Top vs Under Mount Sink
Topmount sinks are often referred to as drop-in or self-rimming sinks. They are very easy to install – you just cut a hole smaller than the outer dimension of the sink but bigger than the inner dimension. For that reason, some granite shops wish that you pick another topmount sink when you switch from laminated wood to granite! The drawback for top mounted sinks is that it is easy to have black dirt or soot built up around and underneath the edges – if you happen to have taken off a top mounted sink, you know what we are talking about here. It needs periodic caulking around the edges to keep this from happening.
Because the top edges of a drop-in sink cover and seal the entire sink cut-out, this type of sinks is ideal for countertops made with laminated wood or porcelain/ceramic tiles.
Undermount sinks are installed under the countertop, giving you a sleek and seamless look and making it easy to clean and maintain. Undermount sinks are known for being located underneath the countertop. For this reason, you should almost never use it if your countertop is made of laminated wood – as water would eventually penetrate the corners or the damaged areas of the counter edges.
However, sinks can be under mounted with these materials: (1) all stones – whether natural or engineered stones, (2) concrete, and (3) cultured marble or other solid surface materials that can withstand prolonged water contact.
Certain skills are required to mount these under-counter sinks to ensure the sinks hold to the counter fast and are sealed properly between the gaps.