Furniture, Wood and Cabinetry Finishing - weight of tile countertop?

First time posting here - did some searching and couldn't find any specifics on this question (sorry if this has been answered before)

I've had a kitchen island/bar project in my head for about a week now, and I want to make sure the shortcuts I'm planning won't end up costing me more in the end : )

Basically the plan is to use plain old shelving units from your friendly big-box retailer (.5" particle board all around). I'll reinforce the backs of them with .5" plywood, and get additional screws (or L brackets) into the shelving joints where you would usually have just dowels. The arrangement would be 2 of the shelving units back to back, then another one with it's back to the side of those 2, then drill and glue them all together.

My question is this - if I take 2 5'x3' sheets of plywood and lay tile on top, would my reinforced particleboard base withstand the weight of the top? I've thought of just using a regular laminate top (there are nice ones for cheap) but if this would work, then I'd like the opportunity to get some "low risk" experience with tiling.

thanks in advance all!
jm

ps - if nothing else, I see that you have a section for DIY project failures that could use some cautionary tales :p

should not be too much of a problem, the particle board is pretty good in compressive loads (which this is) shear load like in shelving not so good. A box of 3/8" granite tile (10 pieces) is about 60 -65 pounds so about 6 pounds per sq ft...ceramic comes in about 60% of that...so your total tile weigh might be 50 pounds of so if you use ceramic..add abit for backer and thin set...and your should easy be under 100 pound over the 15 sq ft...