How to acid wash and seal your concrete with Ghostshield

Sealing your concrete is a highly recommended investment. While it is a fairly inexpensive process to DIY, it will save you more than just money in the future! Sealing your concrete not only improves the longevity and overall appearance of it but it prevents against a lot of harsh elements. Some of these include UV rays, pitting, spalling, cracking, stains, mold, mildew just to name a few! Sealing your concrete, especially when it is new will result in a clean and easy-to-maintain surface that will have an enhanced appearance and add value to your home or business for years to come!

To seal your concrete/pavers/bricks etc, below is a detailed guide to help you achieve the best result possible:



Step 1


Clean and prepare the surface. Start by sweeping the concrete to remove all loose dirt and debris. If the concrete is new, move onto step 2. If it is old, then check the concrete for any stains or mastic that is stuck to the concrete such as resin or gum etc. It is best practice to remove all the stains and mastic before sealing. Once sealed, they will show through the sealer and be trapped permanently.

Depending on the type of stains, you may need to visit your local DIY store and purchase a stain or grease remover to help prepare the concrete. Any mastic, try removing with a paint scraper or similar.


Step 2



Acid wash the concrete. Regardless of whether the concrete is new or old, this step is critical. Acid washing the concrete will remove any surface mineral deposits and efflorescence while opening up the pores of the concrete, allowing the sealer to bond properly to the concrete for enhanced and longer performance.

The first step is to mix the right ratio of acid-wash to water. Make sure you always add the acid to the water and not the other way around. Also, remember to wear protective clothing and safety glasses and be mindful for the surrounding conditions as the run off can harm plants and contaminate fish ponds and animal food sources.

Acid to water Ratios:

Plain concrete                    1:6

Coloured Concrete            1:14

Exposed Aggregate           1:12

Old Concrete                     1:12

Light Bricks/Pavers            1:18

Dark Bricks/Pavers            1:12

Firstly, saturate the area to be cleaned with water, making sure the entire surface is thoroughly wet. Then pour the Acid-wash onto the concrete evenly with a watering can, making sure you cover the surface uniformly. Do a small area at a time and try to finish each can of acid wash on a grout line or cut in the concrete. The Acid wash should bubble and fizz briefly, as evidence of it reacting with the concrete. During this stage, help the process along by aggravating the acid-wash into the concrete lightly with a broom. During this entire process, do not let the concrete dry out at all. Lightly mist the concrete with water if necessary. Once the process is finished, thoroughly flush the concrete with water, ensuring all acid is completely diluted and removed from the concrete.


Step 3


Seal the concrete. The first step is to make sure the concrete is 100% dry and free from moisture. It is recommended waiting 24 hours between acid washing and sealing. One way you can test the moisture content of the concrete is by placing a piece of plastic or gladwrap over the concrete. If the concrete is still damp, moisture will form on the plastic/gladwrap.

To apply the sealer, you can use either a paint roller, brush or hand-pump sprayer (recommended). Work on a small area at a time and apply consistently and uniformly. Make sure to apply 2 coats, wet-on-wet. Try not to apply the sealer in the heat of the day otherwise it will dry quickly and make it very hard to apply the coats wet-on-wet. If the first coat begins to dry, you will find it will start to repel the second coat immediately. 

Once concrete is coated, leave to dry. You can walk on it as soon as it has dried but wait 48 hours before driving etc on the sealed concrete.


Step 4


Enjoy your protected concrete! The process is finished and you can enjoy a few years without having to get out and water-blast your concrete every month!

Resealing your concrete is recommended every 2-3 years. It is a lot easier the second time around and it will go a lot quicker!


If you have any further questions, please reach out to us and we will be more than happy to help you! To visit our products online and to view all the products mentioned above that you will need, click the following link: