Flooded basement
Flooded Basement Cleanup in Philadelphia
Water in the basement from a storm, a sump failure, a burst line or a sewer backup. Onyx extracts it, dries the space to the meter, and documents every step for your insurer.
- IICRC certified
- 24/7 emergency response
- Insured
- 17 years in restoration
- Free estimates
- Works with your insurance
Basement flooding in Philadelphia comes down to a short list of reasons: heavy rain overwhelming a sump or drain, a sewer line backing up, a water heater or supply line letting go, or groundwater coming through a rowhome foundation that was never meant to be finished living space. Whatever the cause, the water is now under the flooring, in the bottom of the drywall and inside anything cardboard.
Onyx starts by figuring out where the water came from, because that decides how we treat it. Clean supply water and a sewage backup are handled very differently. Then we extract, remove what cannot be saved, dry the structure and rebuild.
Stop before you step in
A flooded basement can be an electrical and a health hazard before it is anything else.
- If water is anywhere near outlets, the panel or a plugged-in appliance, do not walk in. Call the utility or an electrician to kill power first
- If it smells like sewage or came up through a floor drain, treat it as contaminated. No bare skin, no kids, no pets
- Shut the main water supply if the source is inside the house
- Do not run a household vacuum or a box fan on standing water
- Take photos and a short video from the stairs before anything is moved
Basement water removal: what we do
Pumping the water out is the easy part. The damage is in what stays wet afterward.
- Pump and extract standing water from slab, carpet and finished flooring
- Identify the water category: clean, gray or sewage, and set containment to match
- Remove saturated carpet, pad, baseboard, lower drywall and insulation
- Meter the slab, framing and walls; thermal imaging finds the moisture you cannot see
- Place air movers and dehumidifiers and monitor until readings hit dry standard
- Disinfect for gray water and sewage losses
- Rebuild: drywall, flooring, trim and paint once the basement is verified dry
Rowhomes, twins and finished basements
Most Philadelphia basements are below grade, share party walls and carry the utilities. Water that sits behind a party wall affects the neighbor too. A finished basement with a bedroom or rental unit is a bigger loss than an open cellar, and the drying plan is different.
We have worked in narrow South Philly and Kensington basements where the only access is the interior stairs and equipment has to be sized to fit. Tell us what kind of house you have when you call.
Sump pump failure
A sump pump that fails during a storm or a power outage can flood a basement in hours. We extract the water, dry the space, and document the failure for your claim. Many policies need a sump pump or water backup endorsement to cover it, so check your policy and keep the failed pump.
Sewage backup cleanup
When the city sewer or your lateral backs up, the water in your basement is contaminated and has to be handled as category 3 water. The full guide covers what to do, who to call and insurance.
What you may be seeing
- Standing water on the basement floor after rain
- Water coming up through the floor drain
- Sump pump running constantly or not at all
- Damp carpet, swollen baseboard, a musty smell that does not clear
- Efflorescence (white powder) or dark staining on block walls
How it goes
What happens after you call.
Call and make it safe
We ask about power, the source and the smell. If it is unsafe to enter, we tell you so and coordinate the shutoff.
Extract
Pumps and extractors pull the standing water. Contents that can be saved come up and out of the wet zone.
Demo and containment
Wet carpet, pad, lower drywall and anything porous that touched contaminated water is removed and bagged.
Dry and monitor
Air movers and dehumidifiers run while we meter the slab and framing every visit until they read dry.
Rebuild
Onyx puts the basement back, and can rebuild with more water-tolerant materials if you want to plan for the next storm.
Proof
On the job
Metering, drain cleanup and material removal on Onyx basement and residential water jobs.
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 a flooded basement cost to clean up?
It depends on how deep the water was, whether it was clean or sewage, how long it sat, and whether the basement is finished. A few inches of clean water on a bare slab is a small job; a sewage backup in a finished basement is a large one. Onyx gives free written estimates after metering the space. See our water damage cost guide for the factors that move the number.
Is it safe to walk in a flooded basement?
Not until you know two things: that the power is off to anything the water can reach, and what kind of water it is. Electrocution and sewage exposure are the two real risks. If in doubt, stay on the stairs and call.
What are the dangers of standing water in a basement?
Electrical shock, bacteria and sewage contamination, and mold. Mold can start growing in porous materials within a couple of days, and standing water wicks up drywall and framing the longer it sits. Speed matters more than almost any other factor.
Does insurance cover water damage in a basement?
It depends on the cause. Sudden events like a burst pipe or failed water heater are commonly covered. Groundwater, surface flooding from rain and sewer backup usually need separate flood or backup coverage. We document the source and the damage so your adjuster can make the call with a full record.
Can you handle a sewage backup in the basement?
Yes. Sewage is treated as contaminated water: containment, removal of everything porous it touched, disinfection and drying, with the crew in proper PPE.
My sump pump failed during a storm. Can you help?
Yes. We extract and dry the basement. Replacing or upgrading the pump itself is plumbing work we can coordinate with you during the rebuild.
Does insurance cover sump pump failure?
Often only if your policy includes a sump pump or water backup endorsement. Coverage is your insurer's decision; we document the damage and the failed pump for your claim.
Next step
Water in the basement? Stay out of it and call.
Free estimate. Insured crew. We document everything for your claim. (267) 353-7953.
Call (267) 353-7953Not an emergency? Request a callback online and Onyx will call to confirm a time.