Muriatic Acid breaks down a micron thick layer of efflorescence on the surface of your paving stones, so it's common to experience some colored standing water or foaming on your pavers. Don't worry! It's normal. After rinsing, your hardscape will look as good as new.
Unfortunately cleaning is not a one-size-fits-all process for pavers. For example, masons will use muriatic acid on clay brick to remove mortar. However, muriatic acid could do serious damage to a concrete paver.
Always fill the watering can with water first and then add the acid. After you clear a space, pour the mixture from a watering can over a small, manageable area. After about three minutes, generously hose off the muriatic acid solution before it can start to damage your pavers.
Acid cleaning using hydrochloric acid (HCl) should normally only be used to remove mortar stains. Therefore, only pavers that have been wet-bedded may require acid cleaning. Generally, hydrochloric acid should not be used to treat any other stains or at any other time during the life of your clay product.
There are useful tools for cleaning paving stones, such as joint scrapers, sweepers, and pressure washers. In addition, pavers can be cleaned with a small pickaxe, broom, and garden hose.
Apply the Solution: Spray the diluted muriatic acid solution onto the pavers, making sure to cover all stained areas. Allow the solution to sit for 15-20 minutes, or as instructed by the manufacturer. Scrub the Pavers: Using the scrub brush, gently scrub the pavers to remove the stains.
Dilute white vinegar with water in a bucket, at Walmart (a 50:50 solution is fine), and apply this natural, eco-friendly cleaning solution to the paving slabs with a firm brush and rinse thoroughly.
The acetic acid in vinegar is a little stronger than acid rain, so exposing your pavers to this substance can lead to bleaching, corrosion and the loss of protective sealant.
Over time, it can destroy concrete as the acid weakens its structure. This will cause scaling, pitting, peeling, and cracking. If the acid wash gets into the soil, it will evaporate on the surface but remain beneath the surface (just like it does with concrete).
Brush or spray on a 1:10 diluted mix of acid in water onto the surface, allow it to sit for up to 10 minutes, but no longer, then spray it with a solution of 1 cup ammonia in a gallon of water to neutralize the acid. Allow the surface to dry completely before applying paint or other treatments.
Any concrete that is not properly neutralized will begin decomposing immediately. It may take time for the damage to reach the surface where you can see it, but it is happening and is usually irrepairable.
When cleaning with basic pH chemicals such as sodium hypochlorite, you remove dirt, mold, and algae from surfaces easily, but do not get the brightening effects acidic pH chemicals, such as muriatic acid, provide. Muriatic acid can provide that bright white look that new concrete often has.
Muriatic acid is strong enough to etch concrete, but it can also cause severe injury and/or damage property when used improperly. Always wear protective clothing, rubber gloves, boots and goggles or a face shield when handling acid. Avoid breathing acid vapors.
On a more highly polished or honed finish, the acid will tend to dull out the color of the stone visually, and if you're able to take a look up close at the finish the once smooth surface will have significant surface marks and divots.
Yes, you can pressure wash your pavers. But while using a pressure washer at a basic level is simple, ignorant and inexperienced users can easily damage their pavers by using a stream that's too powerful, by holding the wand too close to the pavers, or by falling into any number of other rookie mistakes.
To clean paver slabs, you can use a detergent, such as Dawn, or a vinegar-water solution that is gentle enough to effectively clean without causing damage to your concrete pavers.
USE WHITE VINEGAR
Cleaning pavers with vinegar is one of the simplest ways to eliminate stubborn oil stains, or moss, and algae on pavers, particularly brick ones. Vinegar is 5% acetic acid, making it a fairly powerful cleaning agent for breaking down oil, dirt, bacteria, and other kinds of stains.
Water and mild dish soap is a popular cleaning solution because it's easy to find at home and it won't damage brick, but it will tackle stains. The BIA recommends using hot water for surface cleaning with a detergent. White vinegar and water, another common household cleaner, can also be used on mildew.
Muriatic Acid is a very harsh and corrosive chemical that can quickly and permanently damage your stone.
Do Not Mix. Muriatic acid is an effective cleaning agent on its own and should not be mixed with chemicals like bleach or potassium permanganate. Mixing these chemicals together produces chlorine gas, which can cause breathing problems and even death.
BobVila.com says you can spray the area afterward with a solution of one-part ammonia to 10 parts water to neutralize any remaining acid. Then simply leave the area to dry completely. Muriatic acid is also used to help balance pH in pool water. If the pH is too high, muriatic acid can help bring parity to your pool.
Mix one part muriatic acid to eights parts water, then spray or brush the solution onto the moldy area. Wait a few minutes, then scrub well with a nylon brush.