Basement mold remediation

Basement Mold Remediation in Philadelphia

Musty smell, white or black growth on the walls, spots on the bottom of the drywall. Onyx removes basement mold and fixes the moisture that caused it, so it does not come back.

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Philadelphia basements are below grade, often have old stone or block foundations, and carry water heaters, washers and the main line. That is a lot of moisture in a space with little air movement, which is why most of the mold we remove is in basements.

Bleach and paint do not fix it. The mold is in the drywall paper, the carpet pad and the framing, and it comes back as long as the moisture does.

Where basement mold grows

  • The bottom of finished drywall, especially behind furniture and in corners
  • Carpet and pad on a slab
  • Basement ceiling joists and subfloor above a damp space
  • Stored cardboard boxes, wood and fabric
  • Foundation walls with efflorescence (white mineral deposits) and damp spots

What causes it

  • Past flooding or a sewage backup that was not fully dried
  • Groundwater through the foundation after heavy rain
  • Plumbing leaks from the water heater, washer or supply lines
  • Condensation on cold walls and pipes in summer humidity
  • No dehumidification in a finished basement

How Onyx removes basement mold

  • Inspection and moisture mapping to find every affected area and the source
  • Containment under negative air so spores do not reach the rest of the house
  • Removal of moldy drywall, insulation, carpet and pad
  • HEPA vacuuming and antimicrobial treatment of framing and masonry
  • Drying and dehumidification to dry standard
  • Fixing or referring the moisture source before closing up
  • Rebuild of walls and flooring

Certified mold remediation →

Crawl space mold

Crawl spaces under additions and older homes trap moisture against the subfloor. The same process applies: find the moisture, contain, remove, treat and dry, then control humidity so it stays dry.

How it goes

What happens after you call.

  1. Inspect

    Find the mold, measure the moisture and identify the source.

  2. Contain

    Barriers and negative air keep spores in the basement.

  3. Remove and treat

    Moldy materials come out; framing and masonry are cleaned and treated.

  4. Dry and fix the cause

    Dry standard, then the moisture source is fixed or referred.

  5. Rebuild

    Walls and floors go back in.

Google reviews

What customers say

5.0 from 7 Google reviews · Verified

★★★★★

Used Onyx to clean out mother in laws house after she passed. This was by [no] means a simple clear out. They did an absolutely amazing job! Job was finished when promised. I can’t say enough good things about the owner Jose and his team. Would definitely recommend this company.

Howard · House clean-out

★★★★★

Great experience with this mitigation company! Professional, reliable, and got the job done quickly. The team was friendly, respectful, and kept everything handled from start to finish. Highly recommend!

Angel C. · Water mitigation

★★★★★

Overall, great experience with Onyx. I’ve used Jose as a lead on multiple multi-housing projects and have always found his pricing to be competitive. He gets the job done, is honest and trustworthy and knows how to lead a team. 10/10!

Ashley E. · Multi-housing projects

Read all reviews on Google

FAQ

Questions we get on this work

What should I do about mold in my basement?

Find and stop the moisture first, then remove the mold and the porous material it grows in. For more than about 10 square feet, or mold inside walls, call a professional. Onyx gives free estimates.

Is basement mold dangerous?

It can trigger allergies and breathing problems, especially for children, older adults and anyone with asthma. The spores travel upstairs through air returns and stairwells.

How much does basement mold removal cost?

It depends on the area affected, what has to be removed and whether the moisture source needs repair. We give a free written estimate after inspecting.

Will a dehumidifier get rid of basement mold?

No. A dehumidifier helps prevent new growth by keeping humidity down, but existing mold has to be removed.

Next step

Mold in the basement? Call Onyx.

We remove it and fix the moisture so it stays gone.

Call (267) 353-7953

Not an emergency? Request a callback online and Onyx will call to confirm a time.

Call Onyx · 267-353-7953