Targeted repair
$2k–$7k
- Crack injected with polyurethane
- Downspouts extended 6 to 10 feet
- Soil regraded away from the wall
- Window well cleared and covered
- Sump pump replaced if failing
- Photos before and after
Basement waterproofing · Licensed & insured · Same-week inspection
Basement waterproofing that finds the source first, then fixes only what it has to.
Water in a basement comes from a handful of places: the grading, the gutters, a crack, the joint where wall meets floor, or water pressure under the slab. A licensed supervisor finds which one it is this week, photographs it, and gives you a written price for the smallest fix that will actually stop it.
Water on the floor right now? Text a photo and a supervisor replies within 5 minutes during business hours and sets the inspection.
- $9k–$18kInterior drain + sump
- 2–4 daysInterior install time
- 4.9410 reviews
- 24hWritten estimate
What happens after you text us
Send one photo of the water. We will know where to look first.
Where the water sits on the floor says a lot about where it comes in. The supervisor asks for one photo, one question about gutters, and books an inspection this week, sooner if water is on the floor now.
- The water pattern on the floor points to the likely source
- Gutters and downspouts are checked before anything is sold
- Inspection booked within days, not weeks
We got water in the basement last night after the storm. It is along the back wall, a strip about two feet wide.
Hi Steve, this is Brian, I run our waterproofing crews. A strip along the wall usually means water coming in where the wall meets the floor. Could you send a photo, and tell me where the downspouts on that side end?
Photo sent. The downspout on that corner just dumps next to the house.
That is a likely cause. Extending it may fix most of this for a few hundred dollars, but I want to check the wall for cracks too. I can be there tomorrow at 8. Can you run a fan and a dehumidifier until then?
Yes, tomorrow at 8 works. Will you try to sell us a whole system?
Only if the small fixes will not do it. You will get the cheapest option that works and, if needed, the bigger one, both in writing.
What basement waterproofing costs
Basement waterproofing costs $2,000 to $45,000. The source of the water decides which one you need.
About a third of the wet basements we inspect are fixed by the targeted repair alone. The interior system is the most common full fix, and exterior excavation is kept for walls with serious water pressure or damage.
Interior drain and sump
$9k–$18k
- Slab cut along the wall edge
- Perforated drain in stone
- Dimple membrane on the walls
- Sealed sump with a new pump
- Battery backup pump
- Slab patched and cleaned up
Exterior excavation
$20k–$45k+
- Excavation to the footing
- Walls cleaned and repaired
- Membrane on the outside wall
- New footing drain to daylight
- Backfill with drainage stone
- Landscaping restored to grade
Estimate your waterproofing cost
Choose the fix, the length of wall affected and the type of foundation. The range moves as you choose, using the tiers our inspectors price from.
A range, not a quote. Your written estimate comes after the visit and does not change once you approve it.
Typical range for your answers
Turn this range into my written fix priceWhere the money goes
Cutting and digging take the largest share. The pump is one of the smallest.
Averages from our recent interior drain and sump installs. Most of the cost is the labor of cutting the slab, trenching and hauling out broken concrete and soil, which is why the length of wall matters more than the pump model.
Get my itemized waterproofing price
Targeted repair or full system
Fix the one source when there is one. Install a full system when water comes from everywhere.
A downspout extension costs a few hundred dollars and a full interior drain costs thousands. We never sell the second when the first will do. At the inspection we check six things and write down which answer fits your basement.
| What we find at the inspection | We recommend |
|---|---|
| Water enters at one crack in a poured wall | Targeted repair |
| Water seeps along the base of most walls | Full system |
| A downspout empties right next to the wet spot | Targeted repair |
| Water rises through the floor in spring | Full system |
| The ground slopes toward the house on one side | Targeted repair |
| Block walls show damp streaks on several sides | Full system |
How long it takes
An interior drain and sump take two to four days, and the basement is usable at night.
A targeted repair takes one or two days. Exterior excavation takes one to two weeks depending on depth and weather. If water is on the floor now, we inspect within days and can install a temporary pump the same visit.
Within days
Inspection and diagnosis
Walls, floor, gutters and grading checked, moisture measured, source photographed, written price sent.
Day one
Protect and cut
Belongings moved, dust walls up, slab cut along the wall, broken concrete hauled out in sealed bags.
Days two and three
Drain, stone, sump
Drain pipe set in clean stone, membrane on the walls, sump basin and pumps installed and tested.
Final day
Patch and water test
Slab patched, basement cleaned, hose test with you to show water reaching the sump, warranty handed over.
Before and after
Three wet basements, dry through the next storm.
What your basement system is made of
Every pump and membrane is named, so you can check it yourself.
Waterproofing quotes often say system without saying which. Ours names the pump, the backup, the membrane and the crack sealant, so you can compare quotes and look up any part.
Sump pumps
Zoeller or Liberty cast iron pumps sized to your water volume, in a sealed basin with a lid that keeps moisture and radon out of the room.
Battery backup pumps
Basement Watchdog or Zoeller backup pumps take over when the power fails in a storm, and sound an alarm when they start.
Dimple membrane
Cosella-Dorken Delta-MS dimpled sheets on the inside of the walls guide seeping water down into the drain instead of across the floor.
Crack injection
Two-part polyurethane injected into the crack expands to fill it through the full wall thickness and stays flexible as the wall moves.
Exterior membranes
Tremco Tuff-N-Dri or similar rubberized coatings with drainage board go on the outside of the wall when we excavate.
Drain pipe and stone
Four-inch perforated pipe wrapped in filter fabric and set in washed stone, so fine soil does not clog it over the years.
Written into every contract
Six promises you can hold us to.
The approved price is the final price. Change orders only with your written approval.
A credit for every working day of delay we cause. Weather and inspections excepted, in writing.
Dust barriers, floor protection and a clean-up before we leave. Your home stays livable.
A text or email every working day with photos and tomorrow's plan, or the day is free.
Workmanship warranty in writing, transferable to the next owner, backed by a fixed address.
A small deposit, then you pay only for work that is already completed, inspected and photographed.
Who is in your house
Three people fix the water, and one of them diagnosed it.
The supervisor who inspects your basement leads the crew that fixes it, so nothing gets lost between a salesperson and an installer. Everyone is background-checked and introduced by name.
Waterproofing supervisor
Finds the source, writes the price, leads the install.
Concrete and drain installer
Cuts the slab, lays the drain and patches the floor.
Licensed plumber
Sets the sump, the pumps, the check valve and discharge.
Recent waterproofing jobs, real numbers
Three wet basements, three fixes, each sized to the problem.
Downspouts and regrading
- Final price
- $3,400
- Duration
- 1 day
- Location
- City, ST
Interior drain on two walls
- Final price
- $13,800
- Duration
- 3 days
- Location
- City, ST
Exterior membrane, one side
- Final price
- $27,600
- Duration
- 8 days
- Location
- City, ST
Your basement is not average
Why your basement is wet changes what we recommend.
The three tiers above cover most wet basements. These are the situations we see most often, and how each one changes the scope, the cost or how fast we need to move.
Water on the floor right now
When water is rising, speed matters more than the full fix. We inspect within days, set up a temporary pump or clear the sump on the first visit, then price the permanent repair once the basement is dry enough to read.
Book my urgent basement inspectionAn inspection report flagged it
A buyer's inspector noted efflorescence or a damp wall. We inspect, tell you in writing whether it is an active leak or old history, and price a fix backed by our written workmanship warranty you can show the buyer.
Answer my home inspection findingBefore finishing the basement
Finishing over a basement that still gets wet ruins the drywall and flooring. We test the walls and slab first, fix the source, and only then hand off to finishing, so you never pay for a finished room twice.
Waterproof before I finish my basementA stone or block foundation
Fieldstone and hollow block walls let water through in many places at once, so a crack repair rarely solves it. An interior drain with a membrane usually does, and we price any mortar repair the wall also needs.
Price my older foundation fixWater only in big storms
If water appears only in the heaviest rain, the gutters, downspouts and grading are usually the cause. We fix those first for a few thousand dollars and hold off on a full system until we see whether it works.
Fix my storm-only basement leakWater damaged your belongings
Insurance often covers sudden damage, such as a failed pump, but not gradual seepage. We document the cause with photos and a written report you can send to your adjuster, and fix the source either way.
Document my basement water damageSnowmelt every spring
In cold regions, frozen ground and melting snow push water against the walls every spring. We extend downspouts past the frost zone, protect the discharge line from freezing and size the sump for the melt.
Prepare my basement for snowmeltKeeping the cost down
We always start with the cheapest fix that could work: gutters, downspouts, grading and a single crack. About a third of the time, that is all it takes. You only pay for a drain system if the water keeps coming.
Start with my lowest-cost fixWhat this service is
Basement waterproofing, sized to the source of the water.
Basement waterproofing is the diagnosis and repair of water entering a basement through walls, cracks, the wall and floor joint or the slab, using the smallest effective fix: gutter and grading work, crack injection, an interior perimeter drain with a sump pump, or an exterior membrane with a new footing drain. ProBuild Remodeling does it as a licensed general contractor.
It covers inspection, moisture measurement, targeted repairs, interior drain and sump systems with battery backup, wall membranes and exterior excavation with membrane and drainage. It includes permits where a discharge line or excavation needs one. It does not include structural repair of bowing or shifting walls, which needs an engineer's plan, or finishing the basement afterward.
It is for homeowners with water in the basement after storms or snowmelt, buyers or sellers answering an inspection report, and anyone planning to finish a basement who wants it dry first. It is not for a single damp spot caused by a plumbing leak, which a plumber fixes.
Terms on a waterproofing estimate
- Cove joint
- The seam where the foundation wall meets the floor slab. Water under pressure often seeps in right along it.
- Hydrostatic pressure
- The push of water held in saturated soil against a wall or under a slab. It forces water through any weak point.
- Interior perimeter drain
- A perforated pipe set in stone just inside the footing, under the slab edge, that carries water to a sump.
- Sump basin
- A pit in the basement floor where drain water collects before the pump sends it outside and away.
- Battery backup pump
- A second pump that runs on a battery when the power fails or the main pump cannot keep up.
- Footing drain
- A drain pipe laid outside the foundation at footing level when the house was built. Many older ones clog.
- Crack injection
- Filling a foundation crack from inside with polyurethane or epoxy through small ports, sealing it through the wall.
- Grading
- The slope of the ground around the house. It should fall away from the foundation so rain drains outward.
Basement waterproofing questions
Eight questions about wet basements, with honest answers.
How much does basement waterproofing cost?
A targeted repair such as crack injection, downspout extensions or regrading costs $2,000 to $7,000. An interior drain with a sump and battery backup costs $9,000 to $18,000. Exterior excavation with a membrane runs $20,000 to $45,000 or more.
Is interior or exterior waterproofing better?
Exterior waterproofing stops water before it reaches the wall, but it means digging to the footing and restoring the yard. An interior drain manages water that gets in and costs far less. For most homes, interior drainage is the practical choice.
Why does my basement leak only when it rains hard?
Heavy rain overloads gutters and short downspouts and saturates the soil next to the wall. In most storm-only cases, extending downspouts, cleaning gutters and regrading the soil fix the problem without a drain system.
Can I fix a leaking foundation crack myself?
Surface patches from a hardware store rarely last, because water pushes through behind them. Injection fills the crack through the full wall thickness. A wide, stepped or shifting crack should be looked at by a professional, as it may be structural.
How long does basement waterproofing take?
A targeted repair takes one to two days. An interior drain and sump take two to four days for most basements. Exterior excavation takes one to two weeks, depending on depth, access and weather.
Do I need a sump pump battery backup?
If your basement is finished or stores anything valuable, yes. Storms that bring heavy rain also knock out power, which is exactly when the main pump stops. A backup pump runs for hours on a charged battery.
Will waterproofing get rid of the musty smell?
It removes the water that feeds it. A sealed sump lid, a membrane on the walls and a dehumidifier set near 50 percent humidity usually clear the smell within a few weeks, unless mold is growing in stored items or old finishes.
Should I waterproof before finishing my basement?
Yes, if the basement has ever taken water or shows white powder on the walls. Drywall, carpet and framing soak up water and grow mold within a season. Fixing the source first costs far less than tearing out a finished room later.
Basement waterproofing near you
Your remodeling address, within our service area.
Inspections and installs are handled by crews based in your area who know local soils and frost depth, under the license your state requires. The license list is on our licenses page.
- Maine
- New Hampshire
- Massachusetts
- Rhode Island
- Connecticut
- New York
- New Jersey
- Pennsylvania
- Delaware
- Maryland
- Virginia
- North Carolina
- South Carolina
- Georgia
- Florida
- Check your remodeling address
Same-week basement inspection
Send a photo of the water. We will find out where it comes from this week.
A waterproofing supervisor replies within 5 minutes during business hours, books the inspection within days and sends a written price for the smallest fix that works.