Mat Matters

by Greg O'Connor, 5th Dan

You fall down. You get up. You fall down. You get up. You fall down. You get up. In Aikido training you interact with the mat as much as you do with your practice partner. A good mat enables you to train effectively. If your interaction with it does not involve blending then the mat is going to remind you that it is healthier to do so - and it can injure you toemphasis the point. A bad mat can injure needlessly. Therefore, the decision of what type of mat you and your members want to interact with should be thought out thoroughly.

Mats and their materials and methods of construction vary quite a bit. Deciding on what type of mat is right for your particular dojo involves considering such factors as the existing floor (is it concrete or wood?), personal preferences on resiliency (hard or soft?), durability and costs.

First of all - Is the floor wood or concrete?

If the existing floor is wood then the wood itself has a certain degree of resiliency. Therefore, you can generally just put a good mat material directly down on it. If the existing floor is concrete then additional protection should be considered, whether that is a "false floor" or additional cushioning material. Here also enters the debate about whether to have a "hard" or "soft" mat.

"Hard" Mats vs. "Soft" Mats

To paraphrase Goldilocks - "This mat is tooo soft. This mat is tooo hard. This mat - is juuust right!"

Some say a hard mat is more realistic. Having a hard mat insures that practitioners fine-tune their ukemi since it less forgiving. But being less forgiving may mean more injuries. Others say a soft mat reduces the chance of injury. A soft mat may be very forgiving and "beginner friendly" but it does not challenge the practitioner. It may be nice if you always fall on a mattress but what happens if you trip and fall on pavement or slip on ice? To get the benefits of both I suggest the middle of the road. The mat should be soft enough to minimize injury to your beginners, thus making it more accessible to more people, while at the same time protecting advanced trainees as they explore other more advanced methods of ukemi such as breakfalls, highfalls, etc. It should be hard enough, though, to demand that practitioners pay attention and hone their ukemi skills.

Mat materials

Depending on your budget, time and/or energy you've got some choices - from free to relatively expensive.

"Rubber Dust" and Carpet

Many dojos find it adequate to use materials such as "rubber dust," (a by-product of retread tire manufacturing), inexpensive carpet, or even a collection of carpet remnants with carpet underlay (commercial carpet padding). They are then covered by either canvas or vinyl. These choices may be used in cases of economic limitations, temporary needs or experimental curiosity. Rubber dust doesn't cost anything but takes finding a manufacturer and gathering it at the manufacturer's sight. It tends to shift over time so it is necessary to remove the mat cover and rake and level the rubber shavings periodically. Therefore, whatever cover you place over it should be easily removable to allow for regular maintenance. Carpet with carpet underlay would, by many, be considered inadequate protection against the effects of Aikido falling.

Commercially Manufactured Mat Materials

Closed cell foam
Example: Minicell (color: bright white)
It seems that if you have a dojo then, at some point, you will have a water leak - usually from the ceiling right down onto the mat.

Closed cell foam does not absorb water. That's a good thing. When covered with vinyl you have it made. Closed cell foam comes in a selection of thicknesses but I'd recommend staying at 1 1/4" to 1 1/2" thick. Any thinner may not provide enough cushioning or protection. Any thicker can allow for too much penetration of the foot thus holding the foot and causing stress or injury to the foot, ankle or knee when turning or twisting. A closed cell foam, such as minicell, has excellent resiliency, minimal penetration and recovers practically immediately to its original surface height. Minicell is typically manufactured initially in 4'x4' sheets and then glued together in larger sheets by the manufacturer or supplier depending on your specific size requirements. It is then rolled for shipping. About the widest a roll can be is around 12'. Wider, I believe, is not generally shippable. Keep in mind that you may also be limited in the length of the individual roll due to your door size since the longer it is, the thicker the diameter once it is rolled. The mat manufacturer/supplier should be able to help you determine what is best for your particular circumstances and needs.

Open cell foam
Example: Oletex, Trocellen (color: two layers of grey) Open cell foams absorb water, but this may not be a concern if entirely covered (on all sides and bottom) with vinyl. Generally it is slightly cheaper than closed cell. It has excellent resiliency and recovers practically immediately to its original surface height, although a bit slower than the closed cell. A side note: Ethefoam is also a common open cell foam - however, I don't recommend it for Aikido practice because it compacts quickly, especially at its edges.

Costs of closed or open cell foams can vary depending on supplier and total square footage being ordered. The more you order the more you can bargain on price. Base price is quoted on a per square foot basis. They can be ordered as, for instance, sections of 4' x 4' or in rolls of various lengths. They can both be ordered with vinyl covering adhered to individual mat sections by the supplier or can be covered by a single large canvas or vinyl mat cover.

Gymnastic Tumbling mats (colors: blue, red)
Be sure to get the proper thickness and resiliency for typical Aikido activity. Some tumbling mats may be as thin as one inch thick while others will be several inches thick. Again, about 1 1/2" thick is a good general rule for Aikido practice and you should still consider a secondary undersurface material if necessary. Tumbling mats are usually vinyl covered, foldable and fit together in a variety of ways using velcro attachments. If used without an overall single mat cover the gaps between the individual mats can catch toes and fingers during Aikido activity.

Commercial Tatami (colors: light green, blue, red)
These popular mats are manufactured to look like the traditional Japanese tatami mats used in Japanese homes. Tatami are woven straw mats. These mats are manufactured to those same general sizes (about 3'3" x 6'6" and about 1 1/2" thick) and are vinyl covered with a surface texture resembling the woven straw look of traditional tatami. They are initially expensive but will last practically forever. They can be cleaned and moved easily. They usually have a non-slip material on the underside to help prevent slippage but they may still need a containment method to keep them from separating. Examples of containment methods include a wooden frame around the entire mat, a belt system around the entire perimeter or a velcro border that is attached to both the floor and the mats. They also make for a harder mat - again much like traditional training tatami - but flatter.

Raised Floor ("False" Floor) Mat Construction

This mat, of course, takes some forethought, planning and preparation. To give you one example - at my ACNJ-Morristown dojo, since we had concrete as a base, I decided to combine some methods and materials already suggested, used and proven by other dojos and add my own ideas. The result was this: The first layer to come in contact with the existing cement floor are small 4" x 4" x 1 1/2" thick blocks of minicell. These blocks are glued to another layer of 3/4" plywood (1/2" has an unacceptable amount of bowing or warping). There are approximately 33 - 4"x4" minicell blocks per 4'x8' sheet of plywood. This layer of plywood has patches of velcro stapled to its top side which then matches up to a second layer of 3/4 " plywood with the matching velcro stapled on its underside. These two layers of plywood are staggered from each other so that no plywood seams match up making for a more stable and consistent surface. Our full minicell mat comes next, covered by #10 duck canvas. (For a cross-section of this construction see Illustration A.)

This is how it went. After the thinking came the planning. After that came more thinking, rethinking and planning. Then some more planning. Then came the ordering of the materials. All of the materials (minicell blocks, velcro patches/rolls, plywood, glue, hand rollers, brushes, heavy-duty staplers) were gathered on-site in the dojo space - ready for assembly. Dojo members were then organized into teams. We used an assembly line construction approach. One team glued, another stapled, another handled and stacked the plywood. Another took the completed plywood and placed it in its final position on the floor. The entire assembly of this 2400 sq. ft. mat was completed by about 15 volunteers over one weekend - with the majority being done by that Saturday evening.

To adhere the minicell blocks we used a glue supplied by the mat supplier. I cut out a pattern in taped-together showcard poster board (see Illustration B) that could be laid on top of a sheet of plywood. Using this cut-out pattern the glue team easily and quickly applied the glue to the cut-out spaces on the plywood. Minicell blocks were then immediately applied to those areas. The plywood sheet was then passed to the stapling team that used another showcard cutout pattern (see Illustration. C) to staple one layer of velcro to the other side. As this was being done a second stapling team was stapling the matching velcro to the underside of the top layer of plywood. (Whew! - I have to pause at the memory of it all!) An assembly team then laid out the first layer of plywood (minicell blocks down, velcro up) in its entirety. Once the first layer was in place the second layer of plywood with its velcro matching was attached and locked into the lower level's velcro. The full minicell mat was then rolled out and duct taped (or glued) at its long seams. The canvas cover came next. It was grommetted and laced to a pre-stained 4" x 4" frame that had been lag-bolted into the cement floor. Ta-Da!! As easy as finding a reliable inexpensive internet service provider. (Cough! Hack! - Excuse me.)

Wood Pallet False Floor
Wood pallets are relatively cheap, easily acquired, transported and, when need be, replaced. Check your local Yellow Pages for suppliers. Your mat material can be laid directly on top of a base layer of pallets. If one breaks you pull up your mat, take out the broken pallet and replace it with a new one.

As an additional note I've even heard of old tires being used as a false floor. They may provide for more bounce than most practitioners would prefer. The down side is that your students may feel "tired" all the time but then, on the up side, no matter what your dojo financial status you'll always have a "good year". (Sorry - you would have said the same if you were writing this.)

Carpet Underlay
A good carpet underlay (carpet padding) may be all you need to provide the initial cushioning barrier between your mat and the existing floor surface. It is inexpensive, lightweight, easy to transport and custom cut, and easy to acquire from any carpet supplier. However, I recommend a quality 1/2" thick or better, otherwise you might as well not even bother since the cheaper lower grade carpet underlays would not provide enough cushion and resiliency for your Aikido training.

Mat Covers

Canvas (color: off-white / natural)
Many feel canvas provides an ideal surface texture and feel for Aikido practice. Proponents of canvas give the following reasons for why they use it: canvas is a natural material (cotton), canvas has a certain feel, a "tooth" or texture, that both absorbs moisture and gives traction, canvas has a softer aesthetic off-white appearance and canvas is generally less expensive. Canvas, though, is difficult to clean and generally is only spot-cleaned as needed (blood clean-up for example). Large area cleaning tends to leave water stains either in long rows or large irregular patterns depending on how you clean it. It may be clean but it will look odd. Canvas
does absorb perspiration so it doesn't remain on the cover surface, as with vinyl covers, but it cannot be effectively deep-cleaned without compromising its appearance. Depending on how much use it gets canvas should be replaced generally within five years. Some dojos need to replace it almost yearly and some only every ten years, if that.

Canvas also comes in different "weights." A good weight to consider is a Number 10 Duck weight. This is a good medium weight material. Heavier can tear up feet, due to its coarseness, and lighter cannot be properly stretched to remove the wrinkling that can sometimes cause tripping and injury. Seams should be double-lock type (see Illustration D) and kept on the underside minimizing their exposure and wear. The double-lock stitch is an easier stitch for your canvas supplier; therefore it is cost effective. Double stitching these seams to the upper layer (see Illustration E) is not necessary since the seam flattens out sufficiently from use. Also the mat itself will wear at the same rate as the double lock seams so the additional cost of this double stitching offers no additional life or strength.

Vinyl (colors: white, blue, green, red, etc.)
Many feel vinyl is the best all-around choice for a mat cover. Vinyl is always easy to clean and maintain. Its cost is generally higher than canvas but if manufactured properly will last longer. Seams can sometimes be a problem depending on the manufacturer or supplier. To form its seam vinyl is overlapped and glued. If not properly and fully adhered the seam may tend to split and/or separate whether from the stress of stretching and use or from practitioners catching their feet on the raised lip of a seam.

With vinyl you have two surfaces to choose from on the same piece of material. One side will have more "tooth" or traction. The other side will be smoother or slicker. The "tooth" side provides traction and prevents slippage but may hold the toes, foot, knee, shoulder, elbow, fingers or hand too much causing a twisting injury. The smooth side will allow more movement but can become slick - especially since vinyl will not absorb the class's accumulated sweat and perspiration - itself a compromise since many times your face is down in that same sweat and probably you or someone else has repeatedly stepped in it as well. The up side is that it can be effectively and easily cleaned - even after every class. It is difficult to determine beforehand which side will be best for your dojo because you can't tell how the surface will truly perform until its actually down. If you can, check other dojo vinyl surfaces as you travel and ask their opinion.

Painted canvas
I've observed that painted canvas used to be a very popular mat surface on the U.S. west coast. My understanding is that the canvas is repeatedly painted and sanded until the desired surface is attained. This can be time and energy consuming, somewhat costly, as well as dust producing, but it can then be cleaned like vinyl while retaining some of the advantages of canvas.

Note: Both canvas and vinyl covers can be drawn over or under the outer mat frame and secured with washers and bolts which go directly through the frame and cover and into the existing floor. Both canvas and vinyl covers can be grommetted around the perimeter at 1' intervals and tied or laced to the mat frame in a variety of ways. The outer mat frame will still need to be attached securely to the existing floor to prevent it from being pulled up once the mat cover is being stretched and secured. Outer mat frame size is determined by the final height of your mat surface. It can be anywhere from 2" x 2" or 2" x 4", up to 4" x 4" even (gulp!) 6" x 6".

I'm glad to be able to have the opportunity to do this article for Aikido Online. Aikido Online is the perfect venue for such information. For years people have contacted me for advice on mats - especially after the article on mat construction that I had written in other Aikido magazines several years back. This article contains information on mat construction that I'm repeating to different people from around the country all the time. It's great to have a place where all the information is gathered and accessible to others. It is the same reason I wrote The Aikido Student Handbook. It is simply impossible to repeat all that information each time for every new student. This article can also be a work-in-progress as new methods of mat construction are developed and new mat materials become available. It is, by no means, the final say on training mats.

How did I get appointed the unofficial spokesperson on mats? It's not a position I actively sought out but I'm happy to share my experiences if it will help others. Having either founded or co-founded between ten to fifteen dojo spaces over the years has, indeed, given me the opportunity to experiment with a variety of situations, needs, materials and methods. I've had both smooth and rough vinyl sides as well as different canvas covers.I've experienced "rubber dust" as well as other mat materials and combinations. Currently at my four locations there is a wide variety of mat types ranging from minicell to trocellen to Swain Sportsmats. I'm comfortable with recommending any and all materials and methods depending on the individual situation. I hope my experiences can help you in your decisions.

So that we can better help our training friends please feel free to contact me with your personal comments, findings, experiences and observations as well as any local sources of mat materials and options.

Greg O'Connor, Chief Instructor
Aikido Centers of New Jersey
42 Bank St., Morristown, NJ 07869
973 898 9858