Concrete Arts I don't know what a banjo top is?, are you referring to the ring around the toilet? If you did this in concrete you would have to be a minimum of about 3/4" and it would be heavy. Tom

gol43de If the toilet is right next to the vanity.sink, a "Banjo" top extends the vanity countertop about eight inches along the entire length of the wall behind and above the toilet. so the countertop has a long extension piece over the toilet. This allows you to put some of your toiletries and/or towels along an extra piece of countertop.