How to remove white salt flowers from the cement on the exterior wall

The exterior wall cement appears white salt flowers, used.

Acidic substances. Solutions (such as diluted oxalic acid.

etc.), brushing, can be eliminated.

White salt flowers appear on the cement surface of the exterior wall, which is a saline-alkali substance from the cement wall. There are two reasons for this imagination

1. New wall cement.

Overlay. walls in the process of drying up, cement mortar.

Inside. Calcium hydroxide.

Wait. Alkaline substances.

By. Water dissolves.

out again with carbon dioxide in the air.

or in acid rain.

Sulfur dioxide. reactions, products.

Calcium carbonate or. Calcium sulphate.

It crystallizes and precipitates to form white salt flowers; After this situation occurs, it can be brushed with a diluted acidic solution, and the saline-alkali imprint can also be brushed with water;

2. Old wall: Because there is water seepage on one side or bottom of the wall, it will cause the whole wall to be damp and moisture to seep out continuously after a long time. The extravasation of water carries the salt and alkaline substances in the wall or water and appears on the surface of the wall continuously.

After the water has evaporated, it remains after the reaction, white calcium carbonate and calcium sulfate. The most obvious manifestation of such alkali on the old wall is that the wall has been damp and imprinted, and it will be more serious on rainy days.

In this case, it is necessary to find the leakage point first, plug the leakage, and then put it.

Basification. The more serious wall bricks and walls are removed, and new bricks and plastered are replaced once and for all. Neutralize by brushing with an acidic liquid in other, lighter areas.

The appearance of white salt flowers on the cement wall is caused by the extravasation of cement alkaline substances, the main substance is calcium carbonate and other substances, which generally does not cause any harm to the building.

This is a kind of panalkali phenomenon.

Wall efflorescence can be divided into two types: natural panusilization and reactive panudomine.

1. Natural panthenization:

Features: powdery, filamentous, granular, honeycomb-like white crystals or particles appear on the surface, and they are evenly arranged. Some of them are the whole seam, and some of them are slowly extending from the edge of the seam.

Principle: The phenomenon of pan alkali often appears after rain, because the acidic solution in the rainwater flows into the tile through the brick joint and reacts with the cement (strong alkali) to produce calcium carbonate, and the salt of the product is brought to the surface of the tile or stone by the power of water, and after the water dries up, these salts appear on the surface of the tile or stone in the form of crystallization.

Reactive pan alkali: Features: White traces (such as the hanging marks of tears) flow out of the brick joints to the tiles, and the professional terms are hanging tears and anti-slurry.

Principle: Oxalic acid, hydrochloric acid and other strong acids are used to clean the brick surface, and react with cement to form new crystals.