What Does Dawn Dish Soap Do To Concrete?

Chances are, you probably take your concrete driveway and garage floor for granted. Those sturdy surfaces support your car, large home projects, chalk drawings, games of hopscotch, and even occasional front-yard gatherings or yard sales. You certainly want the best concrete for your driveway so it holds up to years of heavy use in any kind of weather.

Dish soap and concrete have a surprising love-hate relationship for two substances that seem so far removed from each other. Dish soap has many unexpected uses around your house and yard, but the old contractor trick of adding it to concrete — particularly in colder climates — is one to avoid. The trick centers on the belief that mixing even just a tablespoon of Dawn into a bag of ready-mix concrete creates soap bubbles that basically harden in place with the concrete and can prevent cracking caused by seasonal freezing and thawing long after the concrete cures. Another belief is that it can help concrete pour more smoothly and take longer to harden, giving workers extra time to spread the material.

The problem is that contractors have no way to guide or control the even distribution of those little bubbles, creating unevenness and inconsistency in the mix and reducing the compressive strength of the surface. It also may not mix correctly for the perfect pour and, because it wasn't made to mix with concrete, can ultimately defeat the entire purpose of combining the two. Commercial air entrainers are a much more reliable tool for the job, though that too may need added cement to achieve the desired consistency.

Dawn and concrete work well together in a different way, though. Over time, all that driveway activity — particularly from automobiles — can result in unsightly oil spills that may even degrade the structural integrity of the slab and create a slip-and-fall hazard. Even though numerous top-rated products for removing oil stains from concrete exist, one of the simplest options is that trusty bottle of Dawn dish soap next to your sink. It's an affordable and effective degreaser for fully cured concrete, especially when mixed with hot water and used as a pressure-washing solution.

Pressure washing can help prevent a driveway from cracking and maintain your home's curb appeal, but may not be the right choice for painted concrete so test a small, inconspicuous area on low pressure first. To do the job right, check the pressure washer's manufacturer guidelines to make sure you don't void the warranty. Spray the concrete with warm water on the low-pressure setting to get rid of any loose debris. In a big bucket, fully dilute 1-2 ounces of Dawn per gallon of warm water before pouring it into your device's clean detergent tank. Starting at the base of the driveway, apply evenly across the surface. After waiting 10-15 minutes for the solution to break down the oil, give it a scrub with a heavy-duty brush. Using the highest pressure your surface will tolerate, thoroughly rinse the driveway. Then stand back and admire your oil-free concrete.