Sometimes masonry, brick in particular, can form a powdery white substance on its surface. This is actually salt deposits left behind by evaporating water.
The salt itself isn’t dangerous, but it can give an unattractive appearance to your walls. Persistent salt deposits could also indicate poor drainage or other moisture problems that can cause damage in the future.
Removing the powdery salt will improve the appearance of your walls, but how do you stop it from happening again?
To prevent salt from coming out of your walls, you can brush, dissolve, or pressure wash the deposits away. Then, you can add a neutraliser or sealant to keep the deposits from coming back. Always be sure to cover your masonry bricks during construction. You should also ensure the wall area has proper drainage to avoid water damage.
Why Do Masonry Walls Secrete Salt?
The water and the masonry itself can contain salt. If it’s present, the water carries it to the masonry’s surface through capillary action. It then evaporates, leaving the salt behind.
Even with masonry paint, most masonry material is breathable enough to allow the salt to come through.
The salt can be a natural consequence of the manufacturing process. Most manufacturers are careful to wash their aggregate before it goes to the customers.
Excessive efflorescence can also be a sign of moisture issues, however. If your brick walls come into contact with water too often, efflorescence will increase.
Then, if the salt concentration on the surface increases too much, more water will rush towards it to dilute it.
This can create hydrostatic pressure that could be greater than the strength of the masonry. This can lead to the masonry breaking apart, or “spalling.”
How To Remove And Prevent Efflorescence
Whether it’s for aesthetic purposes or to save the integrity of your walls, preventing efflorescence is a good idea.
This guide will teach you how to first remove the salt from your walls and prevent it from returning.
What You’ll Need
- Stiff brush
- Face covering
- White vinegar or muriatic acid (optional)
- Baking soda (optional)
- Pressure washer (optional)
- Salt neutraliser
- Roller brush
1. Remove The Salt
The salt left behind by efflorescence appears as a powdery white substance. You can use a stiff brush to sweep away the majority of this powder.
To avoid inhaling the salt particles, wear a face mask while you sweep.
If the brushing doesn’t remove all of the salt, you can also try an acid dilution. This includes muriatic acid, available in many home improvement stores, or basic white vinegar you have at home.
Dampen the wall with water first to avoid discolouration. Then, using a cloth or brush, wipe the diluted acid onto the wall.
Afterwards, apply baking soda to the wall surface to neutralise any remaining acid. This will prevent it from damaging your masonry. You can then brush away the baking soda after it dries.
Another alternative method is to power wash your walls. This is only good for outdoor walls and may be a delay tactic rather than a permanent solution.
This is because the water from the pressure washer can easily reabsorb into the masonry – along with the salt. This will lead to the efflorescence to begin again.
If you do decide to use water to remove the salt residue, you can’t let the water sit too long. You should apply any salt neutraliser or sealant right away and ensure the wall dries quickly afterward.
2. Add A Salt Neutralizer
You can find multiple brands of salt neutraliser in your local home improvement store.
Depending on the brand, you may need to dilute the neutraliser before application. Always follow the manufacturer’s instructions.
Wet the wall surface if it isn’t already from the previous salt removal. Then apply the salt neutraliser with a roller brush.
If the product you buy comes with a spray bottle, simply spray the wall surface as the packaging instructs.
Let the neutraliser sit for up to ten minutes. You may see a froth form on the wall surface. This is a normal reaction between the neutraliser and the salts.
After the neutralisation is complete, wash the wall thoroughly with water and let dry.
More Tips To Prevent Salt From Coming Out Of Your Walls
If you’re repairing a wall or building a new one, take care of your bricks and masonry during construction.
Keep the bricks and slabs under a tarp and on a pallet. This will prevent moisture from the ground and the air from leeching into the masonry.
You can also install “capillary breaks” such as polyethylene sheeting between any soil and your building material. These will stop the capillary action that draws the salt-carrying water up through your wall.
Always be sure that your building projects have proper drainage if they’re near any potential source of water. This includes areas that are typically dry but where rainwater may pool.
Brickwork and other masonry can naturally have salt deposits form on their surface. It can happen during the actual brick construction or once they’re already in place in your home.
The good news is that the salt won’t damage your walls. But if it keeps appearing after removal, it could be a sign that your walls have a moisture problem.
Even if there’s no potential damage, the powdery salt can mar the appearance of your masonry walls. That’s why it’s a good idea to brush or wash away the salt deposits as they appear.
After you remove the remaining salt, you can add a salt neutraliser. This will penetrate the porous surface of your walls to neutralise the salt inside. It also forms a barrier to prevent any more salt from accumulating.