French Drains, Sump Systems & Foundation Sealing.

Basement Waterproofing in Mercer County, NJ

Mercer County, NJ. Local masonry, restoration, chimney, and waterproofing since 1947. Dispatched from our Hamilton, NJ shop.

Mercer CountyNJ79+Years4Generations
Basement Waterproofing in Mercer County, NJ

Local To Mercer County

Mercer County Crew

Written Proposal

Fixed Total · Clear Scope

Family-Owned Since 1947

Four Generations · Paul-Led

By Paul Pennacchi·Owner, 4th Generation

Basement water problems in Mercer County track the age of the housing stock. Stone rubble foundations in Trenton and Lambertville, clay-heavy soil around Princeton, and postwar block foundations across Hamilton and Ewing each demand a different scope, and the diagnosis has to match what is actually in the ground. A. Pennacchi & Sons installs interior perimeter drainage, exterior excavation waterproofing, sump systems, and foundation sealing across every Mercer County town, with the root cause identified before any fix is quoted.

Mercer County: Our Basement Waterproofing Services In Mercer County.

Our Basement Waterproofing Services In Mercer County.

Interior Perimeter French Drain Installation: A trench is cut along the interior perimeter of your Mercer County basement, a perforated drain pipe is set on washed stone, and water is carried to a sump pump and ejected above grade. Exterior Foundation Excavation & Waterproofing: The foundation is excavated, cleaned, and sealed with a bituminous or polymer membrane, with a drainage board and perimeter pipe installed before backfill, the stronger option when full site access allows it. Sump Pump Installation with Battery Backup: A properly sized sump pump ejects collected groundwater above grade, while a battery backup keeps the system running during the power outages that often accompany Mercer County's heaviest storms. Foundation Crack Injection & Sealing: Active foundation cracks are sealed from the inside to stop water intrusion at the exact point of entry, addressing isolated leaks without the disruption of a full drainage system. Window Well Drainage & Sealing: Window wells are a common, overlooked water entry point in older Mercer County homes. We install proper drainage and sealing so each well stops directing runoff straight into your foundation. Concrete Floor Crack Repair & Resurfacing: Cracked or damaged basement floors are repaired and resurfaced to restore a solid, level surface, addressing both the cosmetic damage and any water path the crack may be creating. For a deeper technical breakdown of grade-specific methods, see our full guide to below and above grade waterproofing.

Mercer County: The Mercer County Properties We Waterproof.

The Mercer County Properties We Waterproof.

We waterproof basements in private homes throughout Mercer County. From aging block foundations in Trenton and Hamilton to older stone construction in Princeton Borough and newer builds on the high water tables common across Ewing, Lawrence, and West Windsor. Every scope starts with the actual failure point, not a system sold off a price sheet. Single-Family Homes, The call usually comes after a second or third wet basement event. A recurring damp corner, efflorescence on the block, or a sump pump that can't keep pace with a heavy storm. We identify where the water is entering and why before we recommend a fix. Historic and Pre-1950s Homes, Mercer County has some of the oldest residential stock in New Jersey. Stone rubble and unreinforced block foundations in Princeton, Pennington, and Hopewell were never built with waterproofing membranes. The repair has to work with what's there, not against it. Estates and Luxury Properties, Large homes in Princeton Township, Hopewell Valley, and the boroughs along the Delaware come with finished lower levels, mechanicals, and in some cases wine cellars or home theaters. A single wet season does real damage. These properties typically need exterior excavation and a full membrane system, not a drain tile patch. Townhomes and Attached Housing, Hamilton, West Windsor, and Robbinsville have significant attached and townhome inventory from the 1980s and 1990s. Shared foundation walls mean water management on one unit affects the next. We scope these with that in mind from the first site visit. Newer Construction on Problem Lots, Post-2000 construction across Lawrence Township and South Brunswick sits on soil that has had time to settle and shift. Builder-grade waterproofing degrades, grading moves toward the foundation, and water tables in low-lying areas do the rest. Age on the deed does not mean the foundation is sound. Learn more about our residential services.

Mercer County: Towns We Serve In Mercer County.

Towns We Serve In Mercer County.

From our Hamilton headquarters, we waterproof basements throughout Mercer County, including the towns below. Don't see yours listed? Call us, we likely still cover it. Hamilton · Trenton · Princeton · Ewing · Lawrence · West Windsor · East Windsor · Hopewell · Pennington · Hightstown · Robbinsville See our full New Jersey coverage

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What Our Clients Say

A Reputation Built On Referrals.

5.0
Countless Google Reviews
MA

Michael Atkin

8 reviews

10 Months Ago

Knowledgeable, professional, reliable. Sent 6 masons to get the waterproofing job done quickly. Highly recommended. Has the knowhow to get the job done right the first time. A trustworthy expert firm.

Basement Waterproofing
LH

Lauren Hilton

1 review · 1 photo

A Year Ago

I had a roofer come out for a small leak in my attic. He fixed it and while up on the roof took pictures of my chimney. Told me I had a big problem. Lot of mortar missing. I called A. Pennacchi & Sons. Paul came out the next day. He told me what needed to be done and gave me a price. I asked him if I should add a few bricks to the top. He said "why do you want to spend more money?" What contractor says that? The men came out a few days later. On time, polite, got right to work, and cleaned up like they were never there. Paul had given me a choice of colors. His price was the best one. My chimney now looks absolutely beautiful. I would give them 10 stars.

Chimney Repoint
RT

Rich Treichler

11 reviews

A Year Ago

Great experience with Paul and the Pennacchi team. We contracted this firm to waterproof our basement and replace our basement windows. Nick was excellent at coordinating the effort, including preparation, window replacement, waterproofing, clean up, and follow up to inquire about and resolve a few questions. Happy to recommend Pennacchi and Sons.

Basement Waterproofing
BG

Brenda Giannacio

1 review

A Year Ago

A. Pennacchi & Sons has offered outstanding service since our first meeting. Honest, reliable, knowledgeable, and very responsive. The staff take pride in their work and are very respectful of your home. We highly recommend using them if you are having issues with a wet basement. We cannot thank them enough.

Basement Waterproofing
JA

Jackson Adolph

2 reviews

A Year Ago

Pennacchi sealed our basement 2 years ago. After a recent heavy rain we noticed seepage and asked Pennacchi to look at it. They sent Nick, who did an excellent job diagnosing the problem, finding the most likely seepage site, and then repairing it. Nick came by the next day, inspected the repair, and also improved sealing of 2 utility pipe entries. The rapid response, competency, diligence, and follow-up were excellent.

Basement Waterproofing Repair
MA

Mmm Aaa

Local Guide · 19 reviews · 24 photos

2 Years Ago

We are so impressed with Pennacchi & Sons. Multiple people recommended this company as the best in the region. For a company with a huge legacy, working throughout the county, there was no hesitation to see what our small job looked like and whether they could help. The crew was friendly, timely, and efficient. Ray walked us through the process, gave us a play-by-play for the best understanding of the work, and answered tons of questions. The end result was better than the original.

Masonry Restoration
MS

Michael Su

Local Guide · 11 reviews · 1 photo

2 Years Ago

Pennacchi has an exceptional reputation and we now have firsthand experience of their stellar work. The precision craftsmanship and professionalism are impressive. We had our chimneys repointed, brickwork restored, and a basement wall resealed. It all blends seamlessly and looks gorgeous. Ask for Sam as your foreman if you can, he was amazing. The entire crew was fantastic. Kudos to Paul and the leadership for building a great team. Impeccable service and beautiful finished product.

Chimney & Basement Sealing
AA

Adam Arif

Local Guide · 98 reviews · 1,020 photos

2 Years Ago

Pennacchi & Sons does amazing work. They restored my front door steps which were in bad condition. They fixed all the chips and cracks and painted them. Very professional and great service.

Stone Step Restoration
VC

Victoria Chow

9 reviews · 9 photos

3 Years Ago

Water was getting into my house because of the old brick exterior. It needed to be repointed and painted on the interior. Although this was a very small job, Paul and his son Paul Junior were incredibly professional, listened, and addressed my concerns. I left their crew to complete the work without being home and everything was safe and secure when I got back. They kept their work areas clean and took away their trash. Paul’s price was the most competitive. HIGHLY RECOMMEND.

Brick Repointing
WR

Wayne Richardson

8 reviews · 1 photo

3 Years Ago

My basement was leaking really bad and had 2 different companies come out and try to fix the problem with no luck. Decided to try a third time and luckily I came across APS. They came out and did amazing work and solved all my issues. Put in a French drain, sump pump, and stuccoed the walls. They had to fix all the problems the other companies did, and it was a great experience working with them. Paul was extremely professional. Highly recommend if you need the job done right the first time.

French Drain & Waterproofing
SB

S. B.

Local Guide · 14 reviews

3 Years Ago

These guys did a great job on my chimney with stucco.

Chimney Stucco
SS

Shibani Sharma

8 reviews

3 Years Ago

Excellent work. Very professional.

General Masonry
ES

Ellen Scanlon

Local Guide · 13 reviews · 1 photo

5 Years Ago

Pennacchi is the best. We had several jobs done in the past few months and found Paul and team to deliver exceptional work and service for reasonable prices. Very knowledgeable and professional. We had the basement waterproofed, foundation redone, and steps repointed. Extremely satisfied.

Foundation & Waterproofing
BC

Bill Cunningham

Local Guide · 78 reviews · 265 photos

5 Years Ago

The best in the business. Ask for Paul. Tell him Billy C. sent ya.

General Masonry
KT

Katia Ten Eyck

Local Guide · 24 reviews · 69 photos

6 Years Ago

We hired Pennacchi and Sons to waterproof our basement. We did not necessarily have issues, we just wanted to prevent any moisture problems in the future. We consulted with a few other people before speaking with Paul, the owner. Paul came up with an effective and cost-effective solution for us. We are very happy with the service and highly recommend Paul to everyone.

Basement Waterproofing
JM

John Monsport

7 reviews · 1 photo

6 Years Ago

These guys did an amazing job for us. 20 years of trying to get my basement dry and these guys finally got it to work. We actually had another company do it 15 years ago but we always got water back. Paul and his brothers worked hard and they cleaned us up as well. Thanks for letting me tell this story guys.

Basement Waterproofing
MS

Mike Salvador

2 reviews

6 Years Ago

I hired Pennacchi and Sons to do repair work on my chimney. In the 3 days they were here, they did an excellent job from start to finish. They also left my home in the same condition as it was before they came. I could not recommend this company more and would definitely hire them again if I needed future masonry work done.

Chimney Repair
MB

MeghanB

16 reviews · 2 photos

6 Years Ago

Gorgeous job repairing and painting my chimney.

Chimney Repair & Paint
BK

B. K.

Local Guide · 56 reviews · 1 photo

6 Years Ago

You want the best, call Paul at Pennacchi & Sons. Great work and he stands by all his work. A++

General Masonry
MP

Marcus Padulchick

Local Guide · 102 reviews · 32 photos

7 Years Ago

I would use them again. We needed a front porch and patio repaired. They did a great job and are very responsive to follow up. Attention to detail is certainly something I was impressed with.

Porch & Patio Repair
Why Mercer County Owners Call Earlier

Every Mercer County Winter Adds Scope.

Mercer County masonry takes thirty to forty freeze-thaw cycles a year. Every cycle opens hairline mortar cracks wider, lets more water in, and deepens the eventual repair. The project you scope today is smaller than the one you will scope next year. The earlier you schedule a site visit, the smaller the proposal.

Interior vs. exterior waterproofing, which do I need in Mercer County?
Exterior waterproofing stops water before it reaches your foundation and is the stronger long-term fix when excavation is possible. Interior systems manage water that's already entering, using a perimeter drain and sump pump, and work reliably when installed correctly. Many Mercer County homes, especially in denser areas of Trenton and Hamilton, have limited exterior access, making interior systems the practical choice. A site visit determines which fits your property.
How much does basement waterproofing cost in Mercer County?
Cost depends on your system type, basement size, and whether the job is interior or exterior. Interior French drain systems generally cost less than full exterior excavation, since exterior work involves digging around the foundation. Mercer County's older housing stock, particularly in Trenton and Princeton, can add scope depending on foundation type. We provide a fixed-total written proposal after a free site visit, so cost is confirmed before work begins.
Will a sump pump alone solve my wet basement problem?
Not usually. A sump pump only ejects water that's already collected, it needs a perimeter drain feeding it to work effectively. A sump pump installed without a French drain is one of the most common failed waterproofing attempts we see in Mercer County basements, because it has no way to actually collect water reaching your foundation. Pairing a properly sized pump with a drain system is what makes it work long-term.
What causes basement leaks in Mercer County homes even when it's not raining?
Groundwater pressure, poor grading, and clogged gutters can push water into a foundation days after rain stops, as saturated soil continues draining toward the path of least resistance, often your basement wall. This is common in low-lying areas around Hamilton and Ewing where water tables run higher. Foundation cracks and window wells are common ongoing entry points. A proper diagnosis traces water back to its actual source.
Do I need a French drain, or is crack injection enough?
If water is entering through one isolated, active crack, crack injection alone may resolve it. If water is entering along multiple points, through the wall-floor joint, or you're seeing recurring dampness across a wider area, a French drain system is the more reliable long-term fix. A site visit at your Mercer County home is the only accurate way to tell which applies to your basement.
Will homeowners insurance cover basement waterproofing?
Most standard homeowners insurance policies do not cover basement waterproofing, since they typically exclude gradual water seepage and groundwater intrusion, treating it as a maintenance issue rather than sudden damage. Coverage can vary by policy and insurer, so it's worth checking your specific policy language. Some insurers offer optional water backup or sump pump failure endorsements, which differ from waterproofing installation. Confirm directly with your insurance provider before assuming coverage.
Start Your Project

Ready To Discuss A Project In Mercer County?

Call the Hamilton headquarters or submit the form. A specialist replies promptly to confirm scope and schedule a Mercer County site visit.