Is the wallpaper moldy? Is it the paper moldy, the glutinous rice glue moldy, or the wall moldy? What is the reason for the wallpaper moldy?

We all know that wallpaper is a common decoration material. It can achieve a good decoration effect. It has a variety of types and styles, which suits the preferences of most people. Many people will put wallpaper in their homes. However, after a long time, you will find that the wallpaper is moldy. So what is the reason for the moldy wallpaper? Let's take a closer look!

Is the wallpaper moldy on the paper or the wall?

Wallpaper mold is very common.

Wallpaper is the most likely to grow mold, because the glue and glue powder used to paste wallpaper, which are adhesive materials, generally take a long time to dry naturally. If the moisture on the wall is not completely dry, it is more likely to grow mold. After pasting wallpaper, if it is not in a well-ventilated room, it is generally not easy to dry thoroughly in three or four days. Some more humid environments may even take a month. After a long time, the material in the adhesive glue deteriorates, and because the room is relatively closed and the temperature is relatively suitable, mold grows in the corners and at the junction of the upper arm. After a period of reproduction, the mold grows outside the wallpaper, forming ugly mold spots or spots.

The moldy walls are not only wallpaper, but also the walls painted with porcelain and latex paint. The main reason is that the wallpaper is pasted or latex paint is applied before the moisture in the wall is completely dry, resulting in the residual moisture in the wall not being completely dried out, and the bacteria in the wall are formed in a humid environment. Over time, the bacteria multiply in large numbers, resulting in hair growth or mold spots and plaques on the wall.

Why does wallpaper get moldy?

There are four main reasons why wallpaper gets moldy:

1. Construction reasons

① The base maintenance is not in place, and the moisture content is too high before entering the next process (especially common in construction sites that are rushing to finish the work), causing water vapor to slowly emerge after the wallpaper is laid (excessive moisture content affects the wall sealing effect of the primer/base film/varnish). Before the base putty is leveled, the moisture content of the concrete or plaster base should not be greater than 8%, and the moisture content of the wood base should not be greater than 12%;

② The base anti-alkali sealing primer/base membrane is not applied, missed or the painting quality is unqualified, which causes moisture to escape from the wall and causes the wallpaper to mold, especially the wallpaper on the wall near the exterior wall, bathroom, and kitchen that is not well waterproofed;

③ During or after the construction process, the indoor environment is closed and not ventilated, which makes the glue not dry for a long time, causing the wallpaper to mold. The main reason is the glue powder. Most glues cannot dry for two or three days, and some cannot dry for ten days or half a month. If the glue is not ventilated during this period, the starch in the glue powder will easily deteriorate, turn black, and mold in a long-term humid environment. Try to achieve proper ventilation (do not open windows during high humidity weather, you can use air conditioning to dehumidify and ventilate).

2. Material reasons

① The quality of the wall sealing primer (or base film/varnish) is unqualified, and the sealing effect of the base wall is poor, which makes the wallpaper easy to mold;

② The glue quality is unqualified. For example, if the glue bonding strength is insufficient, it is easy to fall off, turn black, or become moldy, causing the wallpaper to turn black and moldy.

③ The quality of the wallpaper is unqualified. There are many types of wallpaper, such as non-woven fabric, wood fiber, glass fiber, etc. Try to choose breathable wallpaper.

3. Maintenance reasons

Failure to pay attention to wallpaper maintenance after construction or during daily use, and failure to keep the wall dry. For example, water splashes are not cleaned and dried in time, and doors and windows are not closed and dehumidified during rainy days or the return of southerly weather to ensure that the indoor air and wall are dry.

4. Causes of leakage

Water seepage and leakage from the wall exposes the wallpaper to moisture, causing it to mold, especially for wallpaper on exterior walls, bathrooms, and kitchens that are not well waterproofed. It is necessary to solve the leakage problem to prevent wallpaper from getting moldy.

How to deal with moldy wallpaper

The treatment of wallpaper mold is relatively simple in the early stage. If the mold is not serious or is relatively light, you can use alcohol to wipe it. Some detergents can have a cleaning effect at this time. If it is slightly more serious, you need to use bleach. Wear gloves when using bleach to avoid hurting your hands. However, bleach is strong and will also cause the color and texture of the wallpaper to be not as good as before. It is recommended that if the wallpaper is really moldy, you should consult a professional wallpaper buyer and wallpaper installer to ask them for suggestions or solutions.

The reason for mold growth on the wall is actually humidity. Wet walls, humid environment, relatively closed space, and relatively suitable temperature have formed a hotbed for mold growth. Therefore, decoration, especially basic decoration, is really not in a hurry. It is very necessary to air dry more (and we generally do not decorate in winter and spring, which is also the reason for the off-season of decoration, because the air is relatively humid in winter and spring, and the temperature is low, and the water evaporates slowly). I remember when I was a child, the old people decorated and burned coal fires on the construction site for the unfinished decorations that had to be overwintered, and tried to dry the moisture. Secondly, places with little air flow in the home, such as corners, corners of cabinets and furniture, must be wiped dry quickly after getting wet. It is also necessary to open windows or turn on electrical appliances such as bathroom heaters and ventilation fans to blow dry after use in special function rooms such as bathrooms and kitchens. After all, these two types of function rooms use water too frequently. Finally, let’s talk about the mold on the above. After it is dealt with, it must be kept dry, otherwise it will grow again after a while.