How to Remove Mold From Plywood Subfloor
The smell of mildew hitting you when you kick open the basement door is one of the most expensive smells in construction. I was on a framing job last November where the crew didn’t even bother checking moisture levels on the OSB sheathing until we started nailing up the first joist hangers and found black spots blooming across the surface. They thought it was just dirt from the truck. It wasn’t dirt; it was active mold growth caused by a roof leak that had been ignored for three weeks. We didn’t have to cut a single board because they caught it early enough to dry it out, but if we hadn’t? The whole subfloor assembly would have rotted through to the joists. That cost us ten thousand bucks in materials alone, plus two days of downtime waiting for delivery on replacement lumber.
You don’t need expensive industrial equipment for a standard remediation job, but you do need the right gear to keep yourself safe and the site contained.
- P100 Respirator: Protects lungs from spores better than an N95 in high-load environments.
- Industrial Wet/Dry Vacuum: Essential for removing standing water and sludge from joist bays.
- Oxygen Bleach Cleaner: Safer alternative to chlorine bleach for porous wood surfaces.
- Stiff Wire Brush: Needed to penetrate the grain of the plywood fibers.
- Moisture Meter: Verify dryness before closing up the job. A reading below 12% moisture content is generally safe for interior flooring once cured.
