What counts as the plumbing side of waterproofing
Water reaches a basement in a few ways: through the floor, through the walls, up through floor drains, or from a leaking pipe. Waterproofing contractors usually work on the first two from the outside. Plumbers manage what happens once water is in, and keep sewer water from coming up a drain.
The plumbing tools are a sump pit with a pump, interior perimeter drains that route water to the pit, backwater valves, floor drain repair and cleaning, and checking whether a leaking pipe is the real source. We start by finding which of these applies, because the fix differs for each.
Over 69% of Horsham homes were developed between 1950 and 1990 per the township plan draft, so many basements are 35 to 75 years old and their original drains and pits deserve a look first.
Where is the water coming from?
Water at the wall-floor joint after rain
Groundwater is pushing in at the cove joint. A perimeter drain and sump pump can collect and remove it.
Damp patch with no rain
A supply or drain leak, a condensation problem, or a water heater can all do this. We check pipes first.
Water from a floor drain
This can be sewer backup or groundwater rising through the drain. The two need different fixes.
Puddle by the water heater or washer
Appliance connections and drain pans fail often. These are plumbing leaks.
Efflorescence and musty smell
White mineral deposits and odor show repeated moisture, but not whether it enters from outside or inside.
Interior drains and sump pits
An interior drain system collects water at the footing level and sends it to a sump pit. The pit holds a pump that discharges outside. This approach manages water that has already passed the wall, which is different from stopping it outside.
We handle the pit, the pump and discharge piping, and can open the slab for drain lines where that is part of the plumbing scope. For the pump itself, see sump pump repair, where we cover failure causes, battery backup and storm readiness.
A sump pit and a sewage ejector pit are not the same thing. A sump pit takes in clear groundwater, while an ejector pit receives wastewater from a basement bathroom or laundry and lifts it to the sewer line. Mixing them up is a common mistake, so we check what feeds each pit before we change anything.
Need a plumber to read your basement?
We can tell you whether the water is a plumbing problem, a drainage one, or something for a waterproofing contractor. Call (215) 714-6692.
Backwater valves and floor drains
A backwater valve is a one-way valve on the sewer line that closes when sewage flows backward. It protects basement fixtures from a municipal sewer surcharge or a clogged main. It needs periodic cleaning so the flap moves freely.
A backwater valve sits on the building lateral, which belongs to the owner, while the Authority owns the service lateral out to the right-of-way or easement line. If sewage is coming up a floor drain, call the Authority at (215) 672-8011 first because checking the street main is free.
Whether a valve is required depends on your property, so ask Code Enforcement at (215) 643-3131. A floor drain that never gets water can dry out and let sewer gas rise, so we refill traps and clear clogs.
Where the plumbing work ends
Plumbing side
- Sump pits, pumps and discharge piping
- Interior drain connections tied to the pit
- Backwater valves and floor drain service
- Finding pipe leaks that wet the basement
Exterior waterproofing contractors
- Dig out and expose exterior foundation walls
- Apply exterior waterproof membranes or coatings
- Repair foundation cracks or underpin walls
- Regrade yards or install exterior drainage
If we find that the water enters through the foundation wall or a poorly graded yard, we say so. You would need a waterproofing or foundation contractor, and we can still handle the interior pit and pump that go with their work.
How we assess a wet basement
- 1
Walk the basement
We look at floors, walls, the pit and drain lines, then mark damp spots and note stains and mineral deposits.
- 2
Rule out pipe leaks
We run a meter test and inspect supply lines, drain lines, the water heater and appliance connections.
- 3
Check drains and the sewer line
We test floor drains, and where needed, run a camera. See our sewer camera inspection service for backups.
- 4
Recommend the plumbing fix
We explain what plumbing can solve, what it cannot, and how the options stack.
Dealing with a wet basement before the visit
Practical steps while you plan
- Move stored items onto shelves or pallets, off the floor
- Note when water appears: during rain, after laundry or at all times
- Keep downspouts discharging away from the foundation
- Photograph the wall, the floor and any stains
- Run a dehumidifier to measure whether moisture is dropping
These steps do not waterproof a basement, but they help sort out cause. If water is rising now, call about sump pump repair. A pipe leak that is wetting the wall is a job for leak detection.
What affects the price of plumbing-side waterproofing
The price is spelled out before work starts. The biggest factors:
Slab cutting
Interior drains and backwater valves need concrete cut and patched.
Length of drain line
A short sump-only system differs from a perimeter drain.
Pump and backup choice
Primary pumps, battery backups and water-powered units differ in cost.
Discharge route
Distance and rules for where water goes change piping needs.
Condition of existing pit and lines
Old pits, clogged lines and cracked pipes expand the scope.
Insurance coverage for groundwater and sewer backup varies by policy. Ask your carrier before you file. Want your real number? Call (215) 714-6692.
When rain is the trigger
Water that appears only during or after heavy rain is almost always a drainage problem, not a plumbing leak. The township sits in three watersheds, Neshaminy, Pennypack and Wissahickon, so lot grading differs from street to street.
Note which side of the house the water appears on, and the date. The National Weather Service called the remnants of Ida on September 1, 2021 catastrophic flash flooding. A log of what happened in a storm like that helps any contractor.
Working with other contractors
Many basement fixes combine trades. A waterproofing contractor handles the exterior and the wall. We handle the pit, pump and drain connections, and we coordinate on timing so the interior system works with what they build. If you plan to finish the space afterward, the township permit page lists finished basements as needing a permit, so settle the water first.
We serve homes across Horsham and nearby towns including Warminster and Maple Glen.
Questions about basement waterproofing in Horsham
Not from outside. Exterior excavation and coatings belong to waterproofing contractors. We handle the plumbing side: sump pits and pumps, interior drains, backwater valves and floor drains.
A pump removes water from the pit, but it needs drains or a high water table feeding it. Our assessment shows whether plumbing alone can handle your case.
A one-way valve on the building lateral that closes when sewage tries to flow backward, so it does not enter low fixtures. It needs a clean flap to work. The Authority says basic homeowner policies often exclude sewer backups, so ask your agent about coverage.
The trap may have dried out, letting sewer gas rise. Pouring water in often helps. If it recurs, the trap or the line may need service.
Water appearing only after rain suggests groundwater. A constant damp area, or a meter that moves with fixtures off, suggests a pipe leak.
Our work covers the plumbing source. Mold cleanup and wall repair are separate trades.
It can depend on the work. Ask Code Enforcement at 1025 Horsham Road, (215) 643-3131, what applies to pumps, drains and valves. Finished basements are listed on the township permit page as needing one.
Sources we checked
Local facts on this page come from these public pages. Plumbing work in Pennsylvania falls under the Uniform Construction Code, which adopts the International Plumbing Code (IPC) provisions, so ask Horsham Code Enforcement which edition applies before a permit is pulled. Rules and phone numbers change, so confirm with the office before you act.
- horshamwater-sewer.com/sites/default/files/2026-02/horsham-water-se... Authority report
- horshamwater-sewer.com/sewer-backups Authority report
- horsham.org/10737/Permits Township page
- horsham.org/10515/stormwater-management Township page
- weather.gov/phi/eventreview20210901 State agency
- files.municipalone.com/horsham-pa/781020345012125pm.pdf Township page