6. Sink Mounting Positions

Outline:
Top mount
Under mount
Recessed under mount
Flush mount
Butler sink

Sink Reveal
Negative reveal
Flush reveal
Positive reveal

Welded in
Steel or Corian

Sink position and mounting

Top mounting

The most functional sink position is top mounting. Often top mounted sinks are single or double bowls which have a drainer board. When dishes are placed on the drainer the water runs off into the sink bowl. It is the cheapest method of mounting a sink as the cutout in the bench material is rough and hidden and therefore does not need polishing. The edges of the cutout are hidden and not exposed to knocks and chips.

Wiping the bench around a top mount sink can be problematic if the edge of the sink is square and thick. Dirt and grim can be hard to wipe around this kind of edge. Better topmount sinks have a “laser” edge which means the steel is flattened and thin at the edge making wiping easy from the bench over the edge into the bowl.

Summary:

1. Top mount bowls are the most functional.
2. They generally have a drainer board.
3. They generally are large visually because of the drainer board
4. Topmounting is the cheapest installation method.
5. Topmounting protects the edges of stone cutout from chipping since the raw cutout is under the sink material and not exposed.
6. Laser or easy-wipe edges help to minimise the trapping of dirt at the edges of the sink.
7. Cheap sinks and sinks pressed from 0.9mm steel can be top mounted without problems because the clips pull the sink edge down onto the benchtop.

Under mounting

In this installation, the top of the sink flange is mounted on the underside of the bench material. Usually undermount sinks are without a drainer board. Sinks with drainer board can be under mounted, but in my opinion this is an unnecessary cost without much benefit. The major benefit of undermounting is losing the drainer board so that the aesthetic is seeing little sink and seeing lots of benchtop.
Summary

1. Undermounted sinks generally do not have a drainer board.
2. They can be single or double bowl.
3. Installation costs more because the edges of the cutout must be polished.
4. Extra care must be taken not to strike the edges of the stone as chipping occurs on the edges over time.
5. A mobile drainer tray can be used to drain water from stacked dishes into the bowl.
6. A tea towel can be placed on the benchtop under dishes to trap water which is not able to drain into the bowl.
7. A good quality sink is important for under mounting. The issue is straightness or flatness of the edges. No wavy edges please. A sink made from 1.0mm steel should be the entry level.

Rebated under mounting

If the benchtop thickness is more than 20mm then a rebate can be cut from the underside of the stone so that the sink sits down only partly, rather than mounted under the full thickness of the benchtop.

Flush mounting

This is the most difficult technique and the dearest. A flat edge under mount style sink with a very flat good quality edge is required. Very precise stone cutting is done which routers down the thickness of the sink edge, so that the edge of the sink sits flush with the benchtop material. The resulting aesthetic is very attractive.

Butler sinks

Butler sinks are undermounted and in addition the front edge of the stone is removed so that the sink front edge is visible. The sink has a front face of polished material which is highly visible.

Note that the front edge and face of the butler sink can be either

1. flush with the front edge of the benchtop or
2. flush with the front of the cabinet door fronts. In this case the front edge of the sink will be 10-20mm negative to the benchtop edge.

Welded in sinks are flush mounted
A special case of flush mounting is achieved when stainless steel sinks are welded into a stainless steel benchtop. Very hygienic, no nooks and crannies, no silicon seals, just perfect invisible joins between sink and bench.

Solid surface benchtops such as Corian and acrylic materials can also have “welded” in sinks. These sinks are specially constructed for “welding” into solid surface benchtops. The sink is constructed fully or partially of the same acrylic material and glued and polished into place, resulting in a perfectly seamless appearance. Very attractive.

Sink Reveal
Sink reveal is pertinent to undermounted sink positions. The reveal refers to the amount of sink top lip will be visible after mounting.

Positive Reveal
Positive reveal is when the cutout for the sink is larger than the size of the sink bowl. Therefore some of the lip is visible – not completely covered by benchtop material. If you have sink accessories like inset colander or chopping board, beware, they might not fit after undermounting – depending on the width of the accessories. They could be problematic either too wide or too narrow. If there are sink accessories and the sink is to be undermounted then the accessories must be presented to the benchtop fabricator to make sure they fit after the sink is fitted.

Flush Reveal
Flush reveal is when thecutout for the sink is exactly the same size as the sink bowl. The edge of the sink bowl lines up exactly with the edge of the benchtop.
Benchtop fabricators don’t like this kind of reveal as it is difficult to achieve and there is no room for error. Sink accessories should have no problems with flush reveal.

Negative Reveal
Negative reveal is when the cutout for the sink is smaller than the actual bowl size by a few mm on each side. The edge of the bowl is negative to the edge of the benchtop material. Fabricators like this kind of reveal as it gives them some room for error on the cutout dimensions. Sink accessories are likely not to fit with this reveal, or may need to be trimmed in the case of wood chopping boards. Make sure the benchtop fabricator is aware of any sink accessories to be sure they fit after sink undermounting.