Judo Subfloor

As a lifetime student of Judo, I learned to land on all kinds of surface. But I did not enjoy all of them. My search for the perfect Judo floor started about the same time our players were bringing home medals. Such series of events made our judo school well-known in our area, and we signed up more recreational adult members. I was certain recreational adult players were enjoying the hard surface even less. In order to retain the members, I knew we need a 'better' floor. In summary, the 'better' floor has increased the membership through member retention and safety. Read on to find out more on how we built DIY (do it yourself) spring-loaded judo floor below.

Building Judo Subfloor at Irvine Judo Club

Spring-loaded, aerospace-grade foam judo floor is finished at Irvine Judo Club. Thanks everyone for volunteering your busy Saturday. See you on the mat!

Everyone helped out. It took 4 hours to finish.

Hand held power drills to screws the boards together. Took 2 layers of Oriented Strand Boards. It's the cheap roofing material from a local hardware store. We did NOT get the nice expensive plywood board. The springs are bolted to the bottom layer. The top layer was staggered and sandwiched.

Use less springs (12 springs per board) for softer floor. Use more springs for heavy-weight players (36 springs per board). We used 18 to 24 per board

Close up view of the spring used. 4 inches tall. Search "Palmer Spring"

Smile while at work #0

Smile while you work #1

Smile while you work #2

One giant tarp. Vinyl gauge 18oz. You can get any color you want.

4 inches tall springs.

Minamat is not an ordinary foam. Aerospace grade form comes in 4ft x 50ft. 3 inches thick.

Tarp + Foam + MDF board + Spring. Here only one layer of OSB board is visible, but there are two layers in there.

Everyone prefers the new floor. Notice the rise in height (yellow) over the tatami (green)

A well earned celebration.

Why this floor is special.

While everyone else is using these...

Cheapie foams are intended for the disposable packaging industry. The forms will lose their bounce over time because they absorb impact by being partially but permanently damaged hence disposable.

We are using these... Minamat™

High Quality Dense Closed Cell technology. This wonder material has a rubbery feel, good physical properties, low-temperature toughness, stress-crack resistance, and heat sealing properties and resistance to UV radiation. Quite inert and causes no reaction in case of accidental digestion. Will not lose bounce over time.


Minamat™ mats are made of top quality materials and superior workmanship.

Remain soft in summer and winter

Friction-burn resistant

UV and Ozone crack resistant

Moisture and odor proof

Minamat™ mats are safe and sanitary.

Minamat™ mats are economical.

Superior yet economical training floor surface for large Dojo area.

SUBFLOOR MATH: $1.86 per sq ft

Things you need for 1,000 square foot dojo (50ft x 20ft).

8ft x 4ft OSD board x 32 boards x 2 layers = 64 boards x $12 = $768

A box of deck screws = $20

Springs: 24 springs per board x 32 boards x $1.50 = $768

Labor: lunch and party = $300

TOPFLOOR MATH: $5 per sq ft

Use you own tatami or

Aerospace grade foam rolls: (50ft x 4ft) x 5 rolls x $800 = $4,000

Black duct tape for the seams between the foams (50ft x 3inches) x 4 rolls = $40

Tarp: Super Heavy Duty 18oz 50ft x 20ft custom cut = $1,000