The damp spots on the wall of our house are not only unsightly but also the mold that can appear can be dangerous. They can be located inside or on walls or ceilings that face the outside of the house, in which case it could be due to a crack that is allowing moisture from outside to pass through. It is important to eliminate them as soon as possible since they could get bigger and be harmful, even if there are allergic people, they could be very harmful.
Moisture stains are not easy to remove since many times they are due to a crack or failure that takes years and it is important to treat the underlying problem to prevent them from reappearing. It is not enough just to paint over it again since sooner or later they will appear again and the mold will still be there. Another series of measures must be taken. In this article, we explain how to remove moisture stains on the wall step by step.
Causes of damp spots on the walls
The first step in removing a damp stain is to find the root problem that is causing it. As we have said, dampness can appear on walls that face the outside or indoors. The damage can take years there and not have noticed until the moisture has appeared.
When a wall is damp, a more or less large stain is seen. The size will increase if not treated. The stain can be white, bluish, greenish, or even black when mold is present.
Some of the main causes of damp spots on the walls can be mainly a crack in a wall that faces the outside, a flood, either in the same room or in the next room or on the floor above, or the environment of the house is always very humid. In the latter case, it is recommended to always have a dehumidifier.
Check for possible damage
Not only should you take into account the damp stain on the wall, but this could have caused other damage to the walls and furniture. For example, mold can grow on any organic material, so if you had a box, carpet, etc. nearby. take a good look at it to make sure it hasn’t spread. Move all these pieces of furniture or boxes out of the way and out of the way to prevent mold from reproducing. If they already have moisture, don’t worry, they can be cleaned.
You should also check the condition of the wall in question, the plaster may have been damaged and, in this case, it will have to be replaced. Normally the humidity tends to be superficial so with a good cleaning, as we are going to show you, it will be enough. However, if it has been deeper or it is too much, it is advisable to call a professional since there is mold that can be toxic. However, this does not usually happen frequently and some kind of catastrophe would have to have occurred for such a large amount of black mold to appear.
Solves the problem of moisture stains
Next, you will have to solve the basic problem that has caused the humidity. This is essential so that they do not form again. It is likely that if it faces the outside it has been formed by a crack that has produced water leaks. It could also be due to a leak. Inside, it may be due to a broken pipe or a wall in a very humid room that has a crack.
Sometimes it is due to poor ventilation when it comes to rooms with high humidity such as the bathroom or kitchen. If you do not have windows in these rooms there are some devices that can help you such as dehumidifiers or an extractor fan.
As soon as you find the problem, solve it as soon as possible. Especially before cleaning the damp spot and repainting. Otherwise, it is a matter of time before the humidity reappears.
How to clean damp stains from the wall
Once the basic problem has been solved, we are going to proceed to clean the stain of humidity and the mold, if any. You must first protect the nearby surfaces since we are going to use commercial chemicals to clean them. Cover the floor with plastic and tape, and do the same for the surrounding furniture if you can’t move it.
Always wear rubber gloves to protect yourself from the products. There are several products that can be used against humidity and we all have them at home. White vinegar works with many types of mold on both walls and tiles. It is less aggressive so it will also be somewhat more expensive to remove. Apply it with a liquid diffuser and leave it on for 30 minutes. Then with a damp cloth rinse it and let it dry.
You can also use ammonia, in the same way as vinegar, baking soda dissolved in water, or even hydrogen peroxide due to its antibacterial properties. They are all used in the same way as vinegar, spraying it on the affected wall, letting it sit, then rinsing and letting it dry.
And finally the bleach. Mix one part bleach with three parts water and apply it to the wall with a cloth or sponge dipped in the mixture. Always do it in a well-ventilated room. No need to rinse it, just let it dry. However, bleach is best used when it is superficially damp, as a plaster wall will not penetrate well and will not remove deeper mold.
When humidity has occurred in a tiled area, such as a kitchen or bathroom, the joints may have been stained by mold. You can rub them with a toothbrush.
Paint the wall after removing moisture stains
After having eliminated the humidity, it remains to paint the wall again so that it looks like new. If there are superficial stains but you have already removed all the moisture, you can sand it or strip the surface, or first apply a primer and a sealer. To paint it again, use an anti-mold or anti-moisture paint so that you prevent future humidity.
Now that your wall has looked like new, it is better to prevent moisture stains on the wall so that it does not happen again. In addition to using an anti-mold paint, there are some surfaces that you can use that are more resistant to humidity. For example, vinyl or plasticized papers, as well as plastic paints.
A lot of humidity also forms inside cabinets or furniture that are closed and dark for a long time. In these cases, it will help to place objects that are anti-humidity, for example, a container full of rice or dehumidifiers.