I found a photo of a similar mosaic on the internet and wanted to reproduce it on our front patio. I pulled up our patio bricks 16' x20' and had a man pour concrete. I then marked the center point and used a circular protractor to mark every 18 degrees. To do that, I tied a string to the protractor and traced the string at each 18 degree interval. I then cut out a petal pattern from poster board and began tracing and then color coding the project. I began by laying out the tile and adhereing it with construction adhesive for concrete and tile. I quickly discovered I was short in tile. I'm over budget by double--it's my first one and I didn't really know how to estimate the cost. I'm still in the process of laying tile and will update you when it is complete.