The Dojo is doing well!

Update:

Since my last post, I thought some of you would be curious as to how well my home-made dojo has survived. In short, the dojo is performing very well, and seems unaffected by extremes in temperature (after all, this is a garage). If you notice from the photos, I decided to take down one post on the interior side of the mats, as the car door didn't agree with its placement. I did keep the exterior post, so that I could still utilize the "ukemi training pole", but more importantly, the exterior post is anchored to the wall, and the frame that surrounds the mats. The weight of the mats on the sub-floor would not result in much if any shifting, but I think the frame and anchoring was the right thing to do for such a small footprint; a larger set up would not likely require such additional work.

How does it feel?

In comparison to the "other dojo" where I train, my garage dojo is definitely taut (more BMW than Cadillac), but certainly not uncomfortable for hard falls. In fact, I used 33 blocks per 4'x8' area, so I expected a slightly harder surface as the foam performance would be very fast.

I had used a foam underlay between the sub-floor and the tatami mats, primarily to protect the mats from the deck screws. Another option, although more expensive, is carpet underlay, which can be used to tweak the hard-to-soft response of the mats. The "other dojo" I attend uses carpet underlay and there is a distinctive difference in response upon landing (I may try it out one day on my own mats).

In the end, I am quite happy with my dojo, and it serves me well. Each person is different, and I recommend trying a variety of materials or thicknesses under the tatami until you find the right mix.

My Dojo now:

Introduction

I have created this blog in order to share my research. If you like to "roll" or get "thrown" onto a tatami mat, this blog may be of some assistance. A few weeks ago, I decided I would invest in tatami mats to create my very own "garage dojo". I realized that simply applying tatami to concrete would be a brief experience, with perhaps long term pain, and so I began to search the web for answers.

I found an article by Paul Nogaki entitled: The Quest for the Perfect Judo Floor (http://judoinfo.com/new/alphabetical-list/research/468-the-quest-for-the-perfect-judo-floor). In comparison to other articles I found, some advocating layering with puzzle mats, or using slats in a basket weave pattern, etc., I found Mr. Nogaki's research and instructions very helpful.  Basically, the sub flooring is meant for the high falls associated to Judo (or Aikido), and uses a very simple method: foam blocks under two layers of 1/2 inch plywood. In the article, Mr. Nogaki explains the rationale and science behind this approach, and I would not attempt to paraphrase. However, there are some details that need clarifying, and these are details one needs if there is an intention to build a similar sub floor.

Shopping List:

1. 4"x4"x3" Trocellen Polyethylene foam blocks 2.2 lb density per cubic foot. (purchased direct from manufacturer at less than $1 per block: www.wifoam.com). Tim Lang works for Wisconsin Foam Products, and has extensive experience providing services to Judo Clubs.

2. 1/2 plywood (you need one layer to apply the foam blocks, and the second layer to tie it all together-remember to overlap the joints). - You can either apply 27 or 33 foam blocks to each 4' x 8' sheet of plywood. The general pattern is 3 blocks across 4', spaced evenly, with subsequent rows offset. The pattern for 27 & 33 block configurations was provided by Wisconsin Foam Products, and a template with measurements will be included in the next post.

3. Wood screws (Outdoor deck screws are great).

4. Spray adhesive (not damaging to polyethylene - there are several options for application and strength of bond).

5. Tatami mats (I bought new Zebra 1.5 inch Judo mats, however, there are several other brands that are very good as well. I chose Zebra because the mats are German made, and are excellent quality).

Optional Items:

a. Sub floor adhesive (Stronger bond, prevents the screws from popping, and reduces/eliminates squeaking).

b. Under padding on top of the sub floor to reduce movement, and to protect the bottom of the tatami from the wood screws.

c. Mr. Nogaki used Velcro to keep tatami mats attached to the sub floor. I was not too keen on applying a permanent adhesive to my tatami's, and so I plan to use 2"x6"x8' to create a frame around the sub floor.  The frame will be attached to the interior garage wall, and prevent the floor from shifting.


Pictures and build comments to follow.

Pic's and Explanation

As of today, I completed the sub floor, set the tatami mats, and boxed in the outer frame. A few minor details remain, but the process was simple. The following is a brief pictorial explanation:

First, my beautifully "made in Germany" Red Zebra Tatami's.

I set up a temporary right angle using two 2"x4"'s.

From this starting point, I laid out my tatami mats in the configuration I wanted, and then placed the first layer of plywood, making the appropriate cuts to ensure a nice tight fit. 

This pattern was slightly over 16' 6" long, and 6' 7" wide. I used 4 pieces of 4'x8' plywood, and utilized the cut-off to make up the deficit in length. From this pattern, I reversed the "image" and made cuts to overlap the joints. This second layer is now the "bottom" of my sub floor, and will be measured for the application of foam blocks.

The foam blocks, provided by Wisconsin Foam Products [www.wifoam.com].

The blocks are roughly 4"x4"x3" and are direct from the manufacturer. I purchased 133 blocks at $0.87 each. (The more you buy, the less it costs. Denver Judo Club bought many, and only paid $0.27 for each block). These are high density foam, and are not like the soft foam puzzle mats.

As provided by Wisconsin Foam Products, Tim Lang [tim@wifoam.com] forwarded two pdf template drawings that were designed for Denver Judo Club. This example is for the 33 block configuration.

[If you require the actual template, contact Tim Lang]

The next step is to mark the floor. According to the template for 33 blocks, the pattern is designed for a full 4'x8' sheet of plywood. As my area is uneven in width and length, I marked each plywood piece from the outside in.

I placed the blocks first before applying adhesive. [Note: this will take longer, so if you are very confident in yourself, just start at one corner and go for it. On the other hand, if you are like me, I tend to mark things twice, even three times before I cut, nail or glue]. The technique I used was to apply adhesive to two blocks and then hold them down for 10-15 seconds to make a good bond.

I used a high strength adhesive by 3M, and although it seemed to snap, crackle, and pop like Rice Krispies, there was no deterioration of the foam or weakness in the block. Read the label before you buy.  There are spray adhesives specifically for foam materials.

Keep in mind those joints, and the fact this is a reverse image of what will be placed on the ground. I left the blocks overnight to properly cure. This marks the end of day one, and 2 1/2 hours of my time.

On Day 2, I began the process of disassembly and reassembly right-side-up:

To ensure I did not forget the order, I marked each plywood board based on orientation [Ex. 1RW (1 Right Wall), 2R (2 Right), 3LW, 4L, 5E (5 End)]. I also marked an arrow in the direction the plywood should face when turned over. [Consider this a method for dummies, or distracted Father's on parental-leave].

The next step is to reorient the pieces right-side-up.

Notice that my blocks have now elevated the floor by 3"+ another 1" for the two 1/2 plywood layers. I added the 2"x10" to ensure everything remains relatively square.

Once I have set the first layer in place, I prepare to add the second overlapping layer. I decided to use a sub floor adhesive and non-corrosive 1 1/4" deck screws to ensure a strong bond, and no squeaking.

I used two extra large tubes of adhesive, and two boxes of deck screws. 

After completing the second layer, I can immediately start the process of laying down tatami. But, before I do, I add a layer of foam underneath to create some traction and protect the tatami from deck screws that might pop out.

The foam flooring can be tricky to keep in place, so I used the balance of my spray adhesive to keep the corners down. 

Finally, the tatami's are set in place.

I mentioned before that Denver Judo Club used Velcro to keep the tatami in place. However, I did not want to attach a permanent adhesive to the bottom of my new tatami, and thought it better to "box" the entire sub floor with a 2"x6" frame that is set just below the top of the tatami mats.

The frame itself is not attached to the sub floor. I assume the entire assembly is heavy enough to remain in place, but in case I am wrong, I will attach the frame to the side wall. Although not "perfect", it is close, and I will use the remaining foam flooring to shim the outer frame side of my tatami's. This will ensure there is no shifting of the mats.

This was the end of Day 2, and I spent 3 hours completing the floor and frame.

Final details to follow.

Final Details

According to the Denver Judo Club, they used industrial strength Velcro (available at Home Depot for $27 per 2"x15' strip, or $18 on Amazon). I would have used this same process, however, my needs were slightly different than a typical Judo sub floor. As well, DJC was most likely building the sub floor to last a long time, and therefore a permanent solution was more desirable.

In my own case, I hope to expand the number of tatami mats for a future space, and did not wish to affix any adhesive or other permanent options. The idea that followed was to create a non-attached box frame around the sub floor, that would serve three purposes: 

1. To keep the sub floor from shifting out of place.

2. To keep the tatami mats from shifting out of place.

3. To mount to the side wall, and cradle to posts designed to carry a metal cross bar approximately 7' long.

Because of the uneven length of the sub floor, I used 2"x6"x16' cut in two pieces, which left a gap of approximately 6". I used this gap as the spot where my post would be mounted to the frame. 

As the 2"x6"x16 cut into two pieces loses its restraining abilities, I have no choice but to use concrete anchor screws in order to keep the post in place, and prevent the mats from shifting.

With the concrete screws and steel angles in place, the frame and the post are solid. The post on the wall side is shimmed and screwed and is also quite solid. As I stated earlier, the floor is not perfectly square, partially because I wanted to get this floor completed as quickly as I could. Despite the small gap between the outside frame and the mats, the space is easily resolved with pieces of foam mat used to shim the tatami mats at the corners and joints.

Finally, I use simple steel angles and joist hangers to create two levels for my 7' steel cross bar. 

Although the posts have nothing to do with Judo, they are a training technique for practicing high falls to the side. As I intend to practice in my garage dojo without a partner, the entire assembly is meant for practicing Ukemi. Certainly, there is enough room for a partner, albeit in a controlled circumstance.

The final product:

In conclusion:

The basic premise of Mr. Nogaki's article can be used for any size dojo, as one can see from my blog. Excluding the cost of tatami mats, I spent roughly $275.00 on materials and spent 6 1/2 hours completing the work over three days. The foam block sub floor is a simple yet amazing concept and I encourage anyone who intends to build a "Judo sub floor" to read Mr. Nogaki's article posted on www.judoinfo.com (you will find the direct link to the article in the Introduction section of this blog) Many thanks to the information provided by Mr. Paul Nogaki / Denver Judo Club, Tim Lang of Wisconsin Foam Products, and Patrick McCarty of Zebra Mats who were incredibly helpful. Were it not for their willingness to share their knowledge and expertise, I would have suffered many hours of uncomfortable Ukemi. I hope you find my garage dojo project helpful.

Resources:

www.judoinfo.com

www.zebramats.com  Patrick McCarty, patrick@zebramats.com

www.wifoam.com  Tim Lang, tim@wifoam.com

Enjoy