First, collect 1 million pennies. The Philadelphia Mint makes 8 million of them every shift, so you’d think it would be simple to buy a certain amount of brand-new matching coins. But that’s not how it works. You have to get them in mixed $25 boxes from local banks, a few here and a few there. Then someone has to spend a lot of time tearing open the rolls.
Assemble the pennies into temporary foot-square “tiles” by placing a handful of coins on a lipped plywood form and shaking it gently until they’re all lying flat and the surface is completely covered. Complete each tile by sticking a square of adhesive plastic carpet protector — a material familiar to most remodelers — to the exposed surface. Carefully turn the form over onto a stack of previously prepared tiles, separating the layers with sheets of waxed paper.
Spread a thin layer of Latapoxy adhesive on a section of the prepared plywood subfloor. It should be thick enough to make the pennies stick securely to the floor, but not so thick it smears their exposed faces. Working fast, turn a “tile” of pennies onto the epoxy and press it into place. Once the resin has cured, peel off the plastic film. Repeat several thousand times.
Grout the pennies with clear Rock-Kote epoxy. Wear kneepads.