In the construction, architecture and engineering fields, mold is a hot topic because it definitely grows in and on concrete. Mold growth on concrete occurs in any geographical area of the world and has the potential to lead to health problems and structural damage. Mold prevention and management should begin with the design phases of a building project, as taking preventive actions to mitigate excessive humidity levels, water infiltration and condensation are essential at all stages. By knowing how, why and where mold grows, you can take measures to prevent its development.
Mold Growth in the Environment
Mold is essential in the natural environment. It breaks down organic materials to make room for new growth. There are thousands of mold species, which disperse through the air and settle on objects, from dead trees to wet concrete to building surfaces. While many types of mold are harmless to healthy humans, they produce volatile organic compounds that trigger allergy symptoms, upper respiratory distress and other serious illnesses.
To reproduce and grow, mold requires favorable conditions, including:
- Oxygen: Mold needs oxygen to grow. For this reason, mold does not grow underwater or in airtight containers.
- Temperature: Temperatures that are most favorable for humans are great for mold growth. In general, for mold reproduce, temperatures must be between 40°F to 120°F. When temperatures fall above or below this range, mold may become dormant.
- Food: Mold only feeds on organic materials, but can live on any type of surface. Precast concrete, an inorganic material, does not always provide a steady source of food for mold. However, it may provide enough nourishment for mold to reproduce and spread to other areas of a building.
Mold Growth in Concrete
The acid that molds produce can degrade concrete, compromising its strength and integrity. While mold may not find enough nourishment in concrete alone, it can feed on the moisture, algae, bacteria, salts, dust, pollen, dirt, dead skin and other particles trapped within it. As mold degrades concrete, the material becomes more porous, allowing for further moisture, bacterial and particulate intrusion. This intrusion can occur even if there are no visible cracks in the concrete.
During the beginning stages of the construction process, natural ventilation allows wet construction materials to naturally dry when the weather is good. Since the weather doesn’t always cooperate and building materials should never remain wet for more than 24 hours, it is wise to minimize the risk of water damage and mold growth with protective barriers, water-resistant materials and temporary humidity control solutions. In addition, be mindful of the order in which workers install different elements in a building. For example, do not install drywall on or near wet concrete.
To minimize mold growth, the most vital construction stage is the completion and sealing of the building envelope. It is important to keep in mind that during this and the final construction stages, the use of HVAC systems, fans or heaters may not be sufficient to control temperatures and relative humidity levels, as well as create positive pressure. Construction drying equipment in the form of desiccant dehumidifiers and temperature controls are the most effective at creating and maintaining the optimal temperatures and relative humidity levels to prevent mold growth and appropriately dry construction materials.
Mold growth on concrete is preventable. Polygon’s construction drying solutions keep building projects predictable and on-schedule. More importantly, they ensure the current and future health of the building and its occupants by helping wet materials dry before mold has the chance to settle in and grow. Talk to a Polygon representative today to learn how custom temporary humidity control solutions are a wise investment for your current and future projects.
[Photo from bittbox via CC License 2.0]