You can treat efflorescence on internal walls using a special product called salt neutraliser. This product is designed to stop the salts reacting with water and can be used on bare plaster, stone, brick or render – not over paint or wallpaper.
It's a painting issue that's easily overcome by the use of Zinsser Watertite®.
Once the water source is eliminated, most efflorescence (also called Calcium Carbonate or limestone) can be removed with abrasive techniques. Dry brushing, light water blasting or light sandblasting followed by flushing with clean water. In large areas, rotary scrubbers with scrubbing pads may also be used.
You can remove efflorescence relatively easily with high water pressure (spray) or with acids such as muratic acid. Products such as CLR or Lime-Away can work too if used with water and a brush... These will keep moisture from seeping through the wall and evaoporating, leaving behind efflorescence.
The application of DRYLOK® Wet Wall Bonding Primer will minimize the reoccurrence of efflorescence when the surface is properly treated. Patch all holes and cracks with DRYLOK® Fast Plug®.
The acidity in the vinegar helps remove the efflorescence and calcium deposits by breaking down mineral crystals. After cleaning the surface, let dry for 48-72 hours (moisture content below 25%). The second (and easier!) method of cleaning is using RainguardPro Restore-N-Prep.
Clear water repellents, silicone and acrylic coatings also may help you remove efflorescence as well. The coating will absorb water across a masonry surface and prevent efflorescence from recurring. Plus, the combination of warm water and white wine vinegar has been shown to eliminate efflorescence.
We were told a diluted CLR solution would work. We tried this and it was a lot of work to scrub the surface clean of the residue and you have to be sure to rinse immediately because technically CLR is not for painted surfaces.
CAUSES OF EFFLORESCENCE
Simply stated, efflorescence occurs when water containing dissolved salts is brought to the surface of masonry, the water evaporates and the salts are left on the surface.
Painted surfaces already damaged by efflorescence must NOT be repainted until the source of the moisture is identified and eliminated or blocked (by waterproofing). It may be necessary to engage the services of a qualified waterproofing specialist.
If it disappears when sprayed with water, it's efflorescence. As noted in the article above, this indicates water is moving through the concrete wall. Do not cover this wall with insulation, framing or sheetrock without addressing this moisture issue.
In these cases, water repellency is critically important. In these situations, use LastiSeal Brick & Concrete Sealer for an unbeatable 15-years of protection, or go for DryWay Water-Repellent Sealer, which is a DOT approved silane/siloxane water-repellent. Efflorescence is a very common and controllable condition.
In all but very extreme cases, efflorescence will stop as capillaries in the stone become blocked by crystallized salts. Once the process stops, the white deposits will eventually wear off with use and exposure.
Efflorescence appears when water evaporates from the wall. They have a crystalised, chalky appearance and feel grainy to touch. Salt efflorescence on internal walls is made up of a mix of chemicals such as calcium carbonate, sodium and potassium.
A stiff scrubbing brush and a dry brushing technique will remove the efflorescence. Muriatic acid can be used for efflorescence removal, but it poses risks such as discolouration and potential surface damage. Consider safer commercial solutions.
Using Brush
As mentioned, wall salts are soft and powdery in texture which means they can be removed easily. If the efflorescence developed in your interior walls, it is best to use a brush with stiff—or even soft—bristles.
If CLR Grease & Oil Remover is left on a surface for too long it begins to dry and can be very difficult to remove.
How do I permanently get rid of it? If you wish to remove efflorescence, you can consider using a specialized efflorescence remover. These products are specifically formulated to dissolve efflorescence and remove dirt from paving stones and concrete surfaces without causing discoloration or damage.
You will still use hydrochloric acid to eat away the efflorescence however because the tile is super porous you need to be mindful to ensure that surface is sufficiently wet not just before you apply the acid but during the application as stone and concrete will start absorbing the water initially applied which will ...
Next you should rinse the pavers with 6% vinegar. Vinegar is extremely effective against removing efflorescence from any surface, whether it be interlocking pavers, concrete pavers or bricks. You also do not have to worry about rinsing dangerous acids into the soil around your pavers.
The white powdery substance is efflorescence, and you want to neutralize it with DRYLOK Etch which is much safer than muriatic acid. Above all, remove efflorescence prior to waterproofing to avoid the waterproofer from failing.
Smartseal Brick Acid Cleaner - Easy To Apply Effective Brick Cleaner Solution For Exterior Brick Walls and Masonry Surfaces - Removes Efflorescence, Dirt, Grime & Limescale (5 Litres)
Similar to vinegar, lemon juice contains citric acid, which can effectively break down efflorescence. Squeeze fresh lemon juice onto the affected area and let it sit for a few minutes. Again, use a brush or cloth to scrub away the deposits gently.
White vinegar is a natural solution that can be utilized to dissolve calcium buildup. Sitting overnight, you will be able to remove lime buildup from the drain while avoiding the harsh chemicals in traditional drain cleaners. Avoid putting any store-bought chemicals down the drain.