We have a spot in our laminated counter top where a cutting board melted and tore out a chunk of laminate. I would like to rout out a rectangle and inlay tile in the countertop as an area to place hot pans etc. I plan on routing out the area using a template, pilot bushing, and a fluted router bit. Then use thinset or mastic to provide a bed for the tile and to water proof the exposed particle board. I also plan to reinforce underneath the countertop with plywood in case the thinner particleboard can't hold the weight.
Has anyone done anything like this, and are there pitfalls I should be aware of.