Concrete countertops may be used in kitchens and bathrooms. Their beauty and durability make them timeless and their DIY potential makes them irresistible to budget-minded and creative homeowners. Adding the beauty of recycled glass to the project is both and economical and environmentally positive choice that will create truly one-of-a-kind countertops.
Measure and sketch an accurate layout for your countertops. Transfer the sketch to a template that is the mirror image of the final form you want to create. Concrete will be poured into a mould based on the template, so be sure to be accurate in the placement of all holes and edges.
Using your template, build a mould out of the laminate board, a material which releases the dried concrete easily. The depth of the mould should be equal to the desired thickness of the countertop but must be at least 1 1/2 thick for strength. Cut mesh reinforcements just smaller than the dimensions of the countertops and set aside. Be sure to screw from the outside of the mould and cover each screw head with tape to prevent it from being clogged with concrete. Holes for faucets and drop-in sinks can be built from laminate or short lengths of PVC pipe.
Fill all edges and gaps in the mould with latex caulk, smoothing the caulk with a grout tool to create the finished edge you desire. Remember that anything in the mould will be exactly duplicated in the concrete so keep your edges consistent and watch out for drips or nicks on the laminate.
Mix high-strength concrete according to the manufacturer's directions, adding in recycled glass in place of, or in addition to, any gravel called for in the mix.
With the moulds on a flat and secure surface, pour the mixed concrete into the moulds, carefully working the concrete into all corners and around all voids to assure even coverage. Sink mesh reinforcements a third of the way down into the concrete, being sure it is not touching the bottom or sides of the mould. Scrape across the top of the concrete with a scrap of wood in a sawing motion to remove any excess.
Using a rubber mallet, rap the sides of the mould to release any air bubbles from the concrete. Allow the countertops seven to 10 days of drying or curing time before moving or releasing. If working in hot weather, cover concrete with wet burlap, re-wetting as needed. The slower the concrete cures, the stronger it will be.
Remove all screws form the mould and gently pry the sides of the mould off. Carefully turn out the finished countertops and set, topside up, on a secure, flat surface.
Sand the surface of the countertops, using the wet sander and diamond grinding pads, until the recycled glass is revealed. Continue to sand with increasingly finer sand paper until the desired smoothness is reached. Small holes and flaws can be filled during the sanding with epoxy or thinned concrete (sometimes called slurry).
Seal and wax the concrete according to the manufacturer's directions before securing directly to the cabinets or over a 1/2-inch plywood base using construction adhesive and concrete tapcons.