Hello and thank you in advance for your input. We had a significant leak of our washer in a room above finished basement. We opened up the wettest ceiling and wall drywall downstairs and utilized dehumidifiers and fans to dry out. Upstairs where the leak was we’re having a harder time drying out the subfloor. We pulled up the tile to dry out the floor. The subfloor had a small space about 15” x 4” up next to the back wall that was still registering higher with moisture meter so we stepped up our game with rented fans and dehumidifier. We’re still getting just a couple spots reading high even after a 2 days of home fans and dehumidifier and an additional day with professional fan and dehumidifier. Ideas? Poor readings with something interfering possibly?
Further, the leak had water trickling under the corner of the laundry closet and possibly seeping into tiled bathroom floor next door. I used a moisture meter to monitor. Most areas of the tiles show 6-12% but there is one bit of area that reads 20-30%. I’m assuming this means the water seeped under there since the rest of the tiles are lower. We pulled up one row of tiles to find the crumbly cement backer board underneath and I can’t see the subfloor yet. I know moisture meters aren’t perfectly reliable with tile, but since most of the bathroom is 12% or less am I correct to assume the strip of tiles with higher reading is likely a bit wet? It’s near the front of the room where there is a door way and transition to wood floor. It doesn’t appear to have metal.
I am highly sensitive to mold so I want to be cautious but also don’t want to pull out more tile for a poor meter reading.
Morning, Maude. Hope to find you well and in good spirits today.
Less expensive moisture meters may only offer accuracy within 5-20% range. High-quality professional moisture meters on the other hand provide much greater precision. Some as high as within 0.1%. Importantly, you have to understand how to effectively operate the moisture meter.
I hope I am expressing myself properly to help you understand moisture readings and drying times of wood subflooring evaporation and curculation. Environmental conditions; Humidity and Temperature, Air circulation, or lack thereof… Evaporation and circulation are key factors.
Consider not only the drying times of subfloor sheathing, but also the structural components the subflooring is secured to. Wet/Saturated Floor joists or Wet/Saturated floor truss upper-chords will likely impede the strip of subfloor sheathing it is secured to.
When everything is dry. Antimicrobial/no-mold spray products on exposed wood and let it dry before covering it up. Mold Armor to remediate any suspect mold and prevent molds recurrence.
Then you need to get Servpro in and professionally address the leak remediation. If your concerns are related to Stachybotrys, i.e. “black mold” they can and will test for that as well.
Short of that, you need to open all walls that were affected, use tools that lower the humidity significantly below ambient and treat any exposed surfaces with antifungal and antimicrobial treatments.
If mold has already appeared, it may need to be physically removed first. This is not a DIY project. It requires tools and PPE that ensure it doesn’t get spread further while you’re removing it.
Just give it more time to dry. Mold needs a source of water (and the right temperature) to grow and produce the spores to which you are sensitive. No water = no growth = no spores. If the room is cold, you might try a space heater for awhile, in addition to the fans. Warm air will absorb water faster.
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ndegaris
(Neil DeGaris, CMI KY License # 102167)
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Can you be sure that the following items are not impacting your readings?
The presence of metal in the wall or floor can significantly impact moisture meter readings due to its conductive properties and ability to distort electric fields. Metal objects such as nails, screws, electrical wiring, or metal pipes can create false moisture readings or interfere with accurate measurement results.
Great points. Also, dew point which effects surface moisture on the tile. The OP acknowledged tile is a problem when detecting moisture. Kudos there. I don’t think the answer will come cheap.
