Concrete counters can be home made
Q. My vanity countertop and sink need to be replaced. I thought about making a custom colored concrete one myself. If it goes well, I will try it for the kitchen. What are the basic steps for this project?
A. Concrete countertops are becoming much more popular in bathrooms and kitchens in today's homes. Concrete is a reasonably priced, readily available, environmentally friendly material. Since it is formed in a mold, unique custom shapes and styles are possible.
As you mentioned, it would be wise to start with the bathroom vanity for experience and then try the larger kitchen countertop. Making a concrete countertop is not a difficult project, but it will take a little practice and a lot of initial research to do it properly. The basic construction concept is fairly simple, but mixing and working with the wet concrete is often more of an art than a science.
The first step is to design the shape of the new vanity top. Try to keep it as simple as possible since this will be your first attempt at making a concrete countertop. Plan on forming the bowl with concrete so it is an integral part with the vanity top. This looks nice and eliminates the possibility of leaks and dirty joints and seals.
You will need a strong table at least the size of the vanity top. Even a small vanity top can be quite heavy when it made from thick concrete. Braces for the sides of the form can be screwed into the wooden top, so the table top will be ruined unless you first place a piece of plywood over it.
The basic form for the vanity top is made from ˆ¾-inch melamine. This material is relatively easy to cut to size and to work with. Its surface is smooth so the top and sides of the concrete vanity will also be smooth when the form is removed. Support the outside of the melamine side pieces with 2-by-4 lumber and then screw braces into the table top.
Making the form for the sink recess is a bit trickier. Build a simple rectangular tapered design with the deepest area near the back underneath the faucet. Glue a piece of PVC pipe to the sink recess form to create a hole for the drain pipe when the concrete is poured. Addition small side forms will be needed around the recess to create the proper concrete thickness.
The final preparation step is to make a rebar (reinforcing steel rod) cage to be embedded in the concrete. Concrete is very strong in compression, but is needs steel reinforcement when spanning a vanity. Use steel wire to connect the rebar piece together into a cage.
Mix and color the concrete to be poured into the vanity top form. A typical mixing ratio is three parts of white sand, 1 parts of -inch gravel and 1ˆ¼ parts of type-1 Portland cement. Adding a water reducer and plasticizer can make the wet concrete flow better. Use a vibrator to make the concrete flow into all the corners.
When the concrete is set, remove the forms. Lightly grind the surface with an abrasive pad to expose tiny bubbles. Fill them with a thin coat of colored concrete and acrylic bonder. Apply sealer and a coat of wax.
Ms. Builder's column appears Sundays in Homes Plus. Send questions to Ms. Builder, 6906 Royalgreen Drive, Cincinnati, OH 45244, or visit www.msbuilder.com.
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