Can Concrete Sealant Fill Fine Cracks?

Learn how common topical sealants can be used for filling fine cracks in your home's concrete countertops from an expert's perspective.

Can Concrete Sealant Fill Fine Cracks?

Common topical sealants can be used for concrete countertops, but getting them to penetrate and fill a thin crack can be difficult. Most concrete countertop sealants have a low solids content, but using a material with a high solids content will ensure that as the sealant cures, the material left in the crack will not shrink and separate from the concrete or, just as bad, leave a vacuum. A highly fluid epoxy (such as a fluid grade granite epoxy) is an effective way to fill and seal a crack very well if it can get it into the crack. It's important to keep in mind that materials such as epoxy are effective because they wet concrete.

Functionally, this helps to get the epoxy into the crack. Aesthetically, this can obscure the appearance of the crack, especially if the sealant used on the countertop does not darken concrete as much as epoxy. Fine cracks are commonly observed in newly laid concrete and their appearance is due to the phenomenon of plastic shrinkage. As the name implies, these cracks are very small, about 0.003 inches (0.08 mm) wide and can be very shallow.

To repair a fine crack in concrete yourself, you will first need a filling of concrete cracks. Unfortunately, you cannot solve this problem with more concrete. Concrete crack fillers are known as masonry crack fillers and come in a wide variety of options. In Australia market, elastomeric masonry crack filler is the most widely applied with a caulking gun to fix the narrow cracks of concrete.

Instead, there are many different products available in bottles with some generic applicator tip. There is no doubt in the fact that small cracks (fine cracks) are often repaired using a vinyl concrete patch material that is worn over the crack and leveled with a flexible knife or trowel afterwards. As for the Australian market, for very fine cracks, the application of putty or crack filler is also very good. It's important to be aware of cracks in your home, they can be narrow cracks, and they can also be deep, often spreading over the entire width of the concrete slab. Therefore, it is a great idea to start the repair by filling the foam backing rod into the narrow crevices to make a base for holding the restoration material. The back-up bar comes in solid form and of different sizes, using a rod width that is somewhat larger than the width of the crack.

To repair the crack, the sealant (or other filling material) must penetrate into the crack and fill it completely. Ideally, the sealant has a low surface tension so it easily moistens concrete and a low viscosity. Another option to minimize existing cracking is to apply a penetrating sealant to protect the surface and repel moisture. It will blur the lines along with the texture of the concrete and in a matte finish, you hardly notice that there is anything there. You may also consider acid-staining concrete for a different type of surface appearance with a darker color to help lines become less noticeable. The causes of these cracks may be due to variations in air temperature, concrete temperature, relative humidity and wind speed on the concrete surface.

And when water freezes and thaws again and again, it can cause the surface of the concrete entrance to crack, break and crumble. The pouring of a thin layer of concrete resurfacing will bond to the existing slab and present a fresh surface finish. It is also possible that the concrete has not been poured under ideal curing conditions or in poorly compacted soil, causing cracks to settle. The biggest concern is that water can freeze and expand in cracks, as concrete already absorbs water naturally and accumulates in areas where there are cracks. By examining the general condition of concrete at least once a year, you can fix any problem areas before they have a chance to expand deeper.

As the concrete deviates under traffic, the brittle epoxy will begin to grind at the joint line and deterioration will begin again. However, integral colors can be used with some repair materials to match the surrounding concrete. Most hardware and tool stores recommend using a filler that has a flexible formula so that masonry crack filler does not come off old concrete as area freezes and thaws. Fine and fine cracks are usually not serious problems of strength as long as there are no other signs of deeper cracking in area. It can cause chemical reaction as cement has lot of lime producing additional acidic concrete.

Fine cracks less than millimeter wide or minor cracks between one and five millimeters are generally not cause for concern. Bacteria do not have big impact on buildings and concrete however they play role in “corona rot corrosion” in raw drainage waters. Engineers believe that without sealing, concrete will be increasingly exposed to friction wear and external causes over time these wetting and drying cycles will cause concrete to crack just like piece of steel will eventually crack if bent back and forth enough times. If your concrete is badly cracked consider tearing it off adding attractive exterior with new entry.