Basement Waterproofing Contractors in Philadelphia

Why Philadelphia Basements Flood

Philadelphia's housing stock is old, and a lot of it sits on stone or early concrete foundations that were never waterproofed. Add clay soil that holds water, poor grading that sends runoff toward the house, and hydrostatic pressure pushing groundwater through the walls, and basements leak. In rowhomes with shared walls and century-old stone foundations, it's rarely one leak, it's water finding the path of least resistance. We track down every entry point instead of sealing the one wet spot you can see.

We Fix the Cause, Not the Symptom

Plenty of companies will paint a sealer on your wall and call it waterproofing. That hides the problem until the next heavy rain. We're masons, so we read the foundation: whether the water is coming through cracks, over the footing, or up through the slab, and whether the wall itself is failing. Then we fix that. A coat of paint doesn't stop hydrostatic pressure; drainage and real repair do.

Signs Your Basement Needs Waterproofing

• Standing water, puddles, or damp spots after rain

• White, chalky efflorescence on the walls

• A musty smell that won't go away

• Cracks in the foundation walls or floor

• Bowing or bulging basement walls

• Mold or mildew on walls, framing, or stored items

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How We Waterproof a Basement

Inspect & Diagnose

We find every entry point and whether it's cracks, grading, or pressure driving the water.

Seal & Repair

We seal and inject cracks and repair failing sections of the wall.

Drainage & Sump

We install interior drainage and a sump pump to move water out for good.

Exterior & Grading

Where needed, we waterproof and regrade outside so water drains away from the foundation.

Verify

We confirm the basement stays dry before we call it done.

Why Philadelphia Homeowners Choose APS

We're a local, family-run crew, licensed, and we've waterproofed basements across Philadelphia since 2017 out of our shop in Huntingdon Valley.

• Licensed and insured, PA #139378
• Home Advisor Top Rated, Screened & Approved
• Masons who fix the foundation and the cause, not just seal the surface
• Interior and exterior waterproofing, drainage, and sump pumps
• Free, written estimates with a clear scope

Before you call, see the work. Browse recent jobs in our gallery and read our Google reviews. We'd rather you hire us because you've seen what we do.

A dry basement is the first step to a finished one. We also handle foundation repair, concrete repair, and basement remodeling across Philadelphia.

Areas We Serve

We waterproof basements across Philadelphia, Bucks County, and Montgomery County, including Chestnut Hill, Mt. Airy, Manayunk, Roxborough, Germantown, South Philly, Society Hill, Glenside, Jenkintown, Cheltenham, Gladwyne, and Huntingdon Valley.

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