We have used the acrylic for many applications, on a few stairs, awnings, guardrails, etc. It is a wonderful, easy to use and relatively maintenance free material.

For stairs we use 1" clear acrylic sanded with 60-80 grit on a random orbit sander, rougher is better and faster. As in the stair shown in the picture you need a riser to ad stiffness. We dado a 3/8"x3"8" groove in the bottom of the tread, and a 3/8" x5/8" tongue on the riser, giving a reveal, we use clear silicone to eliminate any squeaking. One needs to have a sensibility about the spanning ability of the acrylic.

We buy the acrylic form a local wholesale plastic supplier, Sabic Polymers, which is a national co. Try to avoid small local plastic companies, they can be very expensive. Our supplier cuts to size, we add the dados and holes.

We find the acrylic to be a less expensive and more comfortable surface to walk on, it is "softer" than glass, easier to work with, easy to clean, etc.

Good luck.

Feel free to contact me directly if you want more info.

jim@zackdevito.com