A few pointers to help you steer through the maze of kitchen sink choice
Under-mounted v Top-mounted Sinks

Undermounted sinks are fitted below the worktop, with a polished hole cut in the stone forming the “entry” to your sink. Tapholes must be cut into the stone, and many people also have drainage grooves ground and polished into the top surface.

Topmounted sinks sit on top of the worktop, with a flange or lip sealed down onto the stone. Because the hole through the stone is not visible, it doesn’t need to be polished. Tapholes are normally in the “tray” of the sink itself and do not need separate cuts in the stone. the drainage area is integral to the sink and cannot be cut into the stone.

More definitions (including of other sink types) can be seen in our glossary, here.

A regular question we here is which of these two basic types is better. There is no one right answer; issues of taste and lifestyle will make customers lean more one way or another.


A one-and-a-half-bowl undermount sink – case study


A modern topmounted sink

Under-mounted sinks:

Undermounted sinks are still the most favoured option when it comes to choosing sinks for granite worktops. They look incredibly stylish and uncluttered as there is nothing sitting on the surface of the granite. If the majority of your washing up goes in the dishwasher then under-mount is a great choice for you and everyone will know that you have “top of the range” worktops as you cannot have under-mounted sinks with “laminate”or “formica”  worktops! Some of our customers choose to have two larger under-mounted sinks so that they can use one as a drainer rather than having washing-up draining on the actual worktop. (Please check that you have the width of cabinet necessary to accommodate the sinks.)

It needs to be said that sit-on sinks probably win in terms of absolute practicality when it comes to water handling- a drainer attached to a sit on sink will drain better than the grooves that are cut into the granite work-surface to go with an under-mounted sink. To be absolutely blunt, drainage grooves cut into polished stone at 30mm thick or less cannot slope enough to really drain. They are aesthetically pleasing – they look right! – and the stop hot glasses full of expanding air hovercrafting off the edge of the worktop, but they are not great drainers.

Size of sink

Blanco Supreme 533–U in Tortoiseshell granite shown here with splayed grooves. This sink has been replaced in our stock by the 1810 Company Etroduo shown in the first section of the article here.

One of the main factors when determining the size of sink is the size of cabinet it fits into. We hold stock of small separate sinks in a one-and-a-half-format to be fitted into a 600mm cabinet with a strip of stone between them.

However, more economical than the two separate sinks would be a one-and-a-half-bowl single unit, such as the Etroduo.

Occasionally people choose a sink that is too big across the worktop from front to back. To maintain the strength around a sink cut out, we need a minimum of 90mm of granite or 110mm if there is a tap hole to cut out. For example: if the finished width of the worktops from front to back is going to be 610mm and you want the tap to go in the centre behind, then the sink cut out can only be 410mm from front to back. (a 420mm sink with 5mm overhang of granite all round is ok)

If the sink is too large we may be forced to have a larger overhang into the bowl or locate the tap off to the side of the sink at an angle.

Please note that granite up-stands/splash-back may also mean that it is necessary to put the tap to one side rather than directly behind the sink as they swallow some space at the back.

Topmounted sinks:

It used to be the case that sit on sinks were all much of a muchness but in recent years there have been many advances in design and materials leading to a huge range of choice for the consumer. There are sit on sinks with all sorts of accessories, sliding chopping boards, vegetable drainers etc with prices anything from £70.00 to £700.00 and even more. (Please email or call us for a comparison price if you have seen a particular sink you like elsewhere)

Sinks marketed as under-mounted or sit on:

Some sink manufacturers sell sinks that are described as being suitable for under-mount use or sit on. In practice these are generally not the ideal choice as they often have a deeper flange that is not as aesthetically pleasing when fitted and quite often there is also no room for the tap hole. If you are thinking of purchasing a screwfix sink like this or any other make like this please contact our sales team to discuss its individual suitability for your particular installation of granite worktops.