White efflorescence on paving stones - where do they come from and how to get rid of them?

A light tarnish often appears on newly made cobblestone surfaces. White spots on colorful paving stones effectively spoil the carefully designed vision of the surroundings, which the owners often follow when designing paths or bands around the house.

Fortunately, the efflorescence on the ankle can be fought and it is quite easy to get rid of them. Just use the right remedy and the problem will disappear quickly. Read what to do when you notice a white coating on paving stones .

Where do lime efflorescences on paving stones come from ?

The white coating on paving stones is formed during the production process. Individual elements of building haberdashery are produced using the vibropressing method. The process consists in subjecting the concrete mix to two processes simultaneously - shaking and compression.

By using this method, manufacturers can be sure that the consistency and cohesion of concrete in each cubic centimeter of material will be almost identical. As the mass is compacted and formed, the water reacts with the cement, carbonating the calcium hydroxide, CaOH 2 . Carbonate efflorescence can occur both during the maturation of the paving stone, during the storage of materials, and after laying the paving stone on the ground.

You must be aware that although the formation of efflorescence on paving stones and other construction accessories affects the final aesthetics of the product, it is not the result of the use of poor-quality raw material by the manufacturer and the complaint will not be considered.

The tarnish also does not indicate a technological defect of the paving stone. This is indicated by the fact that construction standards and technical approvals do not specify white bloom as a criterion for product quality. Especially in the PN-EN 1338 standard "Concrete paving stones. Requirements” it was indicated that possible efflorescence does not affect the performance properties of the paving stones and is not considered significant.

How to remove white coating on paving stones ?

Professionals indicate several methods that you can implement to remove discoloration on paving stones . Start with one you can use yourself. It may turn out to be sufficient.

In the case of more advanced methods (e.g. sandblasting), without proper practice, it is easy to create microdamages that will deteriorate the performance properties of concrete (e.g. by opening its pores, reducing the ability to self-cleaning). What methods of removing efflorescence can be distinguished?

Mechanical ways of removing calcareous efflorescence on the ankle

The easiest way is to use a pressure washer. You can clean the white coating with water, possibly mixed with a mild detergent. The advantage of using a washer is the ability to precisely direct the water stream even to hard-to-reach places.

This is a good way if you need to remove tarnish from nooks and crannies of a parking lot or narrow alleys. However, the method requires the purchase of a washer. It is also labor-intensive, and the results, especially in the case of stagnant sludge, may differ from expectations.

Chemical methods of removing white coating on paving stones

The second action you can take is the use of specialized chemicals. The chemical method consists in leaching the surface with a low-percentage solution of organic or inorganic acid.

In practice, hydrochloric, acetic or formic acid are most often used. You can apply it to the surface manually, using a washcloth or other method recommended by the manufacturer of the preparation.

You must ensure that the concentration is sufficiently low, otherwise corrosion will enter the concrete block, which will gradually change its structure until visible cavities are formed. Therefore, if you lack experience, it will be better if you use the help or advice of specialists.

Radical ways to fight efflorescence on paving stones

If simpler methods did not bring results, you can use grinding or sandblasting of the paved surface. These are advanced methods, the use of which requires a lot of experience.

For both grinding and sandblasting, you must have the right equipment (grinding discs, sandblasting nozzles) and use far-reaching precautions (glasses, earmuffs, protective suit). It is also crucial to choose the diameter of the sand grains and the pressure of the water stream, which should not be too high, otherwise microdamages may occur in the surface of the pavement.

Regardless of the method used, after the work is completed, you can decide to impregnate the paving stone, which will affect its strength, consolidate and unify the natural color of the concrete.

Do calcareous efflorescences on the ankle disappear on their own?

If you don't want to think about what to use to remove white spots, or you're concerned about causing damage, you can just wait. Remember that the white coating is a completely natural phenomenon and will disappear on its own over time.

How long you will have to wait for the limestone efflorescence to completely disappear depends primarily on the intensity of the discoloration. Small stains will disappear after a year, larger ones after three. Wiping is accelerated by rainfall and intensive, mechanical use of the surface (e.g. frequent car passages).

White efflorescence on paving stones will disappear faster from the surface that is not roofed, so it is better to reserve the use of more invasive cleaning methods to those fragments of the pavement that are more protected from weather conditions.

Where to buy anti-blooming agents on the ankle ?

Chemical agents for lime efflorescence can be found in construction stores. They are also sold by wholesalers specializing in the sale of construction chemicals and other chemical products, such as Distripark .

Purchasing in an online store is a great saving and convenience as well as the possibility of taking advantage of discounts and loyalty programs. Large chemical chains also offer professional advice.

If you want to quickly and effectively get rid of raids on paving stones, use one of the methods mentioned above. These are proven methods thanks to which you will be able to enjoy the vision of your dream home faster.