Found mold? Start here
In short: if you see or smell mold in a Bothell, WA home, stop the water source first, avoid disturbing the mold, and measure the area. Under about 10 square feet you can often clean it yourself. Larger areas, sewage water and hidden mold call for a professional.
Mold remediation always has two parts: remove the mold, and fix the water problem that fed it. The US EPA says that if you clean the mold but leave the moisture, the mold will most likely come back.
- Stop the water. Fix the leak, close the valve or dry the wet area. Nothing else works until the moisture stops.
- Leave it undisturbed. Washington's Department of Health notes that mold releases spores into the air when it is disturbed, so avoid stirring it up.
- Measure the patch. About 10 square feet is roughly a 3 foot by 3 foot area. That line decides who should do the work.
- Protect yourself. Gloves, goggles and an N-95 respirator, and keep children, pets and anyone with asthma away.
- Decide. Small and dry-cleanable: follow the cleaning steps below. Large, hidden or sewage-related: call a company that works on mold.
Sources: US EPA: A Brief Guide to Mold, Moisture and Your Home; Washington State Department of Health: Mold.
Why mold shows up after water damage
Mold spores are always in the air, but they only start growing when they land on something wet. After a leak, a burst pipe or a flood, wet drywall, carpet, ceiling tiles and insulation become the food and water mold needs.
Washington's Department of Health says mold grows on almost any surface, including wood, wallpaper, paint, carpet, sheetrock and insulation, and thrives where there is plenty of moisture, such as from a leaky roof, high humidity or a flood. Basements, bathrooms, kitchens, laundry rooms and cold exterior walls are common trouble spots.
The US EPA recommends drying water-damaged areas and items within 24 to 48 hours, and keeping indoor relative humidity below 60 percent, ideally between 30 and 50 percent. A moisture or humidity meter from a hardware store shows where you stand. If the water came from a leak or burst pipe, see water damage restoration in Bothell. If it came from outside, see flood cleanup in Bothell.
Sources: Washington State Department of Health: Mold; US EPA: A Brief Guide to Mold, Moisture and Your Home.
How big is the mold? The 10 square foot line
Size decides who does the work. Both the US EPA and Washington's Department of Health use about 10 square feet, a patch roughly 3 feet by 3 feet, as the dividing line.
| Situation | What the guidance says |
|---|---|
| Less than about 10 square feet | In most cases you can handle it yourself by following the cleaning guidelines |
| More than about 10 square feet, or a lot of water damage | Consider hiring a cleaning professional |
| Sewage or other contaminated water | Call a professional with experience cleaning buildings damaged by contaminated water |
| Hidden mold behind walls, wallpaper or ceilings | Hire an experienced professional, because investigating can release spores |
| Mold near or inside the HVAC system | Do not run the system, since it could spread mold through the building |
| Health concerns in the household | Talk to a health professional before you start cleanup |
If sewage is involved, start with sewage cleanup in Bothell, because contaminated water adds hazards that mold cleanup alone does not cover.
Sources: US EPA: A Brief Guide to Mold, Moisture and Your Home; Washington State Department of Health: Mold.
Do you need a mold test?
Usually not. If you can see or smell mold, you already know you have it, and the next step is fixing the moisture and removing the growth.
The US EPA says sampling is unnecessary in most cases when visible mold is present, and that no federal limits exist for mold in a building. Surface sampling can help show whether an area was cleaned well, but it should be done by someone with experience in sampling methods and in reading the results. Washington's Department of Health says even a clean, dry house has some mold spores, just not enough to cause health problems.
Sources: US EPA: A Brief Guide to Mold, Moisture and Your Home; Washington State Department of Health: Mold.
Cleaning a small area safely
For a patch under about 10 square feet on hard surfaces, the steps are protect, seal, remove, scrub, dry and monitor. This is general guidance from public agencies, and professionals may use methods it does not cover.
- Protect yourself. Wear gloves, goggles without ventilation holes and an N-95 respirator that fits properly. Avoid touching mold with bare hands.
- Seal the area. Close it off from the rest of the home, cover heat registers and vent grills, and open a window before you start.
- Move items out. Take furnishings to a mold-free area, and clean them separately.
- Bag moldy materials. Tie off the bags and carry them outside to the garbage container right away.
- Scrub and dry. Wash hard surfaces with detergent and warm water, then dry them completely.
- Finish with a borate-based detergent. Washington's Department of Health suggests applying it without rinsing to help keep mold from returning.
- Clean the room and watch it. Vacuum, wash exposed bedding and clothing, and check the area regularly for regrowth.
Sources: Washington State Department of Health: Mold; US EPA: A Brief Guide to Mold, Moisture and Your Home.
What can be cleaned and what usually goes
Hard, non-porous surfaces usually clean up. Porous materials that stayed wet are harder, because mold grows into the empty spaces and crevices and may be impossible to remove completely.
| Material | What usually happens |
|---|---|
| Metal, glass, plastic, ceramics | Wipe with lukewarm water and detergent |
| Washable clothes and bedding | Wash in the laundry |
| Ceiling tiles and carpet | May have to be thrown away if they become moldy |
| Wet drywall and insulation | Often removed and replaced, since they hold moisture |
| Sofas and beds that cannot be washed | May need to be discarded; some can be vacuumed and aired out, then watched for regrowth |
Mold can also stain and damage surfaces, so an item may not look the same even after it is clean. For valuable or sentimental pieces, the US EPA suggests asking a specialist and checking references.
Sources: US EPA: A Brief Guide to Mold, Moisture and Your Home; Washington State Department of Health: Mold; US EPA: Mold remediation guide, Chapter 4.
Bleach, paint and sprays: what to skip
- Do not paint or caulk over mold. Paint on a moldy surface is likely to peel, and the mold keeps growing underneath.
- Do not rely on bleach. The US EPA does not recommend chlorine bleach or other biocides as a routine part of mold cleanup. Dead mold can still cause allergic reactions, so it must be removed, not just killed.
- Never mix bleach with ammonia. Toxic fumes can form. If you use any disinfectant, ventilate the area and exhaust the air outdoors.
- Do not try to sterilize the room. A background level of spores always remains, and it will not grow once the moisture problem is solved.
Sources: US EPA: A Brief Guide to Mold, Moisture and Your Home; Washington State Department of Health: Mold.
Hidden mold, wallpaper and the HVAC system
A musty smell with nothing visible often means mold is hiding. The US EPA lists the back of drywall, wallpaper and paneling, the top of ceiling tiles, the underside of carpet and pads, inside walls around leaking pipes and behind furniture as common spots.
Take care with wallpaper in particular: removing it can release a large amount of spores if mold is growing on the underside. If you know or suspect the HVAC system is contaminated, the EPA says not to run it, and points to its air duct guide first. Investigating hidden mold means disturbing it, so the EPA suggests hiring an experienced professional.
Source: US EPA: A Brief Guide to Mold, Moisture and Your Home.
What professional mold remediation involves
The steps are the same whichever company you call: find and fix the moisture, contain the area, remove the mold and the materials that cannot be saved, clean and dry what remains, and check the result.
- Find the moisture source. A leak, a flood, condensation or high humidity has to be identified and fixed first.
- Contain the area. Sealing it off helps stop spores moving to clean rooms.
- Remove what cannot be saved. Moldy porous materials such as ceiling tiles, carpet and wet insulation are usually bagged and thrown away.
- Clean hard surfaces and dry everything. Surfaces are cleaned and the structure is dried completely.
- Check the result. The work should be revisited shortly afterward to confirm there is no new moisture or mold.
Sources: US EPA: A Brief Guide to Mold, Moisture and Your Home; US EPA: Mold remediation guide, Chapter 4; Washington State Department of Health: Mold.
How you know the cleanup is finished
The US EPA says the job is not finished until the water problem is completely fixed, and calls the final judgment a judgment call.
- The water or moisture problem is completely fixed.
- Visible mold and moldy odors are gone. Staining may remain.
- A visit shortly after cleanup shows no new water damage or mold growth.
- People can use the space again without health complaints or symptoms.
Source: US EPA: A Brief Guide to Mold, Moisture and Your Home.
Does insurance cover mold in Washington?
Usually not on its own. Washington's Office of the Insurance Commissioner says mold, rot, fungi and rust are typically excluded unless they result from water damage your policy covers, and some insurers offer limited mold coverage as an add-on.
That is one more reason to document the water damage and report it quickly. Our guide to water damage insurance in Washington explains the sudden versus gradual line, and you can choose your own contractor.
Source: WA Office of the Insurance Commissioner: Leaks, water damage and mold.
Hiring a mold cleanup company: what to ask
- Does the company have experience cleaning up mold, and can it give references?
- Will it follow EPA or ACGIH guidelines for the work, as the US EPA suggests asking?
- How will it find and deal with the water source, so the mold does not return?
- Is the scope of work in writing, including what will be removed and what will be dried?
- Is the company registered? Look it up on the Washington L&I Verify tool before you sign.
- Will someone revisit the area after the work to confirm it stayed dry?
Read any assignment of benefits form carefully before signing it, because it can hand control of your claim payments to the contractor.
Sources: US EPA: A Brief Guide to Mold, Moisture and Your Home; WA Labor & Industries: Verify a contractor; WA Office of the Insurance Commissioner: Filing a homeowner insurance claim.
Local help in King and Snohomish County
Bothell sits in two counties, so your county health department depends on which side your address is on. Washington's Department of Health points residents to their county health department and runs a Mold and Indoor Air Quality information line at 360-236-3090.
Public Health, Seattle and King County says it does not regulate indoor air quality and does not routinely conduct home assessments for indoor air quality problems, but its website has guidance on preventing and cleaning up mold and resources for tenants. After a flood, King County also advises wearing an N95 mask, gloves and goggles when you return to your home, and notes that mold can grow within 24 to 48 hours. Basements and crawlspaces are covered in our flood cleanup guide, and the Bothell flood risk guide shows where water has reached homes.
Sources: Washington State Department of Health: Mold; Public Health, Seattle & King County: Indoor air quality and mold; Public Health, Seattle & King County: Flood recovery resources.
Mold questions
Is it safe to live in a house with mold?
It depends on the person and on how much mold there is. Washington's Department of Health says most molds do not harm healthy people, but people with allergies or asthma may be more sensitive, and people with a weakened immune system or lung disease are at higher risk of infection. If anyone at home has health problems you think are linked to mold, talk to a doctor, and do not wait on the cleanup.
Does painting over mold stop it?
No. Both the US EPA and Washington's Department of Health say not to paint or caulk over mold. The mold keeps growing under the paint and the paint peels. Clean the mold off, dry the surface completely, then paint.
Can mold ever be removed completely?
Not entirely. The US EPA says it is impossible to get rid of all mold and mold spores indoors, because some spores float through the air and settle in house dust. What you can do is remove the mold that is growing and fix the moisture, because spores will not grow without it.
How fast does mold grow after water damage?
The US EPA says that if wet or damp materials are dried within 24 to 48 hours after a leak or spill, mold will not grow in most cases. After that window the risk rises, which is why drying quickly matters as much as cleaning.
Do I need a mold test?
Usually not. Washington's Department of Health says you do not need to sample for mold because in most cases you can see or smell it. The US EPA adds that no federal limits exist for mold or mold spores, so a sample cannot show compliance with a standard. Surface sampling by an experienced professional can help check whether an area was cleaned properly.
Does bleach kill mold?
Bleach can kill mold, but the US EPA does not recommend it as a routine step in mold cleanup, and dead mold can still cause allergic reactions, so it has to be removed anyway. Washington's Department of Health lists a diluted bleach wipe as an optional step. Never mix bleach with cleaners that contain ammonia, because toxic fumes can form.
Does homeowners insurance in Washington cover mold?
Usually not. Washington's Office of the Insurance Commissioner says mold is typically excluded unless it comes from water damage your policy covers, and some insurers offer limited mold coverage as an add-on. Check your policy or ask your agent before you file.
How do I choose a mold cleanup company?
The US EPA suggests hiring a contractor with experience cleaning up mold, checking references, and asking the company to follow EPA or ACGIH guidelines. Look the company up on the Washington L&I Verify tool, and remember you can choose your own contractor even if your insurer suggests one.
I rent. Who has to fix the mold?
Washington's Department of Health says tenants and landlords both have responsibilities. Generally the landlord fixes leaks, and the renter reduces condensation. Report plumbing leaks and moisture problems to your landlord in writing, and keep a copy.