How to Construct a Stamped Concrete Overlay
One of the quickest ways to cover dull, stained concrete, is with a stamped concrete overlay. You can add color and texture to the overlay to better conceal the surface below. Follow these directions to prepare and lay a stamped concrete overlay indoors or outside during a long spring or summer weekend.
Step 1 - Clean the Concrete Surface Completely
Move all plants, furnishing, and other objects off the concrete surface. Sweep with a stiff bristle broom, and spot clean any stains with warm water and a degreasing liquid soap. Tape off the edges near lawns and lay a narrow border of plastic film to protect from splashing.
Step 2 - Apply Surface Primer
The surface primer is a liquid polymer that goes on white and opaque like milk. Pour it directly onto the surface and spread out thinly over the concrete. Allow the primer coating to dry overnight. Put on a second coat of primer the next morning, and let dry for about 2 hours at 60 degrees Fahrenheit (16 degrees Celsius) or warmer. Cooler temperatures will mean a longer drying time.
Step 3 - Mix the Concrete Coating
In a 5-gallon bucket, mix the color and polymer as specified in directions, and stir with the mixing paddle turned by the electric drill for 15 seconds. Add the concrete mix slowly and keep the mixing paddle turning. Blend the concrete, color, and polymer until it is the consistency of pancake batter, and beat out any lumps.
Step 4 - Pour and Spread the Concrete Mix
Pour the concrete mix out onto the floor in a circle 3 feet across. Use the squeegee to distribute the mix across the surface evenly. As soon as you do the first section, have your helpers start laying the stamping mats.
Step 5 - Lay the Stamping Mats
Spray each stamping mat with a releaser and lay them on the concrete covered sections. Use a laser ruler to line them up precisely. Press them down and release, leaving them on the concrete for 5 minutes, then lift off carefully. Once you have done the first section, use it to align all the others.
Step 6 - Allow the Stamped Concrete Overlay to Dry
Allow at least 24 hours of drying time, for a stamped concrete overlay, to allow the design to penetrate well into the concrete.
Step 7 - Apply Concrete Sealer
If the stamped concrete overlay surrounds a pool, use a silane or siloxane waterproofing sealer. Add transparent polyethylene beads to the sealant to reduce slipping, and spread it out with a microfiber mop. Permit the first coat of sealant to dry completely and apply a second coat 12 hours later. Use either a water-repellent sealant or a gloss sealer on a patio to bring out the overlay's texture and shading.
Maintain a stamped concrete overlay by washing every few months with the garden hose, and sweeping off dust and dirt weekly.