Mold After Firefighting Water in Coachella, CA

The fire is out, but the water is still in the walls — and where there is water, there is mould. A wall that is closed while it is still wet will grow mould, and the mould will spread through the framing and the insulation, and the wall will have to be opened again and the job done twice. This post explains why mould grows after firefighting water, how fast it spreads, and why the walls stay open until the readings say the moisture is normal.

The second thing to understand is that the mould is not a separate problem. It is the water, and the water is the firefighting, and the drying is what stops it. The provider maps the water on the first visit, runs the air movers and dehumidifiers, and reads the moisture every day until it is normal — because the readings are what say when the job is done, and the readings are what keep the job honest.

Why Mould Grows After Firefighting Water

Mould grows where there is water, and the firefighting left water in the floors, the ceilings, the insulation, and the wall cavities. The water soaks deeper into floors and wall cavities with every hour it sits, and the mould follows it. A room that looks dry on the surface can still be wet inside the wall, and a wall that is closed too early will grow mould and have to be opened again.

Mould grows fast. In the Coachella Valley's heat, a wet wall can start growing mould in a day or two, and the mould spreads through the framing and the insulation while the wall is still closed. The provider reads the moisture every day, and the walls are closed only when the readings say the moisture is normal — not when the surface feels dry, and not when the calendar says it is time.

Mould grows where the air cannot reach. A wall cavity is dark, warm and wet after a fire, and the mould grows in it without being seen. The provider maps the water on the first visit, and the drying follows the map, not the eye, because a floor that looks dry can still be wet underneath. The moisture is read with a meter, not with a hand, because the hand can only feel the surface.

How Fast It Spreads

Mould spreads fast, and it spreads through the framing, the insulation, and the air. A wall that is closed while it is still wet will grow mould, and the mould will spread to the rooms beside it and the rooms above it, and the smell will come back through the vents when the air conditioning is turned on. The provider seals the vents before cleaning, and the drying follows the map.

Mould spreads through the air, and the air carries it to every room in the house. Turn the air conditioning on before the drying is done, and the mould spreads to rooms that were not affected. The vents should stay sealed until the drying is done, and the air conditioning should stay off until the provider says otherwise. The provider seals the room, runs the air scrubber, and works in protective equipment.

Mould spreads through the materials, and the materials hold it. The insulation behind the walls, the framing, the subfloor — each absorbs water, and each grows mould if it is not dried. The provider removes the insulation that cannot be dried, and the framing is dried and checked before the walls are closed. The provider will tell you what was removed, and what was dried, before any work starts.

Why the Walls Stay Open

The walls stay open because the moisture is inside them, not on them. A wall that looks dry on the surface can still be wet inside, and a wall that is closed too early will grow mould and have to be opened again. The moisture is read with a meter, in the material, not on the surface, because the surface dries first and the inside dries last.

The walls stay open because the readings decide, not the calendar. The moisture is read every day, and the walls are closed only when the readings say the moisture is normal — not when the surface feels dry, and not when the calendar says it is time. The readings decide, and the readings are what keep the job honest. The provider will show you the readings, because the readings are the record.

The walls stay open because the mould follows the moisture. A wall that is closed while it is still wet will grow mould, and the mould will spread, and the wall will have to be opened again and the job done twice. The readings are what stop that from happening, and the readings are what say when the job is done. The provider will not close a wall before the readings are normal.

What the Provider Does About Mould

The provider maps the water on the first visit, and the drying follows the map. The air movers and dehumidifiers run through the job, and the moisture is read every day until it is normal. The insulation that cannot be dried is removed, and the framing is dried and checked before the walls are closed. The provider will tell you what was removed, and what was dried, before any work starts.

The provider removes the mould where it has grown, and the removal is done with the room sealed and the air scrubber running, so the mould does not spread to rooms that were not affected. The provider works in protective equipment, because the mould is irritating to the lungs, the eyes and the skin, and the room should stay closed until the removal is done.

The provider treats the surfaces after the removal, so the mould cannot come back. The treatment is applied after the cleaning, not before it, and the room is checked against the reference again. The provider will tell you what the treatment found, and what still needs to be done, before the next step starts. The smell is the last thing to go, and it is the thing that tells you whether the job is done.

What Not to Do

Do not close the walls before the readings are normal. A wall that is closed while it is still wet will grow mould, and the mould will spread, and the wall will have to be opened again and the job done twice. The provider will not close a wall before the readings are normal, and the provider will not start the rebuild before the cleaning is done.

Do not turn on the air conditioning before the drying is done, because it pushes the soot and the mould through the ducts and spreads them to rooms that were not affected. The vents should stay sealed until the drying is done, and the air conditioning should stay off until the provider says otherwise. Do not mop the water and call the job done, because a mop cleans the surface, but the water underneath stays.

Do not clean the mould yourself with a household cleaner, because the cleaner does not remove it and it spreads the spores into the air. Do not throw anything away without photographing it first, and do not start cleaning before the adjuster has seen the damage, unless the provider tells you the cleaning cannot wait. The cleaning starts when the provider arrives, and it starts with an assessment, not with a mop.

Mold After Firefighting Water, in Order

1. Map the water — The provider maps the water on the first visit — the floors, the ceilings, the insulation, the wall cavities.
2. Run the machines — Air movers and dehumidifiers run for days, day and night, and the readings are taken every day.
3. Remove what cannot be dried — The insulation that cannot be dried is removed, and the framing is dried and checked.
4. Check the readings — The walls are closed only when the readings say the moisture is normal.
5. Treat the surfaces — The surfaces are treated after the removal, so the mould cannot come back.

Mistakes That Let Mold Grow

• Closing walls before the drying readings are normal
• Turning on the air conditioning before the drying is done
• Mopping the surface and calling the job done
• Cleaning mould with a household cleaner, which spreads the spores
• Waiting while the water soaks deeper into floors and wall cavities

For help with this in Coachella, see Firefighting Water Extraction & Drying in Coachella — or go back to the Coachella fire damage restoration home page.