How to Make Precast Kitchen Countertop Molds

Kitchen countertop molds are installed in place on top of kitchen cabinets. These molds are in the shape of the eventual finished countertop. Wet concrete can be poured into the mold and dried and finished. The do-it-yourselfer can install kitchen countertop molds in four to six hours, depending on the size and scope of the project, as well level of experience.

3/4-inch plywood
2-by-4 lumber
Felt paper
Galvanized staples
3-inch wood screws
Diamond mesh
Concrete trowel
Orbital sander
120-grit sandpaper
Concrete sealer

Instructions

- 1
  Attach 3/4-inch plywood to the top of your base cabinets. Apply construction adhesive to the top of the cabinet box, and lay precut plywood over the glue. Cut the plywood flush with the outside edge of the cabinet box.
- 2
  Attach a 2-by-4 around the top perimeter of your kitchen base cabinets. Align the 2-by-4 with the top edge of the cabinet, and attach the lumber with 3-inch screws. Overlap the 2-by-4s at the corners for added strength. This 2-by-4 forms a 1 1/2-inch overhang for the countertop.
- 3
  Attach a 2-by-6 flat along the outside of the 2-by-4, aligning the bottom side of the 2-by-6 to sit flush with the bottom of the 2-by-6. Connect these boards with 3-inch screws. Overlap the 2-by-6s at the corners, as well. The 2-by-6 should extend above the plywood base 2 inches. This lumber serves as a wood form for the concrete countertop cement.
- 4
  Cut 15-lb. felt paper to go inside of the countertop mold. Place the felt over the wooden forms, and trim the paper to fit inside the perimeter of the mold (wooden form). Attach the paper to the plywood with galvanized staples.
- 5
  Install diamond mesh wire over the top of the felt paper. Cut this wire with metal cutters to fit inside the perimeter of the countertop mold. Attach the wire to the plywood and felt with a staple gun and galvanized staples.
- 6
  Pour cement inside the precast countertop mold. Fill the cement up to the top edge of the 2-by-6 installed around the countertop. Smooth off the cement with a hand trowel. Allow the cement to dry for 24 hours.
- 7
  Remove the 2-by-6s and 2-by4s from around the perimeter of the cabinet base, leaving the dried concrete countertop. The countertop overhangs the cabinet by 1 1/2 inches, which is the thickness of the 2-by-4.
- 8
  Sand the countertop with 120-grit sand paper and an orbital sander. Round the edges off, and smooth the surface to your specifications. Wear a dust mask when sanding, to keep the dust from getting into your lungs.
- 9
  Spray on gloss concrete sealer to preserve the concrete countertop and provide a shine to the finish. Add 1 qt.of concrete sealer to an electric sprayer. Spray in even strokes across the countertop. Allow the sealer to dry for 24 to 48 hours before using the countertop.

Acrylic Countertop vs. Laminate

Corian Self Installation

Kitchens