Earlier this evening I finished most of the construction of our new 8x8 Olympic platform. It was surprisingly inexpensive and easy to build — about $360 total, including about $70 for delivery of the plywood (I don't own a truck).
There are four 4x8 pieces of cheap pine plywood that form the base of the platform. It'd be possible, of course, to splurge and use expensive plywood for the base, but that seems like overkill to me.
I assembled those four pieces crosswise — two on the bottom, and two on the top at a 90° angle to the bottom pieces. Once those were screwed together, I cut the 4x6 3/4" stall mats. These were shockingly cheap at my local tractor supply store — $60 for two mats, which is only $1.25 a square foot. By contrast, the Regupol flooring we have at Styrka was about $2.20 a square foot. I almost wish I'd used the cheaper mats for the whole gym and probably saved a couple thousand dollars, but in all honesty they have quite a few more imperfections, both functionally and cosmetically.
Anyway, once I cut the mats into 2x4 strips, I placed them along the platform. I placed our top piece — a nice piece of oak plywood — in the center, just to make sure everything was reasonably well lined up. Then, I used a cordless drill to drive screw the mats into the base.
Finally, with the help of a member, I flipped the whole platform over on top of the oak piece. Once aligned, I drilled screws in from the bottom up so that no screws would show on the center platform. We flipped it back over, and presto.
The last thing to do is add a frame. I'll be using Rogue's 8x8 frame. This will give the platform a more professional appearance, but it will also protect the wood from accidental chips.
I built this platform using the template provided by AthleticLab.com. Props to them for providing a great tutorial!