Solving Water and Structural Problems at the Source
Down Under Waterproofing is a foundation repair and waterproofing contractor serving New Jersey and the greater Philadelphia area. With over 20 years of field experience, we work with homeowners, property managers, and structural engineers to address complex masonry and structural issues.Our work focuses on both structural stabilization and moisture control, including bowing brick wall repair, foundation reinforcement, basement waterproofing, and masonry restoration.
In older and historic buildings, water intrusion and structural movement often go hand in hand. We identify the root cause of failurewhether its deteriorated mortar, failed joist bearing, or lack of lateral supportand implement repairs that restore both structural integrity and building performance.
Our projects often involve coordination with engineers, permits, and inspections, ensuring that all work meets current structural and code requirements.
We serve residential and light commercial properties throughout New Jersey and the Philadelphia region.
Served areas
- Mercer County, NJ, Monmouth County, NJ, Middlesex County, NJ, Somerset County, NJ, Hunterdon County, NJ, Morris County, NJ, Ocean County, NJ, Bucks County, PA, Montgomery County, PA, Philadelphia County, PA
Business details
- Year established: 2006
- Employees: 10
- Licensed
- Insured
Highlights and features
- Foundation repair
- Basement waterproofing
- Bowing wall stabilization
- Structural star bolt installation
- Masonry repair and repointing
- Historic home structural repair
- Drainage and moisture control solutions
- Engineer-coordinated structural work
Associations and certifications
- Fully licensed, bonded and insured
- Works with structural engineers
- Permitted structural repair projects
- Historic property repair experience
Payment methods
- Cash, Checks, Debit cards, Credit cards, Mobile payments, Financing available
Services
We provide basement waterproofing services including French drains, sump pump installations, crack repairs, and moisture control sealing and painting. We emphasize protecting your home by selecting appropriate systems installed by professionals. Our solutions reduce hydrostatic pressure and help prevent basement flooding. We also address dampness issues that can impact air quality and structural materials. 
We provide above-grade waterproofing solutions that protect exposed building elements from rain wind and UV exposure. Our services focus on preventing water intrusion through the building envelope using professional coatings caulking and flashing systems. We ensure durability against weathering and temperature changes. Our work supports long-term structural performance and reliability. We ensure lasting protection outcomes 
We offer crawl space encapsulation to prevent moisture damage and improve indoor air quality. Dirt crawl spaces promote insects, mold, mildew, and harmful spores affecting structural integrity overall. Soil moisture and natural airflow pull humid air and contaminants into living areas. Encapsulation isolates crawl spaces, reduces humidity, and helps restore significantly healthier home conditions overall. 
We provide foundation and structural repair across New Jersey and Eastern Pennsylvania, addressing issues including cracks, bowing walls, and water intrusion. Our team identifies root causes including hydrostatic pressure, soil movement, and drainage failure, delivers long-term repair solutions using proven stabilization and reinforcement methods. Coordinate inspections, permits, and engineering support to ensure lasting structural integrity. 
We provide restoration for residential and commercial properties affected by water, fire, wind, or emergencies. Our team assesses, plans, and manages project, including permits, utilities, and personnel, with safety and efficiency. We maintain scheduling, financial oversight, and communication with reporting throughout each project. No project is too large or small, and we deliver restoration solutions. 
We provide egress windows and basement doors that comply with current building codes and safety standards. Egress systems are designed for emergency escape and first responder access in finished basements while basement doors offer entry and allow large items to be moved. Our solutions balance functionality, natural light, ventilation and designs to fit different homes and budgets. 
Masonry is durable yet requires repair due to ground movement and temperature changes. Weather exposure in New Jersey and Eastern PA causes mortar deterioration and moisture intrusion, weakening structural integrity. We remove failed mortar and perform tuckpointing to restore brickwork. We offer wall crack, stone, retaining wall, staircase, and chimney masonry repairs with expertise. 
We design and install retaining walls that support soil and manage elevation changes. These structures help control erosion and stabilize steep or uneven landscapes. They also enhance outdoor spaces with functional and aesthetic landscaping solutions. We offer multiple material options, and the best choice depends on project needs, budget, and design requirements.
Reviews (20)
Alexandria Fazzari
Mar 20, 2026
We hired Down Under Waterproofing for a large project in our basement and in our yard, which included everything from encapsulating the basement, repairing some foundation, adding a window well, some aesthetic work etc. to moving our cellar door. Everyone who we dealt with from the projects inception to the end was very communicative, helpful, and respectful. Prices were fair and the work is great & neat. Everyone who came through our house during the project commented on what nice work they do. I even overheard a town inspector complimenting their work. Highly recommend Walt and his workers!
Mtc
Feb 26, 2026
These guys are the real deal! I had an issue that was stressing me out and wondered how in the world can I get this repaired. After a few phone calls to 800 numbers answered by operators I came across Down Under Waterproofing. Would you believe an actual knowledgeable person answered the phone "Hello this is Walt" I already felt better. I explained my situation and then next day Walt showed up. He looked at the job gave me a very fair quote and that same week I was scheduled. Max and the crew were polite, hard working, and respectful of my house. They really made what I thought was impossible look easy. Couldn't be happier, thank you!
BarbAra Vetter
Feb 19, 2026
Walt, Max and their team were superb! Been meaning to post a review for awhile, just figured how to do it! I wouldn't have tried to figure this out for any other company but for Walt and his team! Professional, precise and definitely best price compared to other companies. On top of that, Max got his team to finish a day earlier than expected. Oh, they did a french drain in my basement, waterproofed a small section of my foundation and waterproofed a wall under our deck. We are super happy with their work and will refer them to anyone who needs their services. Thank you Walt, Max and your whole team.
Vinny Stavola
Feb 17, 2026
Walt is true professional! His crew replaced 35 ft of sill plate and joists from under the crawl space and 2 by 4s. He took out 9 windows and reflashed them with treated wood. There was brick on outside besides siding and waterproofed that too. Small bumps in the road on things not visible to the eye and he was more than fair with price!
If anyone needs waterproofing this is your team. His manager Max led the team and and he showed up everyday! Thank you guys
If anyone needs waterproofing this is your team. His manager Max led the team and and he showed up everyday! Thank you guys
Jamie Kris
Feb 13, 2026
Lortech C. E.
Feb 05, 2026
Lortech has been working with Down Under Waterproofing for over 15 years. Down Under implements foundation repairs and underpinning per our design plans. I have always found their work to be above par and when job conditions require plan changes, they are always receptive and willing to make adjustments as necessary.
Monica Mckenzie
Jan 29, 2026
Down Under Waterproofing was one of the best experiences I have had with any contractor. I had a crack in my basement foundation ( old house from 1850 so not an easy job) and they were able to immediately assess the damage, provide me with multiple options and execute the repair in a seamless fashion. They also sealed all my basement walls. The work was flawless! I also appreciated that they kept everything tidy and left no residual mess in the house. I cannot recommend them enough!
Toni Tarallo
Dec 11, 2025
I am so glad I went with Down Under! Walt came out promptly to assess my water issue, patiently answered all my questions and quickly returned my call when I had even more after another company got to me with scare tactics. You wont get that with Walt. Max was here on the day of the job and again explained the process. The entire crew was professional and respectful. They took care to limit the dust and left me with no mess.
They deserve a shout out! I can honestly say I wouldnt call anyone else if I have any other problems. I can finally put away the shop vac and not worry every time it rains. Thank you!
They deserve a shout out! I can honestly say I wouldnt call anyone else if I have any other problems. I can finally put away the shop vac and not worry every time it rains. Thank you!
Rebecca Gardner
Nov 27, 2025
Walt is quick to respond and in a timely fashion provided a quote for foundation work that we needed in order to secure our homeowners insurance. When we did the work, over the course of the five day job the crew was prompt, courteous and cleaned up as much as possible. This is the second time we worked with them.
Dawn Ritter
Oct 15, 2025
Thomas Marian
Oct 14, 2025
Robin Willever
Oct 14, 2025
David Piccolo
Sep 27, 2025
Walt and the team did a fantasy job putting in French drains in our home this summer. Our basement looked like complete crap and always had water/dirt coming in as we are on a hill. I called Walt and he explained everything very clearly - he knows his stuff. They put in a French drain, a new sump pump, and some new wood to seal the top of our basement. Our basement has not had any issues since. As a big plus, the staff was very kind and you hardly noticed they were there. Highly recommend.
Barbara Piccolo
Sep 06, 2025
I had a major foundation problem and Walt and his crew were phenomenal. They replaced a large section, placed rebar in the rest and waterproofed everywhere. They were amazing! The crew is so respectful, Max, the foreman in my job is kind and responsive. The owner, Walt, is great at responding to any questions or issues. It is with complete confidence that I recommend Down Under Waterpfroofing.
Marie Brooks
Jun 04, 2025
Walts team came to install a French drain and sump pump for me in 2021 after the house I just purchased flooded in the basement (it had been flipped without proper water management). We had to tear up brand new floors! The sump pump and fence drain worked great for us for years. Several weeks ago (2025) we very surprisingly got some water in the very center of the basement under the stairs after weeks of heavy rain and Walt came out that day. It was a perplexing situation for everyone, but Walt sent his team out free of charge to lay down additional drains in the center of the basement. I was very impressed with the quickness to take accountability and resolve the issue - no hassle. I absolutely recommend Walt and his team.
Mikayla Schmitt
May 17, 2025
Walt and his team did an amazing job at repairing my foundation and addressing some drainage issues. From the start Walt was knowledgeable and fair with his pricing. Being a young homeowner, finding a good contractor can be difficult, but Walt made the entire process easy. He answered any and all questions I had, meanwhile project manager Max communicated with me effectively and efficiently about all the work being done. Their team put in a new sump pump and French drain system as well, and everything looks and works amazing. I highly recommend giving Walt a call before any other company.
Ron
May 14, 2025
What a pleasure it was to work with Down Under Waterproofing. Walt the owner came out and explained what had to be done with my basement and was upfront with the price. The crew that worked on my home was very professional and knowledgeable. Walt touched base with me entire job to make sure I was satisfied. I would definitely recommend Down Under Waterproofing.
Paul
May 09, 2025
I have used Down Under Waterproofing and Foundation Repair for multiple French drain installations at my properties and have always been extremely satisfied with their work. The sales team and leadership (Walt and Max) are friendly, professional and provide fair pricing. The quality of their work is excellent and I would highly recommend them for any foundation waterproofing or structural foundation projects. I will definitely be using them for future projects.
Helene Louise V.
Jan 17, 2025
I have used Down Under for four projects now, because they are wonderful to work with, have great prices, and I have come to trust Max completely. Most recently they have replaced our wooden deck with composite decking materials, reinforcing the posts and replacing the rails and steps, and reattached the existing awning poles without trouble. It looks beautiful and will outlast us!
Joe Chiao
Jan 07, 2025
Walt and his foundation waterproofing and repair team did a wonderful job. We had two separate basement leaks due to cracks in our poured concrete foundation. They were able to complete the foundation repair work inside the two finished basement areas and restored the drywall like new after the repairs. The outside work seemed more complicated with one area under a paved patio, yet it was done quickly and restored afterwards like nothing happened. Walt and his team even went the extra mile to ensure preventive measures were implemented to both areas, by placing drains underground in both areas, as well as one above ground Highly recommended without reservation. The work was done quickly, professionally and with quality and great communication.