How to Troubleshoot Concrete Stamping & Overlay

Look for signs of delaminating failure between the overlay and the concrete beneath. This occurs when the surface of the concrete is too smooth, giving the overlay little to bind with. Repair this sort of failure by removing the overlay completely. Use a sledge hammer to break the surface into pieces and then roughen up the concrete surface with a concrete grinder before reapplication of the overlay material.

Remove raised areas on the concrete caused by the edges of adjacent stamps squeezing the concrete up between them during the stamping process. Roll these edges out with a touch-up wheel right after finishing the stamping process while the concrete is still malleable.

Examine the stamped overlay for cracks matching those present in the concrete slab beneath. Any crack unrepaired before applying the overlay will show through the overlay once its in place. Fill the resultant overlay crack with caulk or grout colored to match the overlay. The crack will remain visible, but due to the color matching, will blend in better with the stamped overlay. Allow the caulk or grout to cure based on the manufacturer's suggested waiting time.

Repair cracks along the edges of the stamped areas due to concrete shrinkage. Fill them with colored cement paste tinted to match the concrete. Spread the paste into the cracks using a gloved finger, and then feather the edges to blend the patch in with the surrounding concrete with a damp sponge. Allow the patch to dry with the remaining stamped surface after patching.

Smooth out rough stamped surfaces with a buffing machine containing a black rough-bristle pad. Run the buffer over the concrete in rows, working the machine in small circles over the stamped surface to avoid cutting gouges in the concrete. Check the surface for smoothness after a pass, and if you desire a smoother surface, run the buffer over the stamped area again. Be careful you don't remove stamped details or the stamp entirely with too many passes of the buffer. Sweep away any concrete dust with a broom and then seal the surface, only after allowing new concrete to cure for 28 days and by brushing on two or three layers of a low-solids acrylic sealer.