How to Install a Pre-formed Countertop
1. Not sanding counter tops to the contours of the wall,
2. Not applying the finish surface accurately,
3. Not cutting the sink opening to the proper dimension,
4. Scratching the countertop over the course of the installation,
5. Puncturing the counter top with screws while fastening it to the base units.
Preformed counter tops are available only in standard sizes so you'll generally purchase one a little longer than you need and cut it to length. I suggest purchasing it where they will cut it for you. Cutting through the backsplash is difficult and can be costly if you make a mistake.
1. To measure for the size counter you will need, add the counter overhang (usually between 3/4 and 1 inch in front and on open ends) and add it to the dimensions of your cabinet.
2. If an end splash is to be included, subtract 3/4 inch from the length of the counter top on that side. Plan your cut for an end which will have an end cap or end splash. Cut the excess off with a handsaw; but first, mark the cut line with some masking tape to protect against chipping. Smooth the edges of the cut with a file or sandpaper
3. The end splash will be screwed directly onto the edge of the counter top or into wood batons previously attached to the edge. Apply silicone sealant to all surfaces to be joined and hold the end splash in place with C-clamps while driving in the screws.
4. An end cap is a pre-shaped strip of matching laminate which will be glued to the end of the counter top.
5. U- and L-shaped counter tops will need to be ordered mitered or cut to order as it is difficult to accurately miter these sections at home. These pre-mitered sections should have small slots for draw bolts cut into the bottom edges. Again, coat the edges with silicone sealant before aligning the edges and tightening the bolts.
6. Fasten the adjoining backsplashes together with wood screws.
7. As with the cabinets, counter tops rarely fit perfectly against the back or side walls. Often, they come with a scribing strip that can be trimmed to the exact contours of your irregular walls. Scribing simply involves running a strip of masking tape along the edge to be scribed then positioning the counter top. Set the points of a pencil compass to the width of the widest gap between the counter top and the wall. Run the compass along the wall and the irregularities will be pencil marked on the tape. Now you can plane or sand down to the line so the counter top will rest flush against the wall.
8. Once your contours are correct, position the counter top on the cabinet base. Check that all is level and shim where needed. Check also that drawers and doors may be opened freely.
9. Fasten down the counter top by running screws up from below through the top frame and corners. If there are no corner brackets, install them on the base units. This will allow you to install the counter top easily. Again, self-drilling bugle head screws are great for this job. Round head screws work best here because they will not be seen, so do not have to be counter sunk and they bear more weight in this position. Use screws that will be long enough to reach 1/2 inch into the counter core.