If you have a car that’s leaking out oil, you will find out soon that these stains are very hard to remove oil from concrete. You can even search online for different ways to clean oil from concrete and getting an array of different ideas that may or may not work. Therefore, in this article, I will cover how we as pressure washers can completely remove oil from concrete.
Do This Immediately to Remove Oil Excess
Even if you hire a professional, if you see oil on your concrete, do not ignore it. Allowing oil to set on your concrete will make it that much more difficult to remove. The following products will not completely remove the oil. However, it will absorb the majority. I defiantly still advise you to cover the area using either cat litter or baking soda, which most homeowners’ have in their house. If you don’t have either, you can use a product such as Zep Instant Spill Absorber from Home Depot for a more professional product that is a great option.
Why You Don’t Want to Wait
The reason it’s vital you remove as much oil as possible, is because the oil will travel to the bottom of the concrete pad. If this happens, it won’t matter if you clean it to the point you can’t see the oil anymore. Because the oil will be drawn back to the top of the surface like a straw from the pad concrete.
You can rent pressure washers from Home Depot for just under $100 for the day if you do not have a pressure washer at home. I suggest getting the higher psi model of 3500-4000 psi. Because these models come with 3.5 gallons per minute (gpm) versus the lower psi models that only give 2.4 gpm. Most think pressure washing is all about the psi. When a higher gpm is what you want. To give you an idea, most professionals use 3500 psi and 8 gpm machines.
Surface cleaners make quick work to clean oil stains off driveways. You can rent these from Home Depot. These machines cover an 18-inch path at a time as compared to the gun only coving a few inches. While you pay more, you will be glad you did.
Cost to rent (4 hrs.)- Surface cleaner $23.00 + Pressure washer $67.00= $80.00
Cost to rent (1 day)- Surface cleaner $33.00 + Pressure washer $96.00= $129.00
With the cost of equipment alone, the cost is usually close to hiring a professional to do the job for you.
Average professional cleaning- $150.00
The “Concrete Shadow“
If you used the equipment above, and it still did not remove the stain you’re probably not looking at oil itself. However, what we call a residual shadow. The cause of this shadow is oil bonding with the calcium carbonate in the concrete. The only way to remove this is by completing a process called chemical shock. After you apply the first solution of degreaser, which will have a base of either sodium hydroxide or potassium hydroxide. Further, you want to rinse the area thoroughly to ensure we get all the degreaser off. Then use an acidic product such as Nu Look on the stain. By using a base along with an acid will chemically shock the stain and remove it.
Remove Oil Process
This is a multi-step process and requires two different products.
- Apply a degreaser with a high content of Sodium Hydroxide or Potassium Hydroxide (Lye).
- Allow the degreaser to sit for 10 minutes.
- Never let the degreaser dry.
- You may need to apply again to keep it wet.
- Pressure wash the area to remove the oil (heated water is a big helper- 180o).
- Only some professionals have a heater, ask if they do.
- Repeat if needed.
To remove the residual shadow, continue on…
- Apply Nu Look Concrete Cleaner to the area.
- Allow the acid to set for 5 minutes.
- Never let the acid dry.
- You may need to apply again to keep it wet.
- Pressure wash the area to remove the shadow (again heated water is a big helper).
An Alternative for Removing Oil from Concrete
Even though I covered how to rent a pressure washer and surface cleaner above. Another alternative, that must be done before the stain sets in too long. Otherwise, it may not always remove the residual shadow yet removes the oil, is by using a weed torch. Otherwise the shadow will remain. There’s a great YouTube video I saw explaining this process shown here.
- Presser Washing
- Keep the nozzle at least 6 inches from the concrete as to not dig into it.
- Applying a Base
- Ensure you completely remove the base before adding any acidic products to the stain.
- Applying Acid
- First, Do not use muriatic acid from a local store, it is too strong.
- Second, I do not advise using acid unless they make it for this application.
- Last, if we do this step wrong, it can eat away at the top layer of your concrete.
- Chemicals on your body
- If you get a base on, you flush the area with water for 20 minutes.
- Depending on the acid you use depends on how you need to respond.
- I am not a chemist or a doctor, so I will not be getting into how to stop acid.
- ABOVE ALL JUST USE, AN ACID MADE FOR THIS!