoother, more uniform appearance in color and contrast.

Second Grade Maple Flooring

This grade of flooring allows for some knots and variations in the wood. But, the knots do not occur on the edges or ends of the planks. It allows for more significant variations in the wood for a lesser cost than first grade maple.

Third Grade Maple Flooring

Here, there are many marked variations, colors, and contrasts to third grade maple planks. Some people prefer the appearance of third grade maple, in that it could be argued that it’s more rustic and charismatic looking. Also, the range of variations in the planks will make the finished floor appear darker than either of the other grades of maple. A general rule of thumb is that first grade maple will be the lightest of the categories.