Mold in the Basement: Causes, Removal and Prevention

Basements are the most common place for mold in a house. They're cooler, often more humid and closer to the soil, and they're where water ends up after almost any leak or flood. In many Littleton homes, the basement is also finished, which means the drywall, carpet and framing mold loves are right there. If the growth is large or keeps coming back, Reestorian can connect you with a local provider for mold removal and remediation in Littleton.

This is general information, not medical advice. If you're worried about symptoms, talk with a doctor.

Why basements grow mold

How to identify mold in your basement

• A musty, earthy smell, often strongest in storage rooms and closets
• Spots or fuzzy growth in black, green, white or gray on drywall, wood, paneling or boxes
• Staining at the base of finished walls or behind baseboards
• Peeling paint or warped paneling
• Allergy-like symptoms that seem worse in the basement

Not everything that looks like mold is mold. White, powdery deposits on concrete may be efflorescence, minerals left behind as water moves through the wall. It isn't mold, but it means moisture is getting in.

Is the mold in my basement dangerous?

The CDC says mold can cause a stuffy nose, sore throat, coughing or wheezing, burning eyes or a skin rash in some people. People with asthma or mold allergies may react severely, and people with weakened immune systems or chronic lung disease may develop lung infections.

The CDC also says all molds should be treated the same way for health risks and removal, so you don't need to know whether it's "black mold." If it's growing indoors, remove it and fix the moisture.

How to get rid of mold in the basement

• Find and stop the moisture. No cleanup lasts if water keeps coming. Fix leaks, seepage or humidity first.
• Protect yourself. The EPA recommends at least an N95 respirator, goggles that seal around the eyes and nitrile, vinyl or rubber gloves.
• Keep sensitive people out. The EPA says people with asthma or weakened immune systems should stay away, and children shouldn't help.
• Remove moldy porous materials. Moldy drywall, insulation, carpet and pad and cardboard boxes usually can't be cleaned well and should be bagged and removed.
• Clean hard surfaces. Scrub concrete, metal and sealed wood with detergent and water, then dry completely.
• Dry the space. Run a dehumidifier and fans until surfaces are dry, and check with a moisture meter.
• Don't run the HVAC if you think it's contaminated with mold, as the EPA warns it can spread spores.

If you use bleach on hard surfaces, the CDC warns never to use it in a closed space and never to mix it with ammonia.

DIY or professional mold removal?

How to get rid of basement mold in walls

Mold in a finished wall usually means the drywall and insulation behind it got wet. Cleaning the surface won't reach growth on the back of the drywall or on the framing. A remediation provider sets up containment, cuts out the affected drywall and insulation, HEPA vacuums and cleans the studs, dries the cavity and confirms it's dry before new drywall goes up.

How to get rid of mold smell in the basement

A musty smell is the most common first sign of basement mold. Getting rid of it means removing what causes it, not covering it up:

1. Find the source. Check storage boxes, the base of finished walls, under stairs, around the water heater and near the sump pit.
2. Fix the moisture. Repair leaks, clear window wells and improve drainage.
3. Remove moldy porous items. Cardboard, old carpet, padding and moldy drywall hold the odor.
4. Clean hard surfaces with detergent and water and dry them.
5. Run a dehumidifier to keep humidity below 60 percent, ideally 30 to 50 percent.
6. Increase air movement with fans, and keep vents and returns clear.

If the smell returns within a few weeks, there's likely moisture or growth you haven't found, often inside a wall or under flooring.

How to prevent mold in the basement

• Keep humidity below 60 percent, ideally 30 to 50 percent, as the EPA recommends. A hygrometer and dehumidifier help.
• Dry any water within 24 to 48 hours.
• Test the sump pump each spring and fall. NDSU Extension suggests pouring water into the pit to make sure it starts and stops.
• Extend downspouts and grade soil away from the foundation.
• Insulate cold water pipes to stop condensation.
• Store items in plastic bins, not cardboard, and keep them off the floor and away from exterior walls.
• Vent the dryer outdoors and keep the vent clean.
• Prevent sewer backups by keeping grease and wipes out of drains, as the City of Littleton advises.

Basements in Littleton and the south metro

Finished basements are common across Littleton, Centennial and Highlands Ranch. They're comfortable living space, but they hide water. A slow leak behind a wall or a sump pump that overflowed once can feed mold for months without anyone noticing. Colorado's dry outdoor air helps, but basements still run cooler and more humid than the rest of the house, especially in summer. Treat any basement water event as a mold risk and dry it with measured readings, not by feel.

Related reading: Learn how long it takes mold to grow after a leak, and how to spot sump pump failure before it floods the basement.

When should you call a mold remediation professional?

Call a professional when:

• Mold covers more than about 10 square feet
• It's inside finished walls, under carpet or in ductwork
• It followed a sewer backup or flood
• It keeps coming back after cleaning
• Someone in the home has asthma, allergies or a weakened immune system

Basement mold in Littleton? Call (928) 394-5135 to reach a local mold remediation provider.