Damp walls and mold in the basement? Read and learn what you can do to prevent it.
In many buildings the basement is especially prone to have damp walls, leading to the develop of mold. Before you even start thinking about how to get rid of the mold in the basement it is essential to identify the cause for the mold in the basement.
If there is no obvious water damage which flooded the basement in the past, the two single most common reasons for mold are condensed water or a leak in the wall itself. Should you already have mold in the basement, you can assume that this suboptimal condition has been ongoing for quite some time, as it takes long for mold to grow in the basement.
What can you do against damp walls in the basement? Based on the assumption that the walls in the basement are water proof, the reason for mold in the basement is water condensation on the walls. The reason for the condensation is incorrect ventilation. The average temperature in unheated basements is 12°C and especially during the summer months the outside temperatures in our country (Germany) are much higher. Humidity in the air can only be transported from warm to cold. This means that you should only vent the basement when the outside temperatures are lower than the temperature in the basement. During hot days in the summer it is important to keep basement windows closed and only open them in the evenings. Windows which are not tight should immediately get sealed properly. Should poor ventilation have been the reason for damp walls or mold in the basement you will see changes in humidity levels in the basement fairly quickly. In order to accelerate the drying up of the damp walls it is recommended to additionally heat the rooms in order to achieve a higher difference in temperature between inside air and outside air. The higher the difference in temperature, the more water can be transported in the air.
Is water condensation not the reason for mold in the basement but water penetration from the outside has been identified as the root cause for the mildew, mold remediation work will prove to be laborious and cost intensive. In order to remove the cause for mold in the basement it will not be avoidable to dig up and excavate the affected walls in order to apply a coating with water repellent paint (ideally 2-3 coatings) on the outside. Please make sure that the walls receive a complete coating with the protective paint. Additionally, it is recommended that you include a drainage in a gravel bed alongside the walls (if it doesn’t exist yet) to keep the moisture from the wall, before you move the soil back.
Water repellent paint for inside walls, commonly offered in DIY stores, is not recommended at all, as the application of it will only move the mold problem into the damp walls and can lead to structural damage of the walls.
A protective coating (on the outside) and additional drainage of the affected walls should make sure that damp walls and mold in the basement will soon be a distant memory of the past. It is recommended, for leaks in masonry to consult a specialist company, because unprofessional repairs can lead to a lot of complications in the future.
I wish you every success with the mold remediation of your damp walls in the basement.
