How to Transform Your Bathroom with Concrete Countertops (Part2)
After polishing the samples and deciding which one we want to create we are now ready to begin the process.
Step 1: Making the mold. Decide what you are going to do with the mold. What kind of edge do you want? What are the locations of the fixtures, sinks and any other details you may want to add (like a soap dish)? Once these items have been answered you can begin to make the mold. The mold is made with a Melamine plywood base and either Melamine plywood sides or foam sides. The Melamine is secured to the base with screws (more solid and more labor intensive). The foam is secured to the base with double stick tape (not as solid, but much quicker). Both applications are acceptable and must be at least 2" high. Two inches not only gives it a more substantial look, but enables you to reinforce it with steel to minimize cracking.
Step 2: Time to pour. With a finished mold, it is time to mix the concrete and pour it into our mold. This can be done in a couple different ways. If you do not have much experience with concrete you can simply purchase the sacked concrete at your local hardware store. Or you can purchase the cement, sand and aggregate and mix it yourself. By mixing it yourself you have more control over what you put in the mix and what it will look like when it is finished. However, you must make sure that the proportions are mixed properly. If you are buying the sacked version, you need to make sure that you are purchasing at least a 5000 lb. mix. The 5000 lb. mix is best to use for countertops because of it's overall strength and resistance to cracking. You will want to rent a concrete vibrator for you pour too. Vibrating the concrete will reduce air bubbles in the concrete that will be exposed when polishing. These are available at most rental companies. The picture below shows the decorative aggregate and glass that was "seeded" into the top. This is what we are looking to expose when we begin to polish the top.
Step 3: Finishing your countertop. Once you poured you top it must set for a minimum of FOUR days. On the fourth day you can break the mold down and begin finishing the top. The concrete is still at about 85% strength so be careful not to flex or twist the slab. At this point with the countertop out of the mold you can now grind the surface as much as you want exposing some, all or none of the aggregate or decorative pieces you applied during the pour.
Once you have finished grinding the top it must set for another 5-6 days and harden further before continuing with the polishing process. As long as it is done between then and the next 28 days before the concrete reaches full strength.
For more information on concrete countertop pricing click the link and be sure to include your ideas and estimated amount of square footage. We would be happy to respond with an approximate cost for your new countertops.