IICRC-certified mold remediation specialist
Certified Mold Remediation, Removal and Inspection in Philadelphia
Black spots on drywall, a musty basement, a closet that never dries. Onyx finds the moisture feeding the mold, contains the area, removes the growth and the material it lives in, and fixes the cause so it stays gone.
- IICRC certified
- 24/7 emergency response
- Insured
- 17 years in restoration
- Free estimates
- Works with your insurance
Mold is a moisture problem with a biology symptom. Every mold job in Philadelphia traces back to water: a slow leak behind a wall, a damp rowhome basement, a bathroom without an exhaust fan, a roof that has been dripping into insulation for a season. Spraying bleach on the spots does not touch the source and usually spreads spores.
Onyx does remediation the way it is supposed to be done: find and stop the moisture, contain the area under negative air, remove the mold and the porous materials it colonized, clean and treat what stays, dry the space, and only then rebuild.
Professional mold inspection: what we look for
Before anyone touches a wall, we need to know how far it goes and what is feeding it: moisture readings, thermal imaging, and a written scope with photos.
Certified mold removal and remediation
Remediation removes the growth and the conditions that caused it. This is the sequence.
- Containment: plastic barriers and negative air machines so spores do not travel through the house
- PPE for the crew: full suits and respirators, every time
- Removal of colonized porous materials: drywall, insulation, carpet, ceiling tile
- HEPA vacuuming and antimicrobial treatment of framing and hard surfaces that stay
- Bagging and disposal of contaminated material
- Drying of the cavity and fixing the moisture source before closing up
- Rebuild of removed drywall, trim, flooring and paint
Mold testing
Testing has a place: when you cannot see growth but have symptoms or a smell, when a landlord or buyer needs a lab result, or when a clearance test is required after remediation. It is not always needed when growth is visible; if you can see mold, the answer is to remove it and fix the water.
Be careful with offers of free mold testing from a company that also sells remediation. Ask what the test measures and who reads it. Onyx will tell you when testing is worth paying for and when it is not. Ask us about independent testing options when you call.
Mold in Philadelphia homes
Older rowhomes with damp below-grade basements, brick that has lost its pointing, flat roofs with standing water, and bathrooms that vent into the attic are the usual suspects. Summer humidity makes a wet basement a mold basement. We see it in South Philly, Kensington, Germantown and the suburbs alike.
Black mold, basement mold and crawl space mold
Most of the mold we remove in Philadelphia is in basements and crawl spaces, where moisture comes through foundation walls or from plumbing leaks. Black mold removal follows the same containment and removal process as any other mold; the color does not change the method, the size and the moisture source do.
- Mold in basement walls and ceilings
- Crawl space mold remediation
- Black mold removal
- Mold behind bathroom and kitchen walls
Attic mold and bathroom mold
Attic mold usually comes from a roof leak, bathroom fans venting into the attic, or poor ventilation that lets winter condensation collect on the roof sheathing. Bathroom mold spreads from caulk and grout into the drywall behind the tub or shower when there is no exhaust fan or a slow leak in the wall.
Both follow the same process: find the moisture, contain, remove the colonized material, treat what stays, and fix the ventilation or leak before closing up.
What you may be seeing
- Black, green or white fuzzy spots on drywall, grout or wood
- A musty smell in the basement, a closet or under a sink
- Bubbling paint or soft drywall near a bathroom or window
- Allergy-type symptoms that get worse at home
- Past water damage that was dried with fans only
How it goes
What happens after you call.
Call and describe what you see
Where the growth is, how big, how long, and whether anyone in the home has symptoms. We tell you what to avoid touching.
Inspect and find the moisture
Meters, thermal imaging and a look behind surfaces. The scope is written and photographed.
Contain
Barriers and negative air isolate the work area from the rest of the house.
Remove and treat
Colonized material comes out bagged. What stays is HEPA vacuumed and treated.
Fix the water and dry
The leak, drainage or ventilation problem is corrected and the cavity dried before it is closed.
Rebuild
Onyx replaces drywall, trim and flooring so the area matches the rest of the room.
Proof
On the job
Onyx crews in full PPE on mold jobs: containment, material removal and HEPA cleanup.
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.
★★★★★
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!
★★★★★
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!
FAQ
Questions we get on this work
How much does mold remediation cost in Philadelphia?
It depends on the size of the affected area, whether it is in an open basement or inside finished walls, how much material has to come out, and what has to be fixed to stop the moisture. Small contained areas are modest jobs; whole-basement or attic remediation with rebuild is a larger project. Onyx gives free written estimates after inspection. See our mold remediation cost guide for the factors.
Do I need a mold inspection before remediation?
You need to know the extent and the moisture source before remediation, which is what an inspection is. Onyx does the inspection as the first step of the job. A separate paid inspection makes sense if you want an independent opinion or a lab result for a landlord, buyer or insurer.
Is free mold testing legit?
Sometimes, but ask questions. A free test that always finds mold and always leads to a big remediation quote is a sales tool. Every home has some mold spores. What matters is visible growth, elevated moisture and a source. Onyx will tell you whether testing is worth it in your case.
Does insurance cover mold remediation?
Usually only when the mold results from a covered sudden loss, like a burst pipe, and often with a cap. Mold from long-term leaks, humidity or neglected maintenance is commonly excluded. We document the source and timeline so your adjuster has the full picture.
What is the difference between mold removal and mold remediation?
Searchers use them interchangeably. Removal is taking out the growth. Remediation is removal plus containment, treatment, fixing the moisture source and drying so it does not come back. Onyx does remediation.
Can I just bleach it?
Bleach on a hard surface with surface-only growth can work. Bleach on drywall or wood does not reach roots, leaves the water behind and the growth returns. If it covers more than a small patch or is on porous material, it needs to be removed.
How long does mold remediation take?
Small contained jobs can be a day or two. Larger areas with drying and rebuild take longer. We give you a schedule after inspection and update it based on moisture readings.
Next step
Mold does not dry out on its own. Call for an inspection.
Free estimate. Insured crew. We find the water, remove the mold and rebuild. (267) 353-7953.
Call (267) 353-7953Not an emergency? Request a callback online and Onyx will call to confirm a time.