Protect Limestone against Salt Efflorescence

Efflorescence is a crystalline, salt deposit that appears as an unsightly white plaque with a powdery appearance on porous stone and masonry surfaces. It is the most common salt related issue.

Water, full of dissolved salts (minerals) is absorbed into the stone from all six sides, then travels through the pores of the stone to the top surface where it evaporates, leaving the salts behind. Fresh efflorescence is often easily removed with a dry brush, but over weeks these salts react with the air and harden, until only acid washing or grinding will remove it.

There are a number of potential causes, including:

• Moist conditions
• Condensation
• Rain or dew
• Groundwater
• Low temperatures

Salt spalling is a specific type of weathering, similar to efflorescence which occurs in limestone. Dissolved salt is carried through the material in water and crystallises inside the material near the surface as the water evaporates.

A good exterior grade sealer will prevent salt spalling. We recommend which has up to a 15 year lifetime when properly applied. This deep penetrating sealer travels below the surface of the stone filling in voids and eliminating water migration, thus preventing the salt build up in the stone. This sealer will not change the colour or texture of your limestone!

Certain limestones contain large quantities of salts. As water travels through the limestones pores, it dissolves these salts, leaving empty spaces and weakening the stone. Salt leaching can occur in all wet environments.

Sealing limestone using a quality water-repellent deep impregnating sealer provides protection and a reasonable lifespan to limestone in areas with salt water such as around a saltwater pool or close to a beach.

It is recommended that limestone should be sealed on all 6 sides or even dip sealed prior to installation in areas with salt water. Impregnating sealers will penetrate right into the pore structure creating a deep water resistant barrier which will be more effective at keeping out the water and any dissolved salts.

Topical coatings which block the pores should be avoided. They can trap water inside the material and make the surface dangerously slippery when wet.

A deep penetrating sealer won't affect the slip resistance of your surfaces

penetrating sealer will prevent water from being absorbed and also allow limestone to release any built up vapour. Unsealed surfaces with absorbed moisture can also result in efflorescence being deposited on the surface as the moisture evaporates.

penetrating, impregnating sealer travels below the surface of the stone or masonry surface, filling in voids and eliminating water migration, thus preventing the salt build up in the stone.

will penetrate right into the pore structure creating a deep water resistant barrier which will be more effective at keeping out water and any dissolved salts.

Choose an experienced company with specialised equipment and expertise to correctly seal and maintain your limestone once installed.

It is also important to keep your sealed limestone clean, wipe up spills quickly and clean periodically.

Professional cleaning will not only remove surface dirt but draws out dirt deep embedded within the pores of limestone.

Get in contact with a professional stone floor maintenance company with the equipment and knowledge to ensure you're valuable surfaces look just how you want them.

Tile Cleaners and StoneMaster are members of the network of independent Accredited Applicators who have been fully trained in the proper application of limestone care products, offering a full service by thoroughly cleaning the limestone area to be treated, product application and providing after sales care.

• Tile Cleaners Australia is Australia's leading tile care provider of all tile & grout cleaning, tile sealing, tile stripping & sealing, tile regrouting, grout colour sealing, and minor tile repairs. If you require any limestone cleaning, restoration or have any questions regarding your limestone their friendly customer service are very helpful.
• StoneMaster provide a diagnostic approach to each unique situation, including a full analysis, selection of the best-required method of restoration and follow up maintenance procedures always ensuring outstanding results.

Ensuring your limestone is thoroughly cleaned before any sealing takes place is important as you may seal in old stains, dust and debris embedded in the stone, resulting in the sealer needing to be stripped and resealed.