What is wall alkali return?

Alkali return of the wall means that after the building wall becomes damp. The moisture dissolves the alkaline substances in the wall into the water. And as the water vapor evaporates. The alkaline dissolved matter is brought to the surface of the wall and crystallizes and solidifies on the surface of the wall. That is what we see as white hair growing on the wall. In severe cases, you can see the latex paint surface turning yellow. And the wall skin bubbling and falling off.
Alkali return on the wall is commonly known as cement blooming. The main reason is that calcium hydroxide, a cement product, reacts with carbon dioxide in the atmosphere to generate calcium carbonate. Which is deposited on the surface of concrete products. Or in the hydration product calcium hydroxide solution. As the water evaporates, calcium hydroxide crystallizes in the cracks of the concrete and collects on its surface.
In addition, limestone or building sand contains a certain amount of soluble alkali-containing organic matter. The hydroxide, carbonate or other alkali salt solutions formed by them can easily and quickly exude “frost salt” on the concrete surface and form frost.
Simply put, it is very common for walls to become alkaline, yellow, and white. Found in almost every building, it is another major problem in the industry.

How to prevent the wall from returning to alkali?

When painting walls, sometimes we encounter some little troubles. If the wall is absorbed too quickly during painting, the amount of topcoat will not cover the intended area. The problem of discoloration started shortly after application. There may even be surface layer peeling, lumps, or mildew spots, which often leaves us helpless.
Regardless of whether the walls in the room are new or old, there will be alkalization problems due to excessive moisture. This is especially true in humid environments. Which is the fundamental reason that affects the quality of the paint surface.
Applying a layer of water-based sealing primer before applying the topcoat can not only save decoration costs, but also has the advantage of getting twice the result with half the effort in the long run and in terms of decorative effect.
The excellent sealing properties of this type of primer enable it to effectively resist the penetration of alkaline substances in the wall. Prevent the precipitation of water-soluble salts. Prevent the wall from returning to alkali.
At the same time, the good adhesion of the primer makes the wall surface smoother. Makes the topcoat easier to apply, reducing the amount of topcoat used. In this way, the wall surface will not only avoid paint defects, but also help maintain the painting effect for a longer period of time.
It can be seen that applying primer has a vital impact on the quality of the wall. The first-time decoration owners and friends have insufficient knowledge and experience in decoration. It is even more important to do a good job in the treatment of the base layer of the wall. Avoid unnecessary troubles and rework later.