How to Make Precast Concrete Countertops

Learn how to make concrete countertops with the popular casting method known as “Precast”.  Precasting is ideal for casting in a workshop or garage where you can control the work environment, ensure optimal curing temperatures, and minimize the risk of damage to finished cabinets or appliances. Precast concrete countertops are usually cast upside down in the mold to maximize custom options and details while minimizing the need for concrete finishing skills.

Precasting a concrete countertop requires fine carpentry skills and elementary knowledge of concrete. This guide walks you through building a form out of 3/4″ melamine and using Sakrete 5000 Plus bagged concrete along with CX Precast Concrete Countertop Pro-Formula to create professional grade concrete countertops.

One: Make a Template

Every countertop project begins with an accurate template.  Detailed notations, measurements, and planning will help your project flow as smoothly as possible.

Two: Build the Mold

Projects destined for the polishing process are typically cast on melamine-coated particle board, an inexpensive, and readily available choice.

Three: Mix the Concrete

Keep your costs low with Sakrete 5000 Plus concrete from your local home improvement center and CX Precast Concrete Countertop Pro-Formula.

Four: Pour the Concrete

The concrete mix used in this pour was low-slump and required heavy-duty vibration. Add more water to your mix if you don’t have table vibrators like these.

Five: Demold Countertop

After 5 days in the mold it’s time to remove the countertop but since the concrete is still young extra care must be taken to avoid problems.

Six: Polish the Countertop

Wet-polish with coarse diamond polishing pads that expose aggregate by cutting deep into the concrete, or use a finer pad for a more uniform finish.

Seven: Seal the Countertop

A good sealer is the best way to protect your countertop from unwanted signs of use and wear. Acidic foods like citrus and mustard will even etch concrete.

Eight: Wax the Countertop

Waxing a concrete countertop protects the sealer from the wear and abrasion of daily use. Pots and pans can take a toll, so wax regularly.