The majority of sinks that you’ve probably seen just fit into the top of a kitchen worktop (inset sinks) and slide into position. Inset sinks are pretty popular with laminate worktops but undermount sinks are installed differently and cannot be used with laminate worktops!
How does an undermount sink attach to a worktop?
Undermount sinks, as the name suggests, are positioned underneath a solid surface worktop and butted up to the bottom of it. To keep the sink in position, it is usually glued or if it’s a pretty big sink then a combination of glue and the supplied support brackets will be used, as shown in the images below.
Undermount sinks & worktops
Now, as mentioned above, you cannot use a laminate worktop with an undermount sink. This is because once laminate worktops have had the sink hole cut out, the MDF inners become exposed and water exposure straight onto this would, over time, ruin the worktop.
If you are opting for an undermount sink then you will need a solid surface worktop like quartz, granite or even wood, so that any water splashes will run straight back off the edges around the sink back into the bowl.
Although a solid wood worktop can be used with an undermount sink, please remember that the wood does need to be oiled and finished correctly, otherwise water will cause the wood to rot and bend.
If your order a granite/quartz worktop from us, the people that come to install the worktop will also put the sink into position and glue it for you but your kitchen fitter will need to connect the water and waste pipes etc., so that the sink becomes functional.
What types of materials are used for an undermount sink?
The most common types of undermount sinks that are used in domestic kitchens are:
Composite (granite or quartz)
Draining boards & drainer grooves
A common question asked about undermount sinks is that these types of sinks don’t have a draining board. Well, that is correct but if you are opting for a granite or quartz worktop then you can have some drainer grooves cut into your worktop! See the example below.
Here is a nice picture of an undermount sink, just loved the angle, almost like a spider has just crawled out of the plug hole and took the picture:-)
A common question asked regarding to wooden worktops is “with a wooden worktop and undermount sink, how do I get the drainer grooves into the wooden worktop that I have seen on so many pictures?”
Well the simple answer is that the drainer grooves will have to be created by your kitchen fitter with a tool called a router.
Free Online Kitchen Planner
Download our mobile app
Looking for some kitchen inspiration? Take a look at some of our real customer kitchens, video reviews as well as advice in our mobile app. We’ll also keep you up to date with any new ranges and offers that we have available.
Up to 50% off competitor kitchen prices
At DIY Kitchens, not only do you get a quality rigid built kitchen but you also get it at a fabulous price too! Price your kitchen up on our site and you could see savings of up to 50% off other kitchen quotes that you’ve had.
Take a look at our kitchen price comparison page here.
Real customer kitchens
Get some inspiration for designing your own new kitchen with over 3,000 pictures of our customers’ kitchens that they ordered from us.
Hi can you supply or let me know the supplier of the metal under mount sink support bars in the picture at the top of this page (the sink with the big red label on it)?
Hi Gary, this is an image of a sink that was in our showroom a long time ago and we have no details on it i’m afraid. You can create your own support on site if needed, you should be able to get these kind of supports from most hardware stores.
Hi. My current sink is dropping away from granite. Is it possible to install an undercount sink without taking the granite worktop up?
Hi, an undermount sink is either glued or has a supporting structure below it as well. You should be able to fix one of these into position without having to remove the granite.
Can I use a 600mm inset sink in the 700mm double Highline base unit? It’s for a utility so I don’t need a draining board.
Hi, an inset sink sits on top of the worktop. The base of the sink and pipes/plumbing below, would fit inside the 700mm wide unit. A standard 700mm wide base unit does not have a lowered back panel though, like the actual sink units have, to allow for pipes & drainage to connect easily.
Hi. Can you get a ceramic double bowl undermount sink? I am struggling to find one anywhere that is not a belfast sink.
Hi, I’m afraid we do not sell them. All of our undermount sinks are currently stainless steel. We are limited to what appliances we can currently sell due to supplier issues. If you have a search on Google then you may be able to find what you are looking for.
Hi… Is an undermount sink the same as a belfast sink or is it a specific type of sink?
Hi, undermount sinks are a different sink altogether. You can see them here (Undermount Sinks | Belfast Sinks)
Hi i’ve an sbf7 sink unit and trying to see how 1.5 undermount sink fits with it.
The front stay for the doors and the face seem to be too deep and i’d need to chop out
Hi Graham, the doors or fixings should not cause any problems, as there is plenty of room in that unit. It may be worth giving our technical sales team a call on 01977 608 418, to see if they can provide some more advice on this.
Hello, we have ordered a 700mm double highline sink base unit (SBF7) and plan to have a 1.5 undermount stainless steel sink. Will there be room for our water softener (H490 D440 W205) and boiling water tap 3l tank to be installed in the cupboard?
Hi Caroline, yes no problem, the high line base unit is the unit required, as it has space for all the necessary plumbing below.
Hi , I am thinking of having a under-mount sink but should the sink be damaged at anytime in the future, how difficult would replacing a under-mount sink be in a quartz worktop and cut in drainer ?
Hi Lori, an undermount sink would be easy to remove and replace and can be done without damaging the worktop surrounding it, if done correctly. The sink would need to be removed from the sealant, if you require any assistance feel free to call the office.
I want to use my original sink and drainer with a granite stone counter top but the quote includes for drainage grooves and assumes an under counter sink.. do I need to change my sink to use a granite top?
Hi Mary, you can use your original sink and drainer, you would not be charged for drainer grooves. A lot of people that have granite worktops though, do opt for undermount sinks.
What are the maximum dimensions of an undermounted sink for a 600mm sink base unit?
Hi, if you going with an undermount sink, then the inside width of a 600mm carcase is 564mm, so width wise I would probably say 540-550mm. Depth would be irrelevant, as you generally put these into sink units with nothing below, as the plumbing and traps etc need to be installed below the sink.
Could tell me what the sinks are in your showroom in the Altino champagne gloss kitchen Display? Also, what is the minimum unit size that 2 sinks can be placed into, side by side?
The sinks are Silestone Integrity Sinks (https://www.silestone.co.uk/integrity-sinks/). The ones in our showroom are £600 plus vat each, plus the cost of an undermount worktop cutout, which would be included in the solid stone calculator online. The minimum size base unit for this configuration is a 1000 wide double sink unit
Would you be able to confirm what clearances we need round an under-mounted sink and tap hole for a quartz worktop at both the front and back of the cut vout?
Hi, I would advise you to contact Natural Stone Surfaces, as they will be able to provide this sort of specific info as it will differ on different strength materials. Their number is 01298 811040
What is the best adhesive to use on undermount sinks?
Hi, we have spoken with our solid stone supplier and they have said they use low module silicone when fitting the undermount sinks.
Good evening, is it possible to use an undermount with the new compact laminate worktops that are emerging on the market? These are waterproof, unlike traditional laminate. And finally can you use undermounts with corner kitchen cabinets you make?
Hi, as these are not worktops we supply or will be supplying as far as I’m aware, this is not something we know about. It would be best to contact the manufacturer of the worktop.