Basement Waterproofing & Foundation Repair in NJ and Eastern PA
Down Under Waterproofing helps homeowners stop basement water, repair foundation damage, control crawl space moisture, and protect homes from long-term drainage and structural problems.
Based in Robbinsville, New Jersey, we provide basement waterproofing, foundation repair, crawl space encapsulation, French drain installation, sump pump systems, masonry repair, stucco repair, retaining wall repair, above-grade waterproofing, Bilco door services, historic home structural restoration, sill plate repair, and construction restoration throughout New Jersey and Eastern Pennsylvania.
Our work is built around local conditions, including heavy rain, groundwater pressure, clay soils, poor grading, aging foundations, crawl space humidity, older-home structural conditions, and seasonal freeze-thaw movement that affect homes across the region.
Waterproofing and Structural Repairs Designed for Local Homes
Down Under Waterproofing fixes wet basements, leaking foundation walls, sump pump failures, French drain issues, foundation cracks, bowed basement walls, crawl space moisture, masonry damage, stucco leaks, sill plate damage, rotted structural wood, and water-related structural problems throughout New Jersey and Eastern Pennsylvania.
We do not treat every leak or crack the same way. Our inspections look at the source of the problem: groundwater pressure, drainage patterns, grading, soil movement, foundation type, crack pattern, moisture entry, wood rot, masonry conditions, and structural symptoms. That helps us recommend a repair that addresses the cause of the issue, not just the visible damage.
PA #PA175894
Our Waterproofing, Foundation Repair, and Restoration Services
Homeowners call us for water problems, foundation concerns, crawl space moisture, drainage issues, older-home structural problems, and exterior repairs that require more than a surface-level fix. Below are the main services we provide across New Jersey and Eastern Pennsylvania.
Basement Waterproofing
Interior and exterior waterproofing, French drains, sump pump systems, wall seepage repair, cove joint leaks, foundation crack repair, and drainage improvements for wet basements.
Basement Waterproofing →Foundation Repair
Repair and stabilization for foundation cracks, bowed walls, block wall movement, poured concrete cracks, settlement signs, basement floor leaks, underpinning-related concerns, and structural moisture damage.
Foundation Repair →Crawl Space Encapsulation
Moisture-control systems for damp crawl spaces, humidity, odors, mold-supporting conditions, pest-supporting conditions, and structural wood protection.
Crawl Space Encapsulation →Above-Grade Waterproofing
Waterproofing for exterior wall leaks, failed sealants, flashing problems, stucco-related water intrusion, masonry leaks, and building-envelope water issues above the foundation line.
Above-Grade Waterproofing →Masonry, Stucco & Wall Repair
Repair for masonry deterioration, cracked walls, retaining walls, stucco damage, water intrusion, exterior wall problems, and structural or drainage-related wall concerns.
Masonry Repair →Historic Home & Construction Restoration
Structural restoration for historic and older homes, including sill plate replacement, floor leveling, termite damage repair, rotted wood replacement, support columns, beams, girders, floor joists, basement entryways, Bilco doors, and related moisture-damage repairs.
Historic Home & Construction Restoration →Common Problems We Help Homeowners Solve
Basement and foundation problems often start small, but they can become more expensive when water pressure, drainage problems, wood rot, masonry deterioration, or structural movement continue over time.
Water in the Basement After Rain
Basement water can come from wall seepage, floor cracks, cove joint leaks, sump pump issues, clogged drainage, grading problems, or groundwater pressure around the foundation.
Foundation Cracks or Bowed Walls
Horizontal cracks, stair-step cracks, widening cracks, and inward wall movement can be signs of soil pressure, hydrostatic pressure, settlement, or structural stress.
Crawl Space Moisture and Odors
Damp crawl spaces can contribute to musty smells, high humidity, wood damage, mold-supporting conditions, pest-supporting conditions, and poor indoor air quality.
Historic or Older-Home Moisture Damage
Older homes may develop sill plate damage, rotted beams, weakened joists, masonry deterioration, settlement symptoms, basement leaks, or crawl space moisture issues that need to be evaluated together.
Real Waterproofing and Foundation Repair Work for Local Homes
Every home has a different water and foundation story. Some properties need a French drain and sump pump system. Others need crack repair, crawl space moisture control, exterior drainage improvements, wall stabilization, masonry repair, sill plate replacement, or restoration after long-term water damage.
Our team evaluates the visible damage and the conditions behind it, including groundwater pressure, grading, drainage paths, soil movement, foundation type, wood rot, masonry conditions, and moisture patterns around the home.
We commonly help with:
- Wet basements after heavy rain
- Foundation cracks and wall seepage
- Bowed or cracked basement walls
- Failing sump pumps and drainage problems
- Damp crawl spaces and musty odors
- Historic and older-home moisture damage
- Sill plate, beam, girder, and floor joist concerns
- Masonry, stucco, and exterior water intrusion
Foundation Repair and Waterproofing Often Work Together
A wet basement is not always just a water problem, and a foundation crack is not always just a structural problem. In many homes, moisture, soil pressure, drainage, and foundation movement are connected.
That is why our inspection process looks at the full condition of the home. A leaking wall crack may need waterproofing and crack repair. A bowed block wall may need stabilization and drainage correction. A damp crawl space may need encapsulation, vapor control, drainage, or structural repair depending on what is happening below the home.
For historic homes, older homes, or homes with long-term moisture damage, the right repair may also involve evaluating sill plates, beams, girders, floor joists, rotted structural wood, masonry conditions, floor leveling needs, termite damage, or underpinning-related stabilization concerns.
Our goal is to identify the cause before recommending the fix
- Where water is entering
- Whether groundwater pressure is involved
- Whether wall movement or cracking is active
- Whether grading or drainage is contributing to the problem
- Whether wood rot, masonry deterioration, or older-home structural damage is present
- Whether the repair should include waterproofing, structural reinforcement, restoration, or a combination of solutions
Why Homeowners Choose Down Under Waterproofing
- Serving New Jersey and Eastern Pennsylvania since 2006
- Basement waterproofing and foundation repair expertise in one company
- Historic home, older-home, and structural restoration experience
- Repairs designed around local soil, groundwater, drainage, foundation, masonry, and moisture conditions
- French drain, sump pump, crawl space, structural, masonry, stucco, and restoration solutions available
- Free written estimates with clear recommendations
- Licensed, bonded, and insured for homeowner protection
- NJ Home Improvement Contractor License #13VH03267600
- PA Home Improvement Contractor License #PA175894
- Open Monday through Saturday, 7:00 AM to 7:00 PM
Trusted by local homeowners: Our reviews and project experience highlight communication, clean work, honest recommendations, and long-term waterproofing, foundation repair, and structural restoration solutions across New Jersey and Eastern Pennsylvania.
Reviewed by Homeowners Across New Jersey & Eastern Pennsylvania
Homeowners choose Down Under Waterproofing for clear communication, honest inspections, clean work, and long-term solutions for basement water, foundation damage, sump pump problems, crawl space moisture, masonry repair, historic home restoration, and drainage-related issues.
Recent Projects & Recognition
Real project examples and local recognition help homeowners understand the type of foundation repair, waterproofing, masonry, and structural restoration work Down Under Waterproofing performs throughout New Jersey and Eastern Pennsylvania.
Bowing Brick Wall Repair in NJ & Philadelphia
A bowed or cracked wall can be a sign of soil pressure, water pressure, or structural movement. This project explains how serious wall movement is evaluated and repaired.
View Bowed Wall Project →Princeton Foundation Repair Recognition
Down Under Waterproofing was recognized among top foundation repair companies in Princeton, NJ, reinforcing our local expertise in structural repair, waterproofing, and older-home foundation concerns.
View Princeton Recognition →French Drain vs. Sump Pump Guide
Many basement water problems require both water collection and water removal. This guide explains when a French drain, sump pump, or combined system may be needed.
Read the Waterproofing Guide →Service Areas in New Jersey and Eastern Pennsylvania
Down Under Waterproofing is based in Robbinsville, NJ and serves homeowners across Central New Jersey, surrounding New Jersey counties, and Eastern Pennsylvania.
New Jersey Counties
Mercer, Monmouth, Middlesex, Somerset, Hunterdon, Morris, and Ocean counties.
View NJ Service Areas →Pennsylvania Counties
Bucks County, Montgomery County, and nearby Eastern Pennsylvania communities.
View PA Service Areas →Local Home Base
Located in Robbinsville, NJ, we regularly serve Mercer County and nearby communities throughout Central New Jersey.
Robbinsville NJ Services →Visit or Contact Down Under Waterproofing
Down Under Waterproofing
274 Andover Place
Robbinsville, NJ 08691
Phone:(908) 812-5040
Email:support@duwaterproofing.com
Hours: Monday-Saturday, 7:00 AM-7:00 PM
We provide free estimates for basement waterproofing, foundation repair, crawl space encapsulation, drainage, masonry, stucco, historic home structural restoration, sill plate repair, and construction restoration services throughout New Jersey and Eastern Pennsylvania.
Popular service areas
Helpful Resources for Homeowners
Not sure what kind of repair you need? These guides explain common basement, drainage, foundation, and structural moisture problems in plain language.
Basement Waterproofing Cost in New Jersey
Learn what affects waterproofing cost, including basement size, water source, drainage needs, sump pumps, foundation condition, and repair complexity.
Read the Cost Guide →Interior vs. Exterior Basement Waterproofing
Understand when interior drainage, exterior waterproofing, sump pumps, or a combined solution may be appropriate for your home.
Compare Waterproofing Options →French Drain vs. Sump Pump
Learn how French drains and sump pumps work together and when each solution is needed for basement water problems in NJ and PA homes.
Read the Guide →Basement Waterproofing & Foundation Repair FAQs
Need Help With Basement Water, Foundation Cracks, Crawl Space Moisture, or Older-Home Structural Damage?
Tell us what you are seeing — water after rain, wall seepage, a failing sump pump, foundation cracks, bowed walls, musty crawl space odors, sill plate damage, rotted wood, masonry deterioration, or exterior water intrusion — and we will help determine the right next step.
Licensed & Insured | NJ License #13VH03267600 | PA License #PA175894 | Monday-Saturday, 7:00 AM-7:00 PM