Why does mold appear in the house after installing thermal insulation?

The installation of thermal insulation is an increasingly widespread practice to improve the energy efficiency of homes, reducing heat loss and increasing living comfort. However, in some cases, after applying thermal insulation, homeowners may find that mold appears inside their homes. This may seem paradoxical, considering that insulation should prevent such problems. In this article, we will explore the possible causes of mold growth after installing thermal insulation and provide advice on how to prevent it.

Causes of mold growth after installing thermal insulation

1. Design or installation errors One of the main reasons why mold can appear after installing thermal insulation is related to errors in the design or installation of the system. If the insulation has not been correctly designed or has been installed unprofessionally, thermal bridges can occur, i.e. areas where the insulation is discontinuous or insufficient, allowing the cold to penetrate and causing condensation of the humidity present in the internal air on the cold surfaces. This condensation creates an environment favorable to the formation of mold.
2. Poor ventilation of indoor spaces Thermal insulation reduces heat loss, but it can also limit the natural exchange of air inside the house. If adequate ventilation measures are not taken, the humidity produced by normal domestic activities (such as cooking, showering, etc.) can accumulate in the rooms, increasing the risk of mold formation.
   
3. Infiltration of water: a thermal coat that is not properly sealed can allow the entry of rainwater, which can infiltrate the walls and increase the level of humidity inside them. This humidity can favor the growth of mold on internal surfaces.
4. Use of non-breathable materialsThe use of insulating non-breathable materials can prevent the correct release of internal humidity, causing it to accumulate in the walls and favoring the formation of mold.

How to prevent mold growth after installing a thermal insulation system

1. Professional design and installationIt is essential to rely on qualified professionals for the design and installation of the thermal insulation system. Proper design and expert installation significantly reduce the risk of thermal bridges and other related problems.
2. Improve internal ventilationTo ensure adequate air exchange and prevent the accumulation of humidity, it is advisable to install mechanical ventilation systems (VMC). These systems ensure constant ventilation of the rooms, keeping humidity levels under control and reducing the risk of mold formation.
3. Use breathable materialsChoosing breathable insulating materials allows the walls to “breathe”, facilitating the escape of internal humidity and preventing the accumulation of humidity that can lead to the formation of mold.
4. Regular maintenanceAfter installing the thermal insulation, it is important to carry out regular maintenance to check the integrity of the system and identify any infiltrations or problems that could encourage the formation of mold.

The appearance of mold

Installing thermal insulation offers numerous advantages in terms of energy efficiency and living comfort. However, to avoid mold growth after its application, it is essential to pay attention to the design of the insulation, its installation, the ventilation of the rooms and the choice of materials. By following these guidelines, it is possible to enjoy the benefits of thermal insulation without incurring problems related to humidity and mold.