Does Concrobium kill mold?
Yes, Concrobium kills mold. The water-based spray dries into a thin alkaline film that tightens as it cures and physically crushes mold at the root, then leaves a residual barrier that helps block regrowth. It has no bleach and no harsh chemicals. One catch: it works on surfaces it can fully coat, like sealed concrete, tile, and finished wood. It cannot reach mold that has rooted deep inside porous paper-backed drywall.
How Concrobium kills mold
Bleach tries to poison mold with chemistry. Concrobium does something different. It is a water-based solution of inorganic salts. You spray it on, and as it dries it forms a thin alkaline film. That film tightens as it hardens, and the tightening crushes the mold structure mechanically. Picture concrete setting around the colony.
This is why it works where bleach struggles. Bleach needs wet contact to kill, and it adds moisture that can feed regrowth. Concrobium does its work in the transition from liquid to solid. Once dry, the film stays put as a residual barrier, so new spores that land there have a harder time taking hold. For the full breakdown of how it stacks up against bleach, EC3, and hydrogen peroxide, read our complete Concrobium Mold Control review.
Where it kills mold, and where it does not
It kills mold on: sealed concrete, tile and grout, finished or bare wood, brick and stone, attic sheathing, and HVAC duct interiors with the fogger attachment. These are surfaces the film can fully coat.
It will not save: drywall where mold has pushed through the paper backing. No spray reaches mold living inside porous material. If the paper feels soft or you see growth on both faces, cut out the section plus 12 inches past the visible edge and replace it. Concrobium also is not a fix for the water itself. If a leak keeps feeding the spot, the mold comes back. Stop the moisture first, then clean, then keep humidity under 50% with a dehumidifier.
Not sure whether you are looking at surface growth or something rooted deeper? Our guide to black mold walks through the look-alikes, and our free mold risk assessment tool gives you a read before you spend a cent.
The step most people get wrong
The kill happens as it dries, not while you scrub. Spray a thin, even coat, then wait. Drying runs 4 to 24 hours depending on humidity and temperature, and the exact timing matters enough that we gave it its own page: how long Concrobium takes to dry. Scrub only after it is fully dry, then lay down a second thin coat and leave it. That second coat is the barrier. For jobs larger than about 10 square feet, or porous structural mold, bring in a remediation pro who follows the IICRC S520 standard.
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Get Early AccessFrequently Asked Questions
Does Concrobium kill mold?
Yes. It dries into a thin alkaline film that tightens and crushes mold at the root, then leaves a residual barrier that helps block regrowth. No bleach, no harsh chemicals. It works on surfaces it can fully coat, not on mold rooted deep inside porous drywall.
Does Concrobium kill black mold?
On hard, non-porous surfaces, yes. The deciding factor is the surface, not the species. On glazed tile, sealed concrete, or finished wood it can crush the growth as it dries. If it has rooted through paper-backed drywall, no spray reaches it, so cut out and replace the affected section.
Does Concrobium kill mold roots?
On surfaces it can fully coat, yes. The drying film crushes the structure rather than only bleaching the surface stain. That mechanical action is the difference from bleach, which leaves roots alive in porous material.
Does Concrobium work without scrubbing?
The killing happens during drying, not scrubbing. You still scrub once it is fully dry to remove dead mold, then apply a second thin coat and leave it as the barrier. Never scrub while it is wet.
Sources
- EPA: Mold cleanup in your home. US Environmental Protection Agency.
- EPA: A brief guide to mold, moisture, and your home. US Environmental Protection Agency.
- ANSI/IICRC S520: Standard for Professional Mold Remediation. Institute of Inspection, Cleaning and Restoration Certification.