How to replace a worktop
This task may be tricky so will suit you if you're experienced in DIY, or simply love a challenge.
Before you get started on any of our 'how to' guides, please take a moment to read through our DIY safety tips.
Tools: plane, steel rule, screwdrivers, jigsaw, cordless drill, flatwood drill bit set, spirit level, sealant, craft knife, fine file
1. Measuring up
First things first - it's important to measure up accurately before you get cracking! Obviously you only have to measure the old worktop if you're just replacing it with one that's the same shape. If you're changing the shape and size of the worktop, remember that you'll need to maintain an even overhang along the front edge of the kitchen cabinets. Aim for a 10mm-20mm overhang but add on some extra to play with. Here's an example: buy a 600mm worktop to overhang 560mm-deep cabinets. This extra 40mm could come in handy if you need to trim a bit off the worktop's back edge so it fits flush against your wall. Also allow 25mm for overhang at either end of your new worktop.
2. Scribing the worktop to fit
The wall you're fitting your worktop against is likely to be slightly uneven so there will be gaps to fill. To do this you trim or 'scribe' the worktop. This is how you scribe:
Position your worktop with its back edge against the wall. Make sure the overhang at the front of the cabinets is exactly the same all the way along.
Measure the largest gap between the wall and the back of the worktop.
Cut a small block of wood exactly the width of this gap. This is called a 'scribing' block (fig. 1).
Stick a strip of masking tape along the entire length of the back edge of the worktop.
Starting at one end of the worktop, run the scribing block against the wall and use a pencil to mark a line along the masking tape (fig. 1).
This mark is a copy of the shape of your wall and acts as the guide line for trimming.
Cut along this line with a jigsaw. Where only small amounts need removing, use a sander or plane instead.
You can now replace the worktop and check it fits. Make sure the front overhang front is still even all the way along.
If your worktop is too deep, trim the depth at the same time as scribing. Measure up for your scribing block, then deduct this measurement from the amount you need to trim off the depth of the worktop. Now cut your scribing block this width and proceed as before.
3. Cutting the worktop length
When you cut your worktop to the correct length, allow for a 25mm overhang at each end.
To cut a straight line without damaging the surface, first mark the line in pencil. Cover the pencil line with masking tape - you should still be able to see the line through the tape. To get a straight edge, clamp a steel ruler along the pencil line and use a craft knife to score a groove down the line. Then follow the groove with a jigsaw (fig. 2).
Remove the ruler and cut along the line with a panel saw. Make sure the worktop is well supported at both sides. When you've finished, remove the masking tape and smooth off the end with a plane. Always plane away from the top surface so you don't damage it.
4. Joining lengths of worktop in a straight line
You can join lengths of worktop without the need for a joining strip. Here's how:
Cut the two pieces of worktop being joined together to the right length. Scribe them to fit if you need to (see section 2).
From underneath, secure the two worktops together with fixing plates. Mark the screw positions and drill pilot holes while applying some weight to the top of the worktops (fig. 3).
Apply wood glue to the edge of one worktop and push the two together.
Use three fixing plates to secure the join properly.
Wipe away any excess glue before it dries.
5. Using a joining strip to turn a corner
Use a joining strip to join two lengths of worktop if they have rounded edges.
If your worktops have rounded edges you'll need to use a metal joining strip to fix two lengths together when going around a corner.
First, mark on the joining strip the length of the join - use a piece of masking tape to make the mark.
With a hacksaw cut the joining strip to length. Smooth off any rough edges with a metal file.
Put some silicone sealant on the edge of one of the worktops. Push the strip into position and screw it in place (fig. 4).
Apply more sealant to the edge of the other worktop. Then butt it up against the joining strip on the first worktop.
6. Securing the worktop to your kitchen cabinets
When you fix the worktop to the kitchen cabinets, you'll need someone's help to apply pressure from above.
Attach the worktop from underneath with screws and fixing brackets.
Clamp the front edge of the worktop to the fixing rail at the front of the cabinet. Screw through the rail into the underside of the worktop.
To secure the back edge, screw fixing brackets in place while someone applies pressure from above (fig. 5).
7. Finishing the exposed edges of your worktop
For solid wood worktops, sand smooth the unfinished edges and protect them with stain-proofing oil. Follow the manufacturer's recommendations for the best sealant.
Laminated worktops usually come with finishing strips. Cut the strips to the right length and put adhesive on the strip and the edge of the worktop. Fix the strip in place and leave it to dry. You can then trim the edges flush with a craft knife. Always follow the manufacturer's instructions.
8. Cutting a recess for your sink
Most kitchen sinks are recessed into a worktop, so when you fit yours you'll need to cut an accurate hole to accommodate it.
Some appliances come with a cutter guide to help you - otherwise you'll have to draw this yourself. But don't worry, this is pretty straightforward:
To draw a guide, simply place the sink upside down in the exact position where you want it and draw an accurate pencil line tight around the edge.
When you position your kitchen sink, check that the distances at the front and back are equal and that the sink is parallel to the edges.
Next measure and mark the depth of the lip of the sink - i.e. the overlap needed for the sink to sit on the worktop to stop it falling through the hole. The manufacturer usually gives you measurements for this.
Use a ruler to mark a second line this distance in from the first pencil line. This second line marks the edge of the recess you're going to remove.
Use a 12mm flat drill bit to make a hole in each corner of the sink recess, using the inner line as your guide (fig. 6). Keep the drill upright and don't stray outside the inner line.
Using the drill holes as starting points, carefully cut around the inner line with a jigsaw. Hold the top down firmly as you cut.
Smooth off any rough edges and treat the exposed areas with a preservative primer. Check the sink fits in the recess.
9. Inserting the sink
It makes things easier if you attach the taps, tap hoses and waste pipes/overflow to the sink before you fix it in place.
If the sink comes with a seal to go between the sink and the worktop, then use it. If not, just put a silicone sealant around the edge of the sink recess.
Fit the retaining clips around the edge of the sink and lower it into the recess. Tighten the clips and wipe away excess sealant.
Now all you need to do is connect the taps and waste and check for leaks.
Kitchen worktops obviously get wet quite often so apply a flexible sanitary silicone sealant around all the joints - particularly where the worktop meets the walls and around the sink.