Worktop thickness is only an issue because worktops are available in various thicknesses.
- Laminate worktops are generally 38 – 40mm thick.
- Wooden worktops are generally 28 or 38mm thick, but can be thicker – up to 60 or even 80mm
- Granite worktops are generally 30mm thick. Thicker stone is sometimes available but is too heavy for most units.
- Quartz worktops are generally fitted at 30mm or 20mm thickness. Some manufacturers make 13mm thickness.
- Dekton® is currently manufactured for worktop use at 20mm thickness.
Over recent years, 20mm thick worktops have become increasingly popular. Occasionally companies fit natural stone worktops at this thickness, as a cost saving, but we do not recommend this. However, with the higher tensile strength of engineered stones (quartz), and with Dekton® only being produced at 20mm max thickness, thinner profiles have grown in popularity.
Contemporary kitchens lend themselves to a slim, stripped-down look. As a result we have found ourselves fitting more and more 20mm worktops. This article isn’t about the looks, but the practicalities – the issues that arise with some appliances from having thinner worktops.
A 20mm thick quartz worktop on handleless units in Horsham, West Sussex
Upgrading a kitchen by keeping the units but replacing the existing laminate or wood worktops with granite or quartz can raise thickness issues connected with the tiling and general finish of the kitchen. These have been dealt with separately here. This article looks at issues that can as easily arise in a new kitchen, and all the more so with the thinner worktops – 20mm or less.
Of course, kitchens are three dimensional This article deals with thickness… more general information on cutout sizes and clearances to front back and sides of cutouts can be found here.
Hobs and Your Worktop Thickness
For a sit-on hob, you need to make sure that there is sufficient clearance below the hob – it can be an issue if you have a hob over an oven. This is essential to maintain sufficient ventilation, and it is potentially dangerous to ignore this. Be careful: some hobs/oven combinations make the assumption that the worktop is at least 30mm to maintain this clearance – you need to check carefully.
To check: If you look at the installation instruction manual for the hob, you will see the minimum clearance required for the hob. In the example pictured below you will see that the hob is 51mm deep (diagram B), but that the minimum distance to any appliance below is 56mm. You should then look at the physical dimensions of whatever is below to make sure that this will be the case if the worktop is only 20mm thick.
Diagram of hob clearances from the Neff website
Sinks and Your Worktop Thickness
Contemporary topmounted sink in Silestone quartz worktop
If you have an undermounted sink, a thinner worktop will make no difference (the top of the sink will be sealed to the bottom of the stone).
We have occasionally, however, experienced some problems with sit-on (topmounted) sinks where the draining board runs over another cabinet. For this kind of sink, you need to make sure that the thickness of the draining board, and the depth of any retaining clips, can be accommodated in the reduced overall space with the thinner top.
Just as an example, one topmounted sink we have come across that may not be compatible even with a 30mm thick worktop is the Howdens Ceramic Single Bowl. The sink has a very deep flange. On a 1000mm base unit with no appliances beneath the ceramic body just hangs down with no problems, but on smaller units, or over appliances, there isn’t the clearance, and either the worktop or the sink needs to be changed.
Given that we often fit on Howdens units, and that few people expect issues with a 30mm worktop, it isn’t surprising that there are occasional disappointments when we come to template. You can see the technical specs for this sink with a comment on worktop thickness sink here. This model has a one-and-a-half bowl sister which has the same issue. They are fine products, but not compatible with quartz or granite worktops in most kitchens.
Lamona Single Bowl Ceramic Topmount
The Lamona sink showing deep flange – too much for a 30mm worktop