When installing a farmhouse sink, it doesn't go above the counter top like a drop in, and it's not glued to the under side like an under mount. It has to be installed flush with the cabinet tops so the granite or other solid surface top and be placed on top of it. The weight of some farmhouse sinks are upwards of 150 pounds if they are cast iron enamel coated. Some of the stainless steel ones such as the one in this video weigh about 30 pounds. The rear of the sink has to be supported with solid brackets and if the sink is near 100 pounds or more, I would support the front the same way I did the rear since the frame of the cabinet may sag from the weight.
