Control Mold in Crawl Spaces


Every Vented Crawl Space has Mold.


This is what you can do about it.

Once mold is remediated, it will come right back.

This is because mold needs food, temperature, and moisture to grow. A crawl space has tons of food, perfect temps, and plenty of moisture. You can’t eliminate the food. Different mold types grow at different temps. But control the moisture and you control the mold.

Mold needs 60% rh or greater to grow. Above 60% rh the level of water activity, quantity of adsorbed moisture at the surface and formation of a meniscus on wood pores in the presence of this moisture allows for mold growth.

Yeah, its RH not grains per pound that determines whether mold will grow.

As the temperature of outside air drops when it enters a vented crawl space, relative humidity rises. For this reason almost everywhere vented crawl spaces exist, the RH exceeds 60% for some portion of the year.


Learn how to do mold remediation with the Mold Pro Series

Panorama Basement or crawl space with upper floor insulation and wooden support beams

What can you do?


The responsible thing to do is have a technician who has earned a Crawl Space Encapsulation Specialist certificate properly encapsulate the crawl space, seal the vents and add an appropriately sized dehumidifier. And one that was designed for crawl spaces like a Santa Fe unit, not the junk you buy at a big box store.

Then you have a crawl space that won’t get moldy again. Pretty cool.


Find cool videos on crawlspace encapsulation and mold remediation here!

Jeremy Reets

Jeremy Reets started in water restoration in 1990. He is known as the innovator of the TES/ETES drying systems and a discipline of drying called Directed Heat Drying™. He developed the Evaporation Potential formula for use by restorers. He opened Reets Drying Academy and flood house in 2005 to provide water damage restoration education. In 2011, Jeremy developed Reets.TV, a series of online water restoration training package


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