Kitchen Trends: Concrete Countertops

While researching my latest home improvement article, I was amazed at the options available in concrete countertops. You can add pigments, glass aggregates, tint it, stain it, add curves or angles and include drains boards and flush mounted sinks. You can even add fiber optic lighting in the top for a one of a kind look. If you decide to try the lighted options, it is probably better that you hire a professional installer. The options available are bound to suit your design needs and desires. I have installed a couple of concrete countertops, so I am not exactly an expert in the process, but I can give you some tips on design and installation.

If you decide to tackle this project yourself, I suggest that you read a lot on the subject and once you're done reading, pour a couple of test tops outside or in your garage so that you can learn how to get the desired result. Concrete countertops are typically poured at about one and one half inches thick making them comparable in weight to granite or marble. With that in mind, your countertops should be reinforced to support the weight. If you plan on casting in place (on top of the cabinets already installed) then you need to put a layer of 3/4" plywood for the base of your form. This layer should be concealed by the edges of your top, the best way to do that is for the top to dip down at the edge of plywood; however, you should be extremely careful to prevent your top from keeping the drawers and doors from opening. Try and caulk all seems and joints in your form before you pour so that the water from the concrete doesn't damage the counters below.

The endless options for edges leave you to decide on what type you want, whether you want them to be the same as your top or you can have a stainless steel or copper edges built which can serve as the form and a finished edge. I have seen this done and it adds a distinctive accent to the countertop especially when it matches the sink and other appliances in your kitchen. The other option for your edges can be a square or rounded edge or a scrolled edge which can be made by building the exact opposite of the result into the edge of your form. If you choose this option, be sure to vibrate the edge well to keep pockets of air from leaving voids which can be almost impossible to fix and blend to the rest of the finish. Once again, this is where pouring a practice top can make the difference in a botched job and a professional look.

Before you pour your top, research methods to reinforce your top. Regular wire mesh which is used in slabs will work, the drawback to this type of reinforcement is keeping it from coming to the top of your finish. It is better to use a fiberglass reinforcement made specifically for concrete tops. If you cannot afford the fiberglass reinforcement or you cannot find it, you can use galvanized chicken wire. Take the wire and stretch it from nails to keep it in the bottom third of the slab without laying on the bottom. If your reinforcement is laying on the bottom it will not do any good. You have to use a reinforcement material because all concrete cracks, it is it's nature. You cannot prevent concrete from cracking the best you can do is to try and control it. If your top is large or has several wings on it, you may want to consider a control joint. A control joint is a deliberate break in the slab which can be caulked or you can use a finished piece of material and leave it exposed as an accent. If done correctly, this will add to the look instead of taking away from it.

When forming your top be sure to allow for your sink or any other accessories which are integrated into your top. This includes allowing for clearance of your dishwasher, stove or any other items which may be effected by the top. If your planning on installing a flush mounted sink, purchase the sink before you pour and make sure that if you need hardware to hold it in place you have allowed for it. This may be that your plywood form underneath may need to be cut back an inch or more from the edge. This will be almost impossible once your top is poured, which means you may have to get creative with your form-work. This is another reason to pour a test top, you don't have to make a full sized top, you can make one edge of the test form as a mock up for sink installation. Better to fail on a test than on your finished product, if you fail with the finished product, you may have to remove the entire top and start over, this is something you do not want to do.

If you have chosen to use exposed aggregates or glass aggregates, then you will need to use a retarder to keep the top from setting while you install these materials after you have poured. The other option is to mix the aggregates throughout the materials, which will increase the cost of your top, and you will still need to use the retarder. Once the concrete has set, you can wash the retarder off to reveal the aggregates. The other option is to use the diamond polishing method to remove the top surface and reveal the aggregates. Once again, this makes an even better case for pouring a test top.

Once your concrete has set up, it is time to finish it. If you want a really slick surface, which I assume you do, you must either sand or polish the top. If you don't have the equipment to diamond polish the surface, you can sand it with a series of finer and finer sand papers and achieve the same results. The only drawback to this process is it is extremely labor intensive. Once you have it polished, you will want to seal it. Concrete is a porous material that will stain easily, for this reason sealing is a must. Once it's sealed, you may want to wax the surface to achieve an even greater shine making it even more like a polished granite or marble.

When it comes to materials, you can use the pre-packaged bagged concrete from your local home improvement store. However, they do make a highly engineered concrete just for countertops. Either way you go, make a couple of test tops so that you can achieve exactly what you want. You may find that the edge you have chosen isn't practical meaning that you can make this mistake without having to live with it. Another pointer is that if you pour your top in one piece and in place it will make demolition of the project extremely difficult and you will more than likely destroy your cabinets while doing so.

Another point to consider is the back-splash. This can be extremely hard to form and pour as a part of the top. What you can do is to pour the back-splash in separate sections and install it after the fact. Don't try and pour a piece of back-splash over four feet long as more than likely you will never get it installed without breaking it. Better to pour it in four foot sections and caulk it in place. You can use a colored caulk which is close to your finish color or use a clear caulk. Make sure and use a compatible caulk for the materials you are using.

The other option here is to have a stainless or copper back-splash made which wraps around a piece of 3/4" material and pour up to it. This looks great especially if you have had the edging made the same way. If you choose to add a metal accent to your top, coat the area that is directly exposed to the concrete with a protective coating. Concrete is alkaline and will corrode the metal slowly over time. Better to use an ounce of prevention to begin with than to regret it later.

Concrete countertops also need to be maintained. This means sealing and waxing on a yearly basis to prevent staining. It also keeps the top looking like new and like you intended it to. Choose these materials wisely as this is not the part of the project to skimp on. Whether you get creative and add arrowheads or a wine bottle from your wedding, this is a project which you can be proud of. Concrete countertops are one item which gets daily use, every time you make a sandwich or your daughter spills soda on it, you will remember the time you put into it. Make it count, this is one project you don't want to mess up on, the result of failure is doing it all over again or having to live with a sub-standard product. Good luck and do your homework, this is one time it really counts.