Most properly applied sealants last for many years, but a simple fact with concrete flooring is that the sealant will eventually wear away, leaving your flooring dull and blotchy. This occurs especially in high-traffic areas, making the entire floor appear old and unsightly. The only solution for bringing back that like-new look is a fresh application of sealer. There are, however, a few things to keep in mind before resealing that concrete floor.
Don’t think a quick sweeping of the surface to be resealed will be sufficient, it won’t! Any concrete flooring being prepped for resealing must be thoroughly cleaned, preferably with a good detergent and a complete rinsing. Not only does this get rid of any lurking dust and dirt, it cleans away any of the old sealant that may be cracking or flaking. Applying fresh sealant over old is seldom a good idea. You wouldn’t wax your car without washing it first; the same applies in the case of resealing your flooring. Make sure the floor is completely dry before beginning the resealing process.
Don’t wait for a rainy day to start this project! Again, the floor must be completely dry or you run the risk of the sealant ‘blushing’ or not sealing correctly, which only leads to further problems with the finished look of the flooring. High humidity means the air is damp, which means the floor is damp also. For best results, choose a time when there has been no rain for a few days and none predicted for a couple more days. Late afternoon is the time preferred by most professionals for applying sealant.
Winter is not a good time to reseal. The chemical makeup of most sealants is designed to work best when applied in temperatures above 55 degrees; 80 degrees or above is prime time as long as the sealant isn’t being applied in direct sunlight.
The old adage, “if a little is good, then a lot is better”, doesn’t apply to sealants! You will get far better results with a couple of thin coats with plenty of drying time between as opposed to one heavy coat. A thick, heavy coat will not dry evenly and could possibly lead to trapped moisture that will not produce a smooth, even finish. Read all directions carefully, or talk to a professional.