Last summer my husband re-did out bathroom floors with new tile and it wasn't til after the fact that we realized how slippery it was when it got wet from the shower or sink. We purchased a product called Johnny Grip after his friend from work suggested it and it worked well for us. I'm not sure if it will work for tile that is outdoors in the elements all the time, but if you want to call them up and find out I'm sure their number is on the website http://www.slipperytile.com/coefficient-of-friction-tile Hope you can work this out.
P.S.- I wish I had a homemade patio!! :)

Thanks Claire44. I called their number and spoke with a customer service rep. but he seemed a little distracted at the time lol. He did say that it would work for the tile inserts on my patio so I�m hoping for the best. Now I�m just waiting for the product to get here.

Best of luck :)

I applied the product a few days ago and so far, so good. It was a little tedious having to be down on my hands and knees to coat it onto each individual tile square with a sponge, but I guess if I was working with an entire kitchen floor and a mop it would have been a bit easier! Now only time will tell if it lasts�