Concrete Basics

What is Concrete Made of

Pouring Concrete

Concrete Mix Designs

Aggregates in Ready-Mix Concrete

Building Concrete Slabs

Concrete Testing

Seasonal Pouring Tips

Repairing Concrete

Concrete Repair

Fixing Decorative Concrete

Applications

Staining Concrete

Stamped Concrete

Concrete Countertops

Concrete Patios

Concrete Floors

Commercial Concrete

Blotchy Spots in a Glossy Sealed Floor

Question:

I recently applied two coats of an acrylic sealer to a stained floor. After the sealer dried, the floor appeared blotchy, with some areas glossy and others not. What causes this, and should I apply more sealer to remedy the situation?

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. The number and depth of these plateaus and valleys is directly proportional to the finish of the concrete. A smooth finish has fewer of them while a rough finish looks like the Grand Canyon. When sealer is applied, it fills the valleys, but you may need to apply more than one coat depending on the finish of the floor. 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. Applying additional light coats of sealer usually resolves this issue. 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.

Find Concrete Sealers