The short answer
Common Sources of the Smell
The most obvious source is stored mothballs, often left in closets, attics, or storage boxes. The chemicals they release can soak into nearby fabrics, wood, and drywall, leaving a strong odor that lasts for months. Even after you remove the mothballs, the smell can persist in porous materials.
If you don't recall using mothballs, the smell might come from a different chemical source. Some cleaning products, pesticides, or even certain plastics can emit a similar odor. Check for any old containers or forgotten items that might have been stored with mothballs.
- Inspect closets, drawers, and storage bins for loose mothballs
- Check under beds and in attic spaces for forgotten items
- Look for old clothing or blankets that may have been treated with moth repellent
- Smell test different rooms to narrow down the source
What to Do First
Start by locating the source of the smell. Open windows and doors to ventilate the space, and remove any obvious mothballs or treated items. Wash or dry-clean affected fabrics, and vacuum carpets and upholstery thoroughly. Activated charcoal or baking soda can help absorb odors temporarily.
If the smell persists, you may need to investigate for moisture. Check under sinks, around toilets, and near water heaters for leaks. Feel walls for dampness and look for peeling paint or bubbling wallpaper. If you find any signs of water, you may need professional help to dry the area and prevent mold growth.
When to Call the Pros
If you suspect a hidden water leak or mold growth, it's wise to call local water damage pros. They have the tools to detect moisture behind walls and under floors without tearing things apart. They can also dry out affected areas and help prevent mold from spreading.
In coastal areas with wet winters and dry summers, moisture issues can be more common. Pay attention to any musty smells after heavy rain, as this could signal a hidden leak. Early detection can save you from more extensive damage and health concerns.
- Use a moisture meter to check walls and floors for dampness
- Look for mold growth on baseboards, window frames, or under sinks
- Listen for dripping sounds or the sound of running water when everything is off
- Consider a professional water damage inspection if you can't find the source
Preventing Future Odors
Once you've addressed the source, take steps to keep your home dry and well-ventilated. Use exhaust fans in bathrooms and kitchens, and fix any plumbing leaks quickly. Keep humidity levels in your home between 30 and 50 percent to discourage mold growth.
If you use mothballs, store them in airtight containers and keep them away from living areas. Consider using cedar chips or lavender sachets as alternatives that don't leave harsh chemical smells. Regular cleaning and airing out your home can help keep odors from lingering.
Need help right now?
Call (425) 407-5186 any time, day or night, and describe what happened.
Call Now (425) 407-5186Frequently asked questions
Can a water leak really cause a mothball smell?
Yes. Water leaks create damp conditions where mold and mildew can grow, and some types of mold produce a strong, musty odor that people often describe as mothball-like. The smell can also come from chemicals in building materials that react with moisture.
How long does a mothball smell last?
It depends on the source and how much material was affected. If mothballs are the cause, the smell can linger for weeks or months, especially in porous surfaces like carpet and drywall. If it's from mold, the odor will persist until the moisture problem is resolved and the mold is removed.
Is a mothball smell dangerous?
Mothball fumes can be harmful if inhaled in large amounts, especially in poorly ventilated areas. Mold can also trigger allergies or respiratory issues. If you feel unwell, see a doctor. For safety, ventilate the area and avoid prolonged exposure while you track down the source.