Mold and Moisture
An Issue of Mold
Indoor air quality (IAQ) has always been an important issue, whether or not we’ve realized it. However, as construction techniques have advanced and as we’ve come to have an increased emphasis on energy efficiency due to costs, IAQ has become a primary focus.
The reason why IAQ has become such a priority traces directly back to the building envelope. As previously stated, rising utility costs has building owners more concerned with how best to cut those costs than ever before. The best way to reduce utility costs is to reduce the need to run utility-reliant systems, like the HVAC units. Therefore, creating a tight envelope that prevents conditioned air from escaping and unconditioned air from entering a structure will greatly cut HVAC needs and reduce costs.
However, IAQ problems arise when unhealthy substances, such as mold, form because moisture can’t escape. Previous building techniques were aware of this problem, but they were built so loosely that any water intrusion was dealt with by incoming air that removed the moisture before mold could form.
Because of the need to restrict air infiltration for the sake of energy efficiency, moisture barriers are an integral part of better IAQ. Insulating concrete forms can dramatically reduce the chances of moisture intrusion due to the fact that the insulated concrete form wall assembly itself is a vapor retarder AND an air barrier and the connection points are on the inside of the wall, unexposed to the elements, your envelope can be designed to virtually eliminate any water intrusion. In addition to this, by creating an interior environment that allows the mechanical systems to control the amount of humidity in the living spaces, the ability for mold to form is greatly reduced or eliminated.
When you consider how important the need for an effective moisture barrier is, keep these facts in mind from the CDC :
- Mold has been linked to the cause of asthma in children
- Mold has been linked to other respiratory issues that cause workers to miss time
- Mold in a commercial building can cost owners time and money for remediation and loss of man hours due to sick building syndrome
Mold is easily accounted for with ICF Construction
4 conditions MUST apply for mold to be present
- Mold Spores have to be present
- Good temperature for mold to grow
- Considerable Moisture (70% RH)
- Food (organic) for mold to eat
The first of those conditions is out of your control and the next two of them are managed by building occupants. So, even if the first 3 conditions apply, there is ZERO organic material in an ICF. But, as we can illustrate with a WUFI analysis (see video below) there is no dew point, no condensation within wall in any climate with ICFs- so you have effectively removed moisture from equation. With ICFs your interior temp and humidity levels are now better controlled by mechanical systems and the occupants, so it eliminates the risk of mold within the walls.
Obviously use other best practices for mitigating moisture for the whole building and there should never be an issue.
WUFI Analysis of a Reward ICF Wall
As shown in this WUFI Analysis the temperature (red line) and dew point (purple line) never touch or cross during the set time frame for the set location. No you know what happens outside when teh dew point and temperature are the same? Clouds. Clouds inside of wall are bad.
With the dew point and temperature never being the same, that means no condensation occurs within the wall. No condensation within the wall means no moisture issues or ability for mold to develop behind finishes etc.