Granite Countertop Cutting & Seaming

Place a straightedge on the granite countertop where you need to cut. Mark a cutting guideline onto the counter with a piece of chalk, using the straightedge to keep the chalk line straight across the surface of the counter.

Cover the chalk line with a strip of clear masking tape to prevent any chipping from the saw’s teeth plunging into the granite surface.

Use a skill saw with a diamond blade and a vacuum hose to cut the countertop. The blade will cut through the stone without warping from the heat, while the vacuum will remove the dust created from making your cut.

Place the saw on the edge of the granite, aligning the blade of the saw with the chalked line. Turn on the vacuum, and then trigger the saw blade. Push the blade against the countertop, cutting through the granite along the drawn line to the end of the counter. Release the trigger to stop the rotation of the blade.

Repeat the cutting process for the second half of the counter, if necessary for creating the seam. Smooth the cut edges of the countertops with a power sander and 100-grit sandpaper, and then use a tack cloth to wipe off any residue.

Place the granite countertop slabs onto the cabinets. Push the two slabs together to ensure a smooth tight fit. If there are any gaps or irregularities preventing the fit of the two slabs, use a power sander on the edges of the slabs until they fit together with no visible spaces between the surfaces. Again wipe the granite clean with the tack cloth. Pull the slabs apart, leaving a gap of about 1/8-inch between them.

Place masking tape on the surface of the slabs when they meet, lining the edges. The tape will prevent the adhesive used to seam the two from spreading.

Place two suction cups each on top the edges of the countertop slabs. The cups should be positioned right across from the corresponding cup on the other slab, with two cups placed onto each slab. Attach a turnbuckle to each cup to connect it with the opposing cup on the other slab.

Mix a batch of two-part epoxy adhesive in a cup, using the mixing ratio provided by the adhesive's manufacturer. Stir the two parts together thoroughly, using a small wooden craft stick. While mixing the material, add tint to the epoxy that matches the color of the granite until you have an epoxy the same color as your countertop slabs.

Spread the epoxy to both cut edges of the slabs with the craft stick, building up a moderate layer of the adhesive. Move the two slabs together using the turnbuckles on the suction cups until they are butted tightly.

Scrape a putty knife across the top of the seam to level the adhesive. Let the epoxy dry for about two hours, and then remove the suction cups and masking tape.