How to Remove Concrete Stains


December 20, 2022

The Problem

Nothing can ruin the appearance of a beautiful concrete driveway, patio, or other exterior concrete surface more than an unwanted stain. Common causes of stains include rust, mold, oil, and organic matter. Not only are stains on exterior concrete an eyesore, they can be difficult to eradicate because they often penetrate into the pores of the concrete.

The good news is that you can remove most of these stains by using the right type of cleaning agent and a bit of elbow grease.

Here’s a look at the best methods for removing the most common stain types.

Mold & Mildew

Mold and mildew growth commonly occur on outdoor concrete located in damp or shaded areas that don't receive a lot of direct sunlight. Wet, humid weather with warm temperatures only improve the growing conditions. The best remedy is to scrub and clean the affected areas with a mold-killing detergent, or a simple solution of household bleach and water.


Unlike many other stains on concrete, rust can’t be removed by using common detergents and pressure washing alone. In most cases, you'll need to use an acid-based cleaner to dissolve the rust. This can range from simple household products like lemon juice or vinegar, to powerful chemical cleaners that contain oxalic acid or trisodium phosphate.

Oil & Grease

Concrete driveways and garage floors are especially vulnerable to oil stains since leaking vehicles are the primary culprit. Not only are these stains unsightly, they must be removed before applying any decorative treatment, such as concrete stains, sealers or coatings, because the oil will inhibit penetration. The size of the stain, as well as its age, will determine the best method to use.

Organic Stains

Organic stains, such as those caused by fallen leaves, tree sap, or pet urine, can be tough to remove because the organic pigments get embedded in the pores of the concrete. For best results, use an organic cleaner made up of enzymes and bacteria that actually eat or break down organic matter.

We Can Help!

If you don't have the time, ability, or mental bandwidth to deal with your concrete stains, we can help! There are ways to stain & seal existing concrete that will make it look brand new. Text or call now to discuss your project: 858-345-0305.

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