A vessel can be installed sitting on the countertop (“above counter mounting) or it can be sunk down up to a third or even half of its height. Some vessels are actually a hybrid of a drop-in style sink and a vessel – i.e. they are designed to partially sit above the countertop.
For an above counter installation, you will need a hole that is large enough to accommodate the drain assembly. This is the plumbing hardware that allows the sink to drain the water. If the bottom of your vessel is flat, then the installation is straightforward. The only thing we would recommend is a bead of silicone under the sink and around the edge to prevent water on the countertop from working its way underneath the vessel. If the vessel has a rounded shape – as with most glass vessel sinks – you have two options. You can either use a vessel mounting ring (sometimes these are provided with the sink) or you will need to provide a mounting hole directly in the countertop.
Mounting rings for vessel sinks can be easily found at most home centers or online. They usually come in several finishes that you can match to your faucet and drain. A vessel mounting ring elevates the sink from the countertop and helps with the stability and seal of the sink.
Due to design considerations, a mounting ring is not always desirable. If you want to mount the vessel directly into the countertop, you will need a hole that is at least 3″ in diameter with a beveled edge in the countertop material to accommodate the shape of the bowl. You may want the hole to be more in the range of 5″ – 6″ if the vessel is larger for stability. Use clear silicone to provide cushion and stability when mounting the sink. If you want to lower the level of the sink you can simply enlarge the hole. The larger the hole, the more stability you will achieve in the installation. To experiment with the size of the hole, use a piece of cardboard. Start with a smaller size – say 3″ – and work your way up. This will give you a visual as to how far down the vessel will be relative to the counter throughout the size range that you choose. Be sure to keep the height of the faucet you have chosen in mind when making these decisions.
Whichever mounting method you use, you will want to install the drain in the vessel before installing the sink to the counter surface. Drains for vessel sinks come in two basic configurations. Does your vessel have an overflow? If so, you will need a standard drain. However, most vessel sinks do not have an overflow and will need a “vessel style drain”. Vessel drains come in many different styles and finishes. These drains do not have a “pop up” assembly. Some are referred to as “grid drains” (referring to the “grid configuration” on the top of the drain). Grid drains were designed to let the water flow out of the basin but catch larger objects from heading down the drain.
A special caution for glass vessel sinks. If you are installing a glass vessel, be sure to provide a cushion between the glass and the counter. This can simply be a bead of silicone or you may want to line the hole in your counter with a small piece of rubber material. In addition, be sure that you don’t over tighten the drain assembly. Hand tighten only and follow the manufacturer’s instructions. The breakage we see with glass vessels is usually associated with an improper installation of the drain.