When time and money has been spent installing decorative concrete and overlays, perfection is expected. However, issues can and do arise when it comes to sealants, whether you do the job yourself or have it professionally done. A little extra time and effort is required to help prevent some of the most common sealer problems – always read the labels and familiarize yourself with the product being used if doing the sealing yourself, or make sure your contractor has experience with the product and its possible issues.
Here, then, are the most common problems you may face:
1. Sealer bubbled – The usual cause of bubbling is over-application, causing air bubbles to form which will pop as the sealant dries, leaving unsightly marks on the surface. Instead of one thick coat, most sealant manufacturers recommend two very thin coats with a drying time between applications. Another cause of bubbles, when sealant is applied to an outdoor surface, is the heat and sunlight. Application should always be done during the coolest part of the day for the best results.
2. Solvent-based sealer turned white, is peeling or flaking off – Again, over-application may be the culprit. When a thick coat is applied, the solvent evaporates at a faster rate on the surface, trapping moisture underneath. Blushing will also occur if sealant is applied to wet or fresh concrete that has not had time to properly cure. Flaking and peeling happens because the sealant cannot bond correctly to the dampness in the concrete.
3. Water-based sealer is white or powdery – This is not a good choice for exterior use such as pool decks or any area where puddles may form. Applied during high humidity or low temperature days, the sealant cannot dry properly and evenly. This prevents proper bonding and results in a cloudy or powdery finish.
4. Sealer is stained – grass, leaves, oil, etc. – Acrylic polymers, the most commonly used sealant, don’t add much in the way of stain resistance. A far better choice in areas prone to possible staining is an epoxy or urethane blend.
5. Concrete is dark or blotchy – All concrete is somewhat different in appearance, depending on the mix. Just as varnish brings out any flaws in wood, sealants will highlight issues in the concrete. Some sealants will darken the appearance and give a more high-gloss finish while others won’t darken as much and give a lower gloss level.