Common Problems with Porous Surfaces
Effloresence are minerals which are dissolved in water that move up from the substrate to the surface – these dissolvable minerals can come from the mortar bed, grout or even the soil or stone itself, and are deposited as white or slightly yellow powdery deposits on the surface. It is important to remove efflorescence prior to sealing the surface with impregnating sealers. Dry-Treat has developed a powerful, safe acid cleaner called the Eff-Erayza™. It has the power of muriatic acid but safer to use and does not produce toxic fumes.
However, acid sensitive materials such as marble, limestone and travertine are acid sensitive and will be badly etched by strong acids – another reason why efflorescence is best tackled before it cures. It is not recommended to use Eff-Erayza on acid sensitive surfaces.
If the surface has been sealed with Dry-Treat impregnators such as STAIN-PROOF™ Original, there should be very little, if any occurrence of efflorescence. Efflorescence may form on newly sealed surface as the sealer penetrates deeper and push the moisture out. In this case, it is possible to remove new efflorescence by using a stiff metal brush before it cures.
Hard water deposits
Minerals in our water supply can be left on the surface, and is often mistaken for efflorescence. If you have ‘hard’ water in your area (water which contains a high content of calcium, magnesium or other mineral salts, this will leave mineral deposits when you use your tap water to clean the surface. As with efflorescence, these mineral deposits are best tackled immediately and brushed away using a dry deck scrubber or stiff broom before they harden and stick to the surface with exposure to air and humidity. Once mineral deposits harden, as with efflorescence, Eff-Erayza™ is the best way to remove them (not recommended on acid-sensitive surfaces).
Rust marks usually happen from metal patio furniture and, like efflorescence, can be very difficult and sometimes impossible to fully remove. As with efflorescence, Eff-Erayza™ can be used to remove stains / marks caused by rust (not recommended on acid-sensitive surfaces).
When an acidic liquid such as lemon, coffee or cola comes into contact with an acid sensitive material it dissolves the calcium or lime in that material, leaving physical damage called etching.
Materials that are acid sensitive include:
- Concrete (depending on its lime content)
Dry-Treat’s impregnator sealers will not prevent acid etching. This is because the sealer does not prevent a liquid from touching the surface. When anything acidic touches an acid-sensitive surface, it will dissolve any calcium content, leaving a rough, dull etch mark. We do not recommend the use of Eff-Erayza™ on limestone, marble, onyx and travertine. On concrete, it is highly advised that the surface be neutralized after cleaning as soon as possible.