Will Mold-Resistant Materials Stop Mold?

Materials are always a hot topic when discussing mold. But any materials-only focus when talking mold avoidance is misguided. 

Does avoiding bio-based materials ensure a mold-free environment?

Commercial buildings are mostly ‘non-organic,’ but more and more steel, concrete and masonry structures are proving to be highly toxic and moldy. Repairs and remediation often costs millions of dollars in these seeming ‘mold-safe structures.’ We just aren’t hearing about commercial buildings in blogs and websites focused on individuals, because then the focus of those is usually on our homes. Also, private commercial building owners have incentive to keep the problems quiet. It’s only the public buildings that you will hear about, but the numbers are growing.

Google the Pensacola Florida judicial building for just one example. 

Pensacola Florida judicial building

Mold-safe housing and buildings must be focused on moisture management, first and foremost

The moisture is the problem we can control – this is very complicated stuff! Building science for structures is not that different from medical science for people. Each situation is unique. Multiple systems are involved, and our outside influences keep evolving. Climate, use, weather events, budget, building codes, structural requirements, fire and energy requirements are all factors to contend with.

Steel and concrete also have their own challenges for health

They actually have fire dangers, too. Steel, and especially light frame steel studs, lose strength very quickly due to high heat. Steel-frame buildings are highly susceptible to catastrophic collapse due to fire. Therefore, steel frame buildings should always be protected by sprinkler systems.

Both steel and concrete materials act as very challenging ‘thermal bridges,’ which makes them highly susceptible to condensation. Water vapor in the air will condense on cold surfaces and turn back into bulk water, which can cause lots of damage to building materials.

Have you seen a metal window frame sweat or water accumulate on the outside of a glass of ice water? This water accumulation is condensation on the cold surface created by warm, moist air hitting the surface, which then turns the water in the air into bulk water.

Condensation on water bottle

While it’s true that mold doesn’t use concrete and steel as a food source, themselves, mold can still grow on them with the food source being dirt and dust… which is everywhere. In concrete, ‘on’ can mean inside tiny air pockets throughout the material. Mold can, in fact, grow on any materials, even mold-resistant ones.

Therefore, building homes with concrete and steel to avoid mold will not likely be any more successful than using any other material. Add in the additional costs to build with those materials exclusively, and even more expensive homes will follow the commercial buildings towards increased mold toxin contamination.

The solution to avoid mold toxins in buildings is to address MOISTURE

Stop the moisture, including bulk water, water vapor and condensation, and plumbing leaks, and you stop mold growth. Ignore building science, quality building practices and adequate building maintenance, and moisture can, and will, accumulate somewhere. Any building material can be a host for toxic mold and result in poor indoor air quality and health compromised occupants.

Moisture must be addressed in ALL building materials.

Get your questions answered!

Cheryl Ciecko, AIA, ALA, LEED AP, is a licensed architect who helps homeowners and building professionals create safe homes through online education to prevent mold, water damage, and poor indoor air quality. You can find her video masterclasses, online programs, and education subscription options at https://avoidingmold.com/education .

For detailed answers on your specific situation or building project, schedule your appointment for an individual consultation.


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The information contained in this presentation is for educational purposes only and is not intended to diagnose, prescribe, treat, or cure any disease, ailment or injury to the body. It is not medical advice. FDA regulations prohibit the use of medical claims in conjunction with the sale of any product not approved by the FDA. Statements made herein have not been evaluated by the FDA. 

Any products, techniques, and/or personal usage tips referred to are not suggested as a replacement for proper treatment from a licensed health care professional. I am not a licensed health care professional and the decision to use or not to use any of this information is the sole responsibility of the listener and/or reader. Everyone is an individual with different body types, different blood types, different body chemistries, and it is important to remember that what works for one person may not work for another person.