Soapstone is a malleable stone with exceptional density that feels to the touch like a dry bar of soap. It makes a great, elegant countertop material.
To cut and install custom-cut soapstone for any countertops, backsplashes or islands, it is critical to first measure precisely.
Measure each part of the countertop area, taking into account and eliminating irregularities in the back wall. Include a 1-1/4” overhang at the front edge of the countertops. Before you begin cutting any stone, double-check those measurements.
Use a level and nylon string to make sure your cabinets are plumb and square.
Next, build a template (Image 1) for each piece of stone that needs to be cut. This is especially helpful for those pieces that have unusual shapes and are not strictly rectangular. Make the template using 3/8” or 1/2” luan plywood. It's best to make the template fit the cabinet bases perfectly, nailing and gluing the pieces together and then placing the template right on the counter bases to get an exact measurement.
When the template is ready, lay it directly on the stone and hold the template in place with clamps. Trace round the with a pen mark that you can see when cutting (Image 2).
Cut the stone using a circular saw with a dry cutting diamond blade. Set up a straight edge to guide you as you use the saw. Cut along the marked lines with a steady hand (Image 1).
Once the piece is cut, sand it with 36-grit sandpaper, using a belt sander with a vacuum attachment (Image 2). You must wear a mask during this process.
Once the piece is cut and sanded, dry set it in place and check that it fits exactly (Image 3). Make sure the overhang is 1-1/4”.
The next step is to measure the island (Image 1). A template is not needed for these pieces of stone because they are rectangular. The island countertop will be made with three separate pieces of soapstone.
To create eating areas around the island, add an overhang of 12 inches on one side and 8 inches on the other. The other two sides maintain a 1-1/4” overhang. The whole island for this project measures 37 inches from front to back and 70 inches from side to side.
Transfer the measurements of the island to the stone. Because of the size, the island counter is made of three equal pieces that will be joined together. Each section measures 37 inches by 23-1/3”. Cut each piece for the island (as above).
Because these pieces will be joined together, the edges have to be treated in a special way. Use a router with a diamond bit along the seam edges to smooth them out and create an edge that is 90 degrees to the surface (Image 2). Work the router along the edges in a back and forth motion and apply a steady, even pressure. Use a straight edge to guide you. This treatment will ensure a tight seam that will almost disappear when you join the pieces together.
Dry-set the three pieces on the island and look at the seams. You want the island to appear seamless. Look at the veins and see how they move across the seams. By turning a stone around and positioning it differently, you can get the seams to seemingly disappear. Once you are satisfied with the orientation of the stones, set them in place with the correct overhang measurements and clamp them into place.
The next step is to glue the soapstone pieces into place. You need to glue the seams together with a fast-drying epoxy and then glue the pieces to the cabinet below with an adhesive caulk. To minimize clean up of the epoxy, tape the edges of the seams with painter's tape.
Begin with an end piece. Unclamp the stone and place the soapstone on blocks of foam. Place a bead of adhesive caulk on the edge of the cabinet in a smooth thin line. Set the stone back into place. Line it up with the stone next to it, which should be set exactly in place.
Next, move the center stone onto the foam blocks. Apply caulking to the cabinets as before. Apply a quick-drying epoxy to the seams of the stone. Set the middle section back into place and gently squeeze the epoxy together against the first stone. Repeat the process for the last stone. Firmly press the pieces together. Let the epoxy and adhesive dry.
Once the epoxies and adhesives are dry, use a belt sander to sand off any excess epoxy and smooth the entire stone. Use a belt sander with 36-grit sand paper. Attach a vacuum to the sander to collect the dust, but also wear a good mask. Apply an even pressure, just enough to smooth the surface (Image 1).
To round the corners of the island, use a roll of tape as a template and trace the round edge to make a soft, round corner. Repeat on each corner of the island. Then, using the belt sander, sand down the corner to the round corner mark. Twist your body, and gently rock back and forth to round the edge (Image 2).
With the corners rounded, it's time to treat the edges of the island. Use a fine-cut file and a piece of 80-grit sand paper. File the edge firmly (Image 3), then sand it gently (Image 4).
Repeat all the way around the island.
Next, we return to the kitchen counter. The two pieces on either side of the stove in this project are rectangular, so no templates are needed. Measure the dimensions then transfer them directly to the stone for cutting. Remember to account for the 1-1/4” overhang.
Cut the stones as before with a circular saw and sand them with a belt sander. Dry set the pieces to make sure they fit correctly and then glue them in place with the adhesive caulking.
Make templates for the remaining pieces around the sink (Image 1). With those templates cut, tranfer to the soapstone, mark, cut, sand and set in place, using the adhesive caulk and epoxy to glue them in place.
Remember to tape the seams to minimize cleanup (Image 2).
Push the pieces together and press firmly against the wall to set them in place.
You might decide to add a window ledge made of soapstone above the sink. Measure, cut and sand just as you did the other pieces. Use shims to hold it in place. You will glue it when you install the backsplash behind the sink.
If you have a faucet to install into the soapstone, measure carefully for the hole or holes that need to be cut. There may be variations in installation procedures, depending on the brand and model of faucet you select. It's important to read and follow the manufacturer's instructions that come with the faucet you've chosen.
Sand the seams on the faucet deck with a random orbit sander (Image 1), which prevents making a circular impression on the stone. Hook the sander up to a vacuum. Sanding the seams helps to hide them.
Once you've decided on the location of the faucet, dry fit it and make sure you like its position and that it functions well. Drill a circular hole with a regular hole saw. Install the faucet and connect it to the plumbing.
File the edges of the countertop as you did with the island. Use a fine-cut file and 80-grit sandpaper. If you think it needs more sanding to eliminate file marks, use a finer grit sandpaper and sand away.
To add a backsplash against the wall around the perimeter of the counter, make sure the height matches the molding that is already in place. In this project the masons added a large piece directly behind the sink that reaches the window ledge (Image 1).
Measure and cut the pieces for the backsplash. Dry set them to make sure they fit.
Tape the seams and butter the edges with epoxy. Add adhesive caulk to the wall and the bottom edge. Use a wet rag to smooth the caulking line (Image 2).
With all the pieces of soapstone glued and sanded, the final step is to treat the surface of the stone with mineral oil. Pour the oil on the countertops and spread it with a rag.
You don't need to work it in. When the exposed areas are covered, turning from light gray to black, come back with a dry cloth and wipe off the excess oil. The oil protects the surface and helps prevent spills from staining.
You are now ready to enjoy your soapstone kitchen.