Perimeter channel systems that capture and redirect water at the point of entry, protecting your basement without exterior excavation or landscape disruption.
The practical approach when exterior excavation is not feasible or needed.
All work is performed from inside the structure, preserving driveways, gardens, and exterior features.
Rather than waiting for water to accumulate, channel systems intercept it at the point of entry for immediate collection and removal.
Interior drainage is not weather-dependent. Installation can proceed in winter months when exterior excavation and membrane work are not feasible in Greenwich, KS conditions.
Properly designed interior channel systems use gravity to route water to the sump pit without mechanical assistance, supplemented by the pump only when pit level reaches the activation threshold.
An interior drainage system addresses basement moisture by capturing and redirecting groundwater after it has entered the building envelope at the floor-wall joint or through weep holes at the base of the foundation wall. This differs fundamentally from exterior waterproofing, which prevents water from reaching the wall surface. Interior drainage accepts that water will enter under certain pressure conditions and provides a managed pathway for that water to reach a collection point without spreading across the basement floor or damaging finished materials. For Greenwich homes where exterior excavation is impractical, cost-prohibitive, or where the moisture entry is concentrated at the perimeter footing level, interior drainage is the technically appropriate solution.
Once the trench is cut, the system design determines how effectively water is captured. Basic systems use a simple gravel bed with a perforated pipe to collect and route water. More advanced channel profiles, often called proprietary drainage channel systems, incorporate a raised profile that sits slightly above the footing and captures not just floor-joint seepage but also water migrating down the wall face. A wall flange component extends up behind any baseboard or framing material to intercept water running down the wall before it reaches the floor level. This wall flange detail is important in situations where the moisture entry is not strictly at the floor joint but extends up the lower wall section, which is common in Greenwich homes with older block or stone foundations where the mortar has deteriorated.
The sump pit integration is the component that makes an interior drainage system fully functional. The channel system routes water to the pit, and the pump removes it from the pit before it overflows. Pit location is determined by the channel routing geometry, existing pit locations if present, and access to a discharge route. In some Greenwich homes where the basement has been partially finished, the channel must be routed around finished walls and mechanicals to reach an optimal pit location. These routing decisions are made during the assessment and documented in the installation plan. The pit itself is sized to provide adequate storage volume for the expected inflow rate, ensuring the pump is not short-cycling and the system has adequate buffer during peak inflow events.
The honest tradeoffs of interior drainage versus exterior waterproofing are something we address directly during every assessment in Greenwich. Interior drainage is less invasive, faster to install, unaffected by seasonal weather constraints, and generally less expensive per linear foot than exterior excavation and membrane work. However, it does not eliminate the moisture that is contacting the wall surface; it captures and removes water after it enters the building envelope. For homeowners whose primary concern is protecting finished basement space from water accumulation on the floor, interior drainage addresses that objective effectively. For homeowners concerned about long-term wall deterioration from moisture contact, or whose walls show active spalling and efflorescence from chronic wet conditions, the exterior treatment addresses the wall moisture directly. When both conditions are present in the same structure, we discuss a combined approach that treats both the wall surface and manages floor-level seepage.
From perimeter channel installation to sump integration and annual service, a complete interior drainage solution.
Saw-cut perimeter channel around the full basement footprint, with gravel bed, drainage channel, and sump pit connection. Complete protection for all four walls in one installation.
Learn moreWe document which walls show active moisture evidence and design targeted channel runs that address the documented entry points without over-specifying scope.
Get an assessmentThe wall flange component extends the drainage channel up behind the base of the wall to capture moisture migrating down the wall face before it reaches the floor.
Ask about wall flangesPit location decisions consider channel slope, discharge routing, basement layout, and finished area constraints. We document the reasoning for every pit placement recommendation.
Plan your pit locationA drainage system that was properly installed years ago but has degraded can often be restored through cleaning and targeted component replacement at far less cost than a full reinstallation.
Schedule an inspectionExpansion scopes are common when a homeowner finishes additional basement space and discovers that the existing partial channel does not cover the newly used area.
Expand your systemA methodical process that produces a drainage system built to perform for decades.
The assessment produces a written condition report that forms the basis for every specification decision in the installation plan. No work is designed without this foundation.
Cut dimensions are verified before the gravel bed is placed to confirm the channel profile will sit at the correct elevation relative to the footing.
Gravel bed placement, drainage channel positioning, wall flange installation where specified, and sump pit connection are completed in sequence. Channel slope is verified with a level to confirm gravity-assisted flow toward the pit throughout the entire system.
New concrete is poured over the channel system, restoring the floor surface and permanently enclosing the drainage installation. After cure, the full system is tested by introducing water at multiple points along the channel and verifying flow to the sump pit and pump activation.
The results our Greenwich clients experience speak clearly.
The assessment was thorough and they explained exactly which wall sections were causing the problem. The installation took one day and the crew cleaned up completely before leaving. The following spring, which was wet, produced zero water on the basement floor for the first time in seven years.
Our older block foundation was not a candidate for exterior work without major landscaping disruption. The interior channel system gave us the protection we needed without touching the exterior at all. The wall flange detail they added captured the seepage that was running down the bottom block course, which was the main issue.
We had the system installed in November, which would have been impossible with exterior work given the ground conditions that time of year. The interior installation was unaffected by weather and completed in a single day. The system handled a major rain event the following week perfectly.
What you need to know to make a confident decision about interior drainage.
The installation begins with saw-cutting the basement floor slab along the planned channel route, typically four to six inches from the foundation wall. The cut follows the interior perimeter of the basement and terminates at the sump pit location. Concrete is removed and the subbase is excavated to reach the footing level, then a gravel bed is placed, the drainage channel profile is set to slope toward the pit, and the wall flange is installed where specified. New concrete is poured to cap the system and restore the floor surface. Most residential installations in Greenwich are completed in a single working day for standard perimeter configurations.
The functional lifespan of an interior drainage system is largely determined by the durability of the channel material and the ongoing performance of the sump pump that removes the collected water. The channel installation itself is a permanent modification to the basement floor structure. The pump requires regular testing and periodic replacement, typically every 7 to 10 years. An interior drainage system that is properly maintained in a Greenwich home can provide effective moisture management indefinitely.
Interior drainage typically costs less per linear foot than exterior excavation and membrane waterproofing, primarily because the excavation equipment, soil management, and backfill work associated with exterior projects add significant cost to that scope. For most standard residential configurations in Greenwich, interior drainage is a more budget-accessible solution. However, cost comparison alone should not drive the decision; the correct approach depends on the moisture entry mechanism present in your specific basement. Installing interior drainage to address a problem that is fundamentally an exterior membrane failure will provide comfort improvement but will not stop ongoing wall contact moisture, which continues to deteriorate the wall material.
Standard full perimeter interior drainage installation for a typical single-story Greenwich basement is completed in one working day. Partial perimeter systems on one or two walls are typically finished in half a day. Basements with complex layouts, finished areas requiring careful routing, or multiple existing pipe penetrations crossing the channel path may extend the installation to a second day. We provide an accurate time estimate after the assessment so homeowners can plan for the dust and noise associated with saw-cutting, which is the most disruptive phase of the installation.
We offer annual drainage system inspection as part of our maintenance program in Greenwich, which covers both the channel system condition and the sump pump. Catching issues like partial blockages or pump wear before they cause failure during a high-inflow event is the purpose of the inspection. Most homeowners find that scheduled annual service eliminates the reactive emergency calls that occur when a problem is discovered during a storm.
Many Greenwich homeowners choose to address interior drainage before finishing a basement, which eliminates the need to remove and restore finished materials. However, we complete drainage installations in finished spaces regularly and coordinate the scope carefully to minimize disruption. The finished floor and base materials removed during installation can typically be sourced and replaced within the standard timeline of a moisture remediation project.
No excavation. No landscape disruption. Just a properly installed channel system that manages water at the point of entry, year after year.
Call +1-866-476-1348 for Assessment