We are currently fitting new kitchen worktops but the walls are not straight (we have a very old house) and so there is a small gap at some points between the wall and the worktop. We were not planning on tiling the walls. What is the best thing to do here to give a good finish?
It depends on the gap size. Anything up to about 4mm can be sealed with a silicone sealant. If the gaps are bigger you will need to scribe the worktop to the wall.
To do this, position the worktop hard against the wall but keeping it parallel with the base units underneath. Take a pencil and place it so lead is sitting on the back edge of the worktop at the point where the largest gap is. pack out to the pencil from the wall with some thick card or wood and secure to the pencil. Next run the pencil along the worktop along the whole length which will draw the line of the wall on the worktop. Now using a jig-saw. cut along that line and discard the waste. The top should fit snug now.
What you are doing is transferring the shape of the wall onto the worktop (scribing)
Top-tip = before you draw the line on the top, stick a piece of 2" masking tape along the length. This will enable you to see the pencil mark easily when cutting.
Use a new down cutting jigsaw blade. This will ensure that the formica surface does not chip out as the blade moves up thus leaving a cleaner finish.
If your are not tiling or at the very least going to seal around the edge with silicone then any part of the top that you cut through on the back edge needs to be sealed with silicone or P.V.A. This is to prevent any swelling of the top from water ingress as you wash or wipe down.
It may be a good idea to mark the laminate with a stanley knife and a straight edge (as long as the scribing is straight enough)
This iwll prevent cracks or splits on your worktop when you cut with the jigsaw.