Concrete MoldsA guide to buying or making your own formwork for concrete countertops, sinks, furniture, patios and walkways
Nearly all concrete placed anywhere is molded in one way or another. A mold is really the same thing as concrete formwork—or shuttering if you're British. But it's usually only called a mold when it is smaller, more detailed—such as for a countertop or a sink or concrete furniture. Although some people refer to stamped concrete surfaces as being molded when referring to the pattern or texture, such as on patios and walkways.
A popular feature of concrete countertops is an integral molded sink. "I do lots of integrally cast-in sinks," said Phil Lampe, Lampe Concrete Studio, San Marcos, California. "I think that takes advantage of what you can do with concrete that you can't do with other materials."
Countertop makers mold these sinks either with their own custom-made molds or with purchased molds. What the molds have in common is that they must be smooth and waterproof and able to hold the concrete in place until it sets. Materials that meet those requirements include fiberglass, Plexiglas, rubber, and polystyrene.
Concrete molds can also be used to create the following:
- Fire bowls
- Fireplace mantels
- Stepping stones
In this article, you will learn a little about countertop molds and a little more about sink mold and countertop mold inserts. For a detailed explanation of how to make a countertop mold, get a copy of Fu-Tung Cheng's book, Concrete Countertop Book.
Custom Concrete Molds
Of course, you don't have to use a standard mold. You can get custom molds from most of the companies that have manufactured molds or you can make your own using liquid rubber.
Single-use molds can be made from expanded polystyrene (EPS) with a slick plastic coating that results in a very smooth finished surface. You can also work with a company that has specialized equipment for making custom molds. These controlled foam carving systems allow you to create anything you can imagine. Remember that you always have to think in terms of a negative to get your positive countertop to turn out the way you envision it.
Concrete Mold Reviews
An inside look at the latest molding products: