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March 02, 2017 • Mike Huber

How To Prevent Common Sealer Issues

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If you read last week’s blog post, you’ll remember that we said sealer is the scariest product that a hardscape professional encounters. In this post, we’re going to discuss why. Here are the most common sealer issues we see out in the field and some tips on how to prevent them.

Photo Credit: www.beeyoutifullife.com


Ever sealed pavers before? Then you know it’s not an easy job. Not only must you pick the optimal product for the project, but your application technique needs to be very precise. Getting it right the first time is imperative because repairing a botched sealer job is messy, expensive, and labor-intensive. Learn what not to do by reading through this list of common sealer issues.

Don’t miss this related blog post! Steps For Sealing An Outdoor Concrete Patio


Plastic Appearance
A plastic appearance on a sealer job typically stems from over application of the sealant. (To get an even coat, it’s best practice to first use a sprayer and then back roll.) In some cases, Xylene may be able to correct a plastic-like appearance of a solvent based sealer.


White Lines
White lines on a sealed surface are generally linked to one of two causes: the rolling technique or an unclean surface. Xylene may be used to fix or strip a solvent-based sealer while harsher chemicals will be needed for water-based products. Prior to performing any sealing job, it is mandatory to clean the surface with an efflorescence cleaner. Not only will this remove any dirt or debris, but it will also assure a deeper penetration of the sealer and optimal product performance. To prevent roller lines, the sealer can be applied using a sprayer and then gently back rolled to even it out. (Tip: Make sure you are not trying to roll the sealer as it is drying.) 


Sealer Not Sticking To Surface
We see many problem jobs where the sealer doesn’t stick to the surface. Nine times out of ten, this is a direct result of an unclean surface. On these jobs, the sealer must be completely stripped and the surface must be thoroughly cleaned with an efflorescence cleaner prior to resealing.


For helpful preparation advice, read our blog post: 4 Things To Do Before Sealing Your Pavers


Flashing refers to an uneven finish of the sealer. We most often see this occur on jobs where the surface temperature and/or air temperature was very hot when the sealer was applied. As a general rule of thumb, a hand test should be conducted if temperatures seem questionable. If the pavers are too hot to touch, then they are definitely too hot for sealing. (Usually anywhere between 60-80 degrees is ideal.)


Expert tip! An IR thermometer is a great investment if you plan on offering sealing services regularly. In warmer months, it may be necessary to seal earlier in the morning to obtain ideal temperatures.


White Spots
Checking the forecast before any hardscape project is a must … especially when it comes to sealing projects. If your job becomes plagued by white spots, it’s usually an indication of trapped moisture. The spots can show up days, or sometimes even months, after the project is finished. Depending on the severity of the spotting, Xylene may be able to correct it (especially with a solvent-based sealer). To avoid the damaging effects of moisture, be sure there is no rain predicted for at least 24 hours after the sealer gets applied.


If your pavers appear to have a milky white coating after sealing, it can be attributed to a few different factors. If a water-based sealer was used and temperatures were too low at the time of application, this could result in cloudiness. It could also mean that moisture got trapped in the sealer while it cured. Lastly, if sealer was applied to freshly poured concrete, this could also result in a milky white coating.


The resins used in some sealers aren’t UV stable and can therefore yellow over prolonged periods of being hit by direct sunlight. It’s critical to choose the right product for each individual sealing application. To help you in the decision-making process, we put together two informative blog posts that explain the various types of sealers on the market:


Like we said … sealing is scary business! But if you enter the job equipped with knowledge, you’ll be a rock star!


For more on how to perfect your sealing skills, be sure to download a free copy of our newly released SlideShare: Sealing Gone Wrong.


Looking for a fast and easy online resource that covers all of your questions about sealing concrete pavers? Click here!

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