How are concrete countertops made?
Each concrete countertop contractor has their own proprietary countertop construction method.
In general, however, here are the relevant issues:
· Countertops are either pre-cast in a shop or built on site:
· Contractors who pre-cast like to pour in the shop where conditions are controlled, they use special
casting tables, and they have the countertop in their possession while it is curing and until it can
be adequately sealed.
· Contractors who like to build countertops on site like to do so because they can form the countertop
to any client's particular needs- radius edges, curved corners, etc.
Whichever method, find a contractor you are comfortable with and has references that vouch that the
contractor does the type of quality work you are looking for.
· Countertops are made of cement, lightweight aggregates, and a combination of additives.
· Additives such as fiber reinforcement, silica fume pozzolan, and acrylic are often used.
· Some type of reinforcement is used such as structural steel, wire mesh, fiberglass, and/or fibers.
Sometimes more than one type of reinforcement is used.
· The countertops are cured.
· Countertops are often ground. Jeff at FormWorks, for example, grinds off the surface "skin" with
progressively finer diamond polishing stones. This achieves two important objectives for him; durability
· Countertops are always sealed. The type of seal, method and number of coats of sealer is unique to
each concrete contractor. Tamar at City speak stands by epoxy sealers, particularly in kitchen areas.
The epoxy "is harder than the concrete", she says. She notes that epoxy sealers are not inexpensive and
it takes over a week to apply due to her using two coats. While this adds to the cost, the quality is
superior and the only maintenance that will be required is to apply a good water based liquid wax every
nine months to a year.
These are the general steps in constructing concrete countertops. In a nutshell, you have to go with
the contractor you feel comfortable with and are convinced does the kind of work you desire. They each
have their own method of construction.