When concrete sealer does not perform as it should, the root of the problem can typically be traced back to over-applying the product, applying the sealer in improper conditions, or allowing multiple coats of sealer to build up on the slab before they have dried. There are other issues that you might face when applying sealer to decorative concrete, including the following:
Bubbles in the Sealer
The presence of bubbles within the sealer is often an indication of over-application or off-gasing. For best results, sealers should be applied in multiple thin layers. In the event that there is any air displacement or off gassing, a thin application will make it possible for the bubbles to move quickly through the film and pop. Ideally, it is best to apply sealer to decorative concrete in two thin coats rather than one heavy coat. The first coat should serve as a primer, most of which will be absorbed into the surface of the concrete. It is only when the second coat is applied that you will begin to see an even finish and glossy color enhancement. Another trick of the trade is to apply sealer when a concrete slab is cooling (in the evening)- heat from a hot day will cause the concrete slab to warm, expand and “breath out” while a cooling slab will shrink and “breath in”.
Flaking or Peeling Sealer
If you have noticed that the decorative concrete coating is flaking or peeling or seems to have a white appearance, the problem is likely due to applying the sealer to a surface that is too wet, fresh or moist. This results in the sealer failing to absorb and bond with the surface of the concrete, causing the sealer to float or sometimes trap a film of water underneath it. Over-application can also cause this type of problem. To avoid this problem, it is important to follow coverage rate directions meticulously and make certain the surface is properly prepared and completely dry before applying the sealer.