Problems with concrete sealers can be an issue in concrete specialists. When a concrete sealer doesn't perform or look in the way you expect, the issue is usually traced back to the excessive application, application in unsuitable conditions, or the buildup of several coats. Here are five sealer problems that contractors might confront, their causes, and what you can do to prevent the problems.



PROBLEM #1: SEALER BUBBLED

The appearance of bubbles in on the sealer is typically the result of a large application. The outgassing that occurs off on the Concrete Resurfacing in the course of sealing must be able to move quickly through a thin and wet sealer film. What is the definition of thin? If you are using a cover rate of about 300 sq ft per gallon, a coating of an acrylic cement sealer will be 5 mils in thickness when it is wet. After drying the sealer will be around 2 mils thick. (For comparison, a piece made of paper for copying is around 10 mils thick, and credit cards are 120 millimeters.) If you apply the sealer too much the air trapped within the surface is unable to escape and forms bubbles on the surface of the sealer.

The bubbling of a sealer may be a possibility if the application is carried out in hot weather or when the concrete is exposed to direct sunlight. In these circumstances it can "skin over" and dry on the surface prior to all solvent evaporates. The tension of the solvent trying to evaporate will create bubbles on the surface of the sealer. It is best to apply sealers in the cooler part of the day when concrete is not exposed to direct sunlight.

PROBLEM #2: SOLVENT-BASED SEALER TURNED WHITE, IS PEELING OR IS FLAKING OF

Two main causes contribute to "blushing", or whitening of a solvent-based concrete sealer. The first one is when it is applied to the concrete surface which is wet fresh concrete that has bleeding water. If this happens the sealer won't adhere to the concrete, but will instead flounder on a layer of water. The other reason that sealers blush is when it's applied too thickly. The application of thick coats of sealer or a build-up of sealer that has been applied repeatedly throughout the years could result in moisture becoming trapped in the sealer. Then, eventually, the sealer begins to lose bonding to the concrete. In this case, the trapped moisture and the air that is trapped under the debonded sealer have an index of refractive so that it appears to be white to the naked eye. Over time the sealer can peel off or flake off of the surface. To avoid this issue adhere to the guidelines of the manufacturer regarding coverage and quantity of coats recommended.

PROBLEM #3: WATER-BASED SEALER IS WHITE OR POWDERY

The process of drying water-based sealers is complicated and greatly affected by the temperatures and humidity of the surroundings during the application. Water-based acrylic sealers dry through a process known as coalescence where the water, and later the solvent that coalesces evaporates and combine the acrylic particles into the film of sealer. If the temperature at which you apply is too low or the humidity is too high the coalescing solvent may evaporate prior to the water so that the sealing material will become as white or powdery as the latex particles failed to bond prior to drying. Make sure you know the conditions of temperature and humidity that are necessary for the effective application of a water-based sealer.

PROBLEM #4: THE SEALER IS STAINED FROM OIL, LEAVES, TIRES, FERTILIZER, ETC.

The most commonly used concrete sealers are made from acrylic polymers, which do not provide superior stain or chemical resistance to concrete. To provide more endurance and protection from chemicals and staining, think about an epoxy or urethane-based coating system. Also, make sure you are suitable for use on the outside prior to applying it to outdoor concrete.

PROBLEM #5: CONCRETE IS DARK AND/OR BLOTCHY AFTER SEALER IS APPLIED

The majority of acrylic sealers darken concrete, and create shiny shine to a certain degree, giving the concrete an appearance of a "wet look". Because each slab is distinct in texture and color the color of concrete following the application of sealers is not easy to determine. Mixing design, usage of chemical admixtures, finishing methods, and porosity are only several factors that can alter the color of the concrete's surface. Sealers will enhance the concrete's true color and highlight the subtle differences in surface texture that result from the floating process and its finishing. Sealers can also highlight some of the "grain" in concrete just as a varnish would on wood. If the color of concrete changing after sealing is an issue then use a penetrating water repellent sealer, or perform an experiment with an adhesive sealer that forms films to make sure that the change in color will be in the right direction.