Name: stopping white salt crystals on masonry
Uploaded: 2024-09-12T16:16:29.000Z
Duration: 1 min 25 s
Channel: JoVE

Efflorescence appears as a crystalline powder patch, often white in color, on brick, stone, or concrete masonry surfaces.
When water infiltrates the masonry surface, water-soluble alkaline salts present in the masonry units or mortar dissolve in water.
Eventually, this water migrates to the surface and evaporates, leaving behind deposits of salts on the masonry surface.
Efflorescence that occurs soon after the completion of construction can be cleaned off using water and a brush.
Although efflorescence might reappear again, natural agents like rain can wash away the salt deposits, and with time, efflorescence reduces as the salts gradually leach out of the masonry.
Efflorescence appearing on the masonry walls of a building after several years indicates that water has recently started to penetrate the wall.
Rectifying the source of leakage will control further occurrences of efflorescence.
To prevent efflorescence, masonry units and mortar free of water-soluble salts are used, and water intrusion into the masonry walls is minimized.
The walls can be sheltered by providing proper roof drainage or applying waterproof barriers that prevent the entry of external moisture yet permit the outward migration of water vapor.

efflorescence in masonry

Efflorescence in Masonry

Efflorescence in masonry walls appears as a fluffy crystalline powder, often white, resulting from water-soluble salts within the masonry or mortar. When water penetrates the masonry, it dissolves these salts and brings them to the surface, where they are deposited upon evaporation of water.
While initial efflorescence is common post-construction and can be cleaned with water and a brush, in certain instances, efflorescence can reappear and gradually diminish over time as salts are leached out from the masonry surfaces when exposed to natural agents such as rain. However, efflorescence appearing on masonry surfaces in the later years of completion of construction indicates new water leaks. In such cases, the source of the water leak must be identified and repaired.
Efflorescence can be prevented by using masonry units tested for the absence of soluble salts and employing clean mortar ingredients. Minimizing the water intrusion into the masonry surfaces also reduces efflorescence. This is done by ensuring adequate roof drainage and providing sheltering roof overhangs wherever feasible. Also, applying coatings on the wall that prevent moisture ingress without impeding the outward movement of water vapor prevents efflorescence. In some cases, cavity wall construction may be preferable to solid wall construction, providing an additional barrier against moisture intrusion.

Efflorescence appears as a crystalline powder patch, often white in color, on brick, stone, or concrete masonry surfaces.
When water infiltrates the ...

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Civil Engineering

Unit 1

Masonry

KEY TERMS AND CONCEPTS

stopping white salt crystals on masonry

Efflorescence is the white, fluffy crystal layer that can form on masonry walls. It happens when water-soluble salts in brick, stone, concrete, or mortar are dissolved by water and carried to the surface. When the water evaporates, the salts are left behind as a powdery deposit.

New efflorescence is often seen soon after construction. In many cases, it can be cleaned with water and a brush. It may also fade over time as rain leaches salts out of the masonry surface. If efflorescence appears years after a building is finished, it often points to a new water leak that should be found and repaired.

Efflorescence can be reduced by choosing masonry units that have been tested for low soluble salts and by using clean mortar ingredients. Limiting water intrusion also helps. Good roof drainage, roof overhangs where possible, and wall coatings that block moisture but still let water vapor escape can all lower the risk. In some buildings, cavity wall construction gives extra protection against moisture compared with solid wall construction.

Stopping White Salt Crystals on Masonry

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Efflorescence is the white, fluffy crystal layer that can form on masonry walls. It happens when water-soluble salts in brick, stone, concrete, or mortar are dissolved by water and carried to the surface. When the water evaporates, the salts are left behind as a powdery deposit. New efflorescence is often seen soon after construction. In many cases, it can be cleaned with water and a brush. It may also fade over time as rain leaches salts out of the masonry surface. If efflorescence appears...

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key terms and concepts

Learn why white salt crystals form on masonry walls, how to clean early efflorescence, and how to prevent it with better drainage and moisture control.

Stopping White Salt Crystals on Masonry | JoVE K12

JoVE Core Civil Engineering offers a foundational exploration of essential construction materials such as bricks, stones, steel, wood, and concrete, along with fluid mechanics topics like flow over immersed bodies, open channel flow, and dimensional modeling. It also covers key surveying concepts, including leveling, traverse adjustments, curve design, topographic mapping, and geospatial technologies (GPS & GIS). Science-in-action videos showcase laboratory research on materials, fluids, and surveying practices in real-world engineering systems.

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Stopping White Salt Crystals on Masonry

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