How To Mark Out The Sink and Hob


How to Mark Out The Sink And Hob?how to mark out the sink and hob

How to mark out the sink and hob While the worktops are in their final position? now is a good time to mark out the position for the sink and hob.

The easiest method on how to mark out the sink and hob is to place the sink upside down on top of the worktop. Make sure the drainer is on the correct side and then step back to align the sink and to make sure the bowl or bowls fit into the inside of the sink base.

Because sink manufacturers tend to make their sinks as big as possible, when a bowl and a half needs to go into a 600mm sink unit it can be very tight, so caution is needed to accurately position the sink.

With the sink in the correct position use a strip of masking tape to mark the edge of the sink on the left and right-hand side. Then check the front to back position.  Try to get the gaps equal, and then move the sink towards the front by around 5mm to allow for the tiles to run along behind the sink.

Then put a couple of pieces of masking tape along the front to make sure that if the sink is moved it can go back to the same spot.

Now place a couple of pieces of tape diagonally under each corner so that a line can be drawn around each corner before then removing the sink.

See Figure 23 in "Fit That Kitchen" - How to Mark out the sink and hob - step one

Place a fastening clip to the sink and measure the difference between the clip and the edge of the sink.  This is often 10mm, but you should check your sink.

See Figure 24 in "Fit That Kitchen" - How to Mark out for the sink and hob - step two

Measure the difference inside the line drawn off the corner and mark, in this case, 10mm.  Do that on all 4 corners and then apply masking tape along all 4 sides in a position so that the 10mm line can be drawn along the tape, effectively joining all four corners. 

The radius of the corner can be drawn freehand or something suitable to draw around can be used.  This line is the line to cut around with a jigsaw.

One further TIP on how to mark out the sink and hob is to put an additional length of tape around the outside of the original piece of tape to give the jigsaw base something to rest on, preventing the jigsaw from marking the surface of the laminate.

When it comes to cutting the sink out, drill a 13mm or bigger hole at each corner then cut the front and back lines first.  (This maintains the strength of the worktop).  Then when it comes to cutting the ends, cut the end with the shortest distance beyond the sink first. 

Make sure the worktop is supported on benches, then slide a piece of batten under the end you want to cut and clamp it in place so that when you cut the worktop it is supported once cut.

The fourth cut on the end is done in the same way so that the cut out piece is resting on both battens and can be lifted out when cutting is finished. If the battens are not put under to support the cutout piece, the remaining worktop will be damaged by the cut out falling away whilst being cut.

How to mark out the sink and hob? Other ways to use this method.

This technique can be used on hobs as well, but they are difficult to lay upside down because of the knobs, so it is best to mark them out by measurement only.

When all the cut outs have been done the exposed chipboard edge needs to be sealed to prevent, moisture penetrating.  There are several ways of achieving this. I recommend Evo stick adhesive as it is rubber based and handy as it is used to stick the laminate end strips on. You can also use silicone or paint.

Before the worktops are put back onto the units drill 5mm holes in the front rails of all of the base units so that they can be screwed up through them into the worktops to secure the worktops in place.  Fix angle brackets along the back to secure the worktop down if nothing else is provided by the kitchen manufacturer.

Make sure there is access to the worktop bolts from inside the corner units, and this often means cutting away some of the rails or solid tops in the correct place.

This can be done by measurement or by putting a piece of worktop back into place and drawing a pencil line along the joint to mark where the bolt slots are.

To enable the sink to be fitted in place usually, the front rail needs to be cut to allow the bowl to fit inside.  Be careful to not remove any more front rail than necessary to keep some strength.

The other thing is where the sink clips are positioned above the rail, holes need to be drilled to allow the clip to pass through and attach to the underside of the worktop.  This means the hole needs to be 2/3s into the open space and a 1/3 under the worktop to allow the clip to drop through and then move and fit under the sink.

See Figure 25 in "Fit That Kitchen" - View of sink clip from below

To start with gently place the sink in position. The bowls can often foul on the front rail so mark out the portion that is in the way and remove the sink. Carefully cut the front rail by the least amount to enable the sink to fit. This rail is often left weak and care needs to be taken not to damage it before it is finally secured to the worktop above.

Now replace the sink and let it rest on the clips and mark out all the clip positions where there is an obstruction to the clip going under the worktop. Remove the sink. With any clips along the front, transfer the clip position down onto the front rail and make a 5mm hole through the front rail with the drill just resting against the worktop cut-out.

Now with a suitable size hole saw which is just big enough for the clip to pass through, go underneath the rail and with the pilot drill in the previously made hole carefully drill up with the hole saw until the front rail has been drilled right through but no further. 

What this does is to allow the claw part of the clip to pass through the hole and then swing under the worktop ready to be screwed up.  See Figure ?

Where the clips are over the side of the base unit, again transfer the clip position down and then mark the width of the clip and drill a series of holes next to each other into the unit side, just under the worktop. A 5mm drill is usually suitable for this and then with the drill still turning move the drill left and right to ream away the webs between the holes to leave a slot for the clip to go into.

This same method applies to the hob as well.


Ray Brock
"The Seasoned Kitchen Fitter"


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  1. January 9th, 2010 at 23:43 | #1

    when buying a sink with clips why do they always seem to be more clip holes in the sink than clips supplied is this normal

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