Time: 01:30 Sealing also preserves the decorative treatment by protecting the floor surface from abrasions and stains. Otherwise, you will need to strip the sealer, clean the surface and allow it to fully dry, and then reseal. Today, high quality concrete sealers can block up to 99% of surface moisture. They also may contain volatile VOCs. Concrete slabs and floors can be excellent subfloor surfaces for tile and other floor coverings, but too much moisture in the concrete can cause problems with flooring installations. Epoxy Basement Floor. © Copyright 2020 Hearst Communications, Inc. Wait for a dry spell, open as many windows and doors as possible, use a fan to move air across the floor, and take another test after 24 to 36 hours of drying. After the sealer dried, the floor appeared blotchy, with some areas glossy and others not. Answer: If you were to look at a concrete floor under a microscope, you would see what looks like an endless range of plateaus and valleys. I would consult with your local decorative concrete supplier and get some specifics on potential solutions. After letting the floor dry in 95 F heat for 2 ½ hours, I applied the sealer as directed. Completely cover a small area with a thin layer of sealer, then move on to the next area. Learn more about the types of concrete sealer. Seal-Krete Lock-Down 1 Gal. Answer: It's not uncommon for an uneven gloss to occur after two thin coats of sealer have been applied to a stained floor. The practice of closing doors and windows to "dry-in" a room or building can actually trap moisture and create a steam room of sorts, making the problem worse or creating a problem where one didn't exist. Therefore, it's advisable to have a floor tested for moisture content prior to installing flooring or moisture barriers. You hit the nail on the head in regard to humidity. They tend to wet out faster, even on hard-troweled surfaces. Vapor barriers are a way to keep moisture from getting into the concrete. This is why a vapor barrier under concrete is essential. GCP Applied Technologies provides advanced floor moisture barriers to solve moisture problems for floor assemblies. If this is an interior floor, a wax finish coating can also be applied to fill all the valleys and create a uniform, level layer with consistent gloss. Vacuum or sweep it thoroughly, then scrub it with a mop. This floor is on grade, and the concrete is over two months old with a vapor barrier under the slab. When working indoors, it's usually safer to use a water-based rather than solvent-based sealer, especially if the area can't be ventilated. The lighter areas may be a sign of higher than desire moisture causing the color pigment to dilute. Answer: Sanding will take surface bubbles out, but buffing with a floor machine will not be aggressive enough. The cause is different levels of porosity in the concrete surface. Allow the sealer to dry, usually about 24 hours, then apply a second thin coat as needed. But, if you are thinking of doing it yourself, here are the steps for sealing concrete floors: Film-forming sealers (those that form a protective film on the concrete surface) are the type most often used for interior decorative concrete work. Learn More. Clean a Concrete Basement with Baking Soda. There are two main sealer categories: topical sealers (coatings) and penetrating sealers (reactive). Seals concrete against water seepage, water vapor. I applied a two-part polyurethane sealer to it. The surface has a hard-troweled machine finish, and no additional surface prep was completed prior to staining or sealing. Typically when we see a floor that has blotchy areas of gloss, this means that some areas do not have sufficient sealer to fill the valleys. Decorative concrete expert, and vice president of sales and marketing with ChemSystems Inc, Chris Sullivan, provides in-depth answers to common problems associated with sealing concrete floors. Rinse the floor thoroughly, then use a wet-dry vacuum to remove the water. What causes this, and should I apply more sealer to remedy the situation? See Sullivan's advice on sealer selection. Copyright 1999-2021 ConcreteNetwork.com - None of this site may be reproduced without written permission, Answers to common questions about sealing concrete floors. View this comparison chart of concrete sealers. A smooth finish has fewer of them while a rough finish looks like the Grand Canyon. V-SEAL 101 and V-SEAL 102 are very similar products as they are both reactive penetrating sealers with identical amounts of siliconate active ingredient, but are optimized for different substrate types. And no additional surface prep was completed prior to installing flooring or moisture barriers to solve moisture problems floor! In this case, moisture was trapped under the slab abates go back to the next.. Circulate the air conditioner to help remove moisture cause issues with mold mildew... 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