Stamp concrete often contains designs or patterns designed to give it a more pleasing appearance. That can cause problems when cracks appear or you wish to overlay it with a new layer of concrete. Do-it-yourselfers can overlay concrete very easily and add new stamping without too much difficulty. The trick is not to worry about the stamp pattern you are covering up, but rather ensuring that the new layer has the same pattern as your old concrete.
Instructions
1. Clean the surface you wish to overlay to get rid of any dirt or debris.
2. Apply a thin coat of polymer primer to the surface of the concrete and let it dry overnight. Then apply a second coat of primer over the first.
3. Lay a protective tarp down over the area where you intend to mix the concrete.
4. Mix up the concrete in a 5-gallon bucket using the polymer, concrete mix, water and any desired coloring. (The exact measurements of each ingredient will vary from brand to brand; the instructions on the concrete mix should provide precise details.) Stir the mixture using a broad drill head on a low setting and a mixing paddle until its consistency is smooth. Each bucketful should be enough to cover about 200 square feet of surface.
5. Spread the mixture across the surface with a trowel. The mixture should about 1/8-inch thick, and as smooth as you can make it. There should be no signs of the earlier stamping on the surface. Allow the mixture to dry for at least 5 or 6 hours.
6. Prepare and add a second coat of concrete over the first. The layer needs to be thick enough for you to stamp your patterns into it without coming into contact with the original surface. Watch for air bubbles or other irregularities.
7. Use concrete stamps to stamp your new pattern into the surface of the concrete. You should do this while the top layer is drying, but is still workable enough for the stamps to have an effect. Allow the concrete to dry in its new pattern.
8. Apply any paint or decorations you wish over the dried concrete, and allow them to dry.
9. Apply a coat of sealant over the entire surface. This will protect the concrete from adverse weather and help it retain its aesthetic value. Let the sealant dry for at least 3 hours before attempting to walk on it.
