Moldy Finished Basement Repair in Pembroke, NH

Friday, February 13th, 2026 by Marcus Girard

Challenge

In Pembroke, NH, a homeowner faced significant mold and wood rot in her finished basement due to a failing sump pump. As seen in the photos, moisture damage required the removal of affected wall sections and flooring. Without a reliable waterproofing system in place, long-term water issues like these often lead to costly structural and air‑quality problems. Left unresolved, moisture can continue to drive mold growth, musty odors, and deterioration of building materials—putting both comfort and home value at risk.

This homeowner had lived in the home for more than 40 years, having noticed water problems since she was a teenager. Her goal was not only to restore the space but to protect her father’s legacy by finally resolving the issue permanently.

Our process began with a Customer Care Specialist coordinating a convenient inspection. Our System Design Specialist Chuck B. then performed a detailed evaluation to identify the causes of the sump pump failure, trace moisture pathways, and design a durable, code‑compliant solution that ensures long‑term protection and peace of mind. Water was entering the basement through the slab-floor interface and cold joints, allowing hydrostatic pressure to force moisture up through vulnerabilities in the concrete. During peak events, as much as six inches of standing water could accumulate in the space at one time.

The resulting system solution included:

127 ft of WaterGuard® — Interior perimeter subfloor drainage
17 ft of TrenchDrain™ — Surface drainage at key water entry points
1 TripleSafe™ Sump Pump System — Primary + secondary + battery backup
2 IceGuard® — Discharge line freeze/obstruction protection
25 ft of exterior discharge line — Safe routing of pumped water
1 SaniDry™ XP — High‑capacity basement dehumidification

Solution

On the day of installation, the foreman contacted the homeowner upon departing the shop to confirm arrival time. After greeting the homeowner and reviewing expectations during a walkthrough, the crew began by removing a narrow strip of concrete along the full interior perimeter of the basement. This created the trench needed to establish the WaterGuard® subfloor drainage system.

WaterGuard® Installation — Subfloor Perimeter Drainage

WaterGuard® was installed at footing level, beneath the slab, where it continuously intercepts groundwater and wall seepage before moisture can reach the finished space. The team jackhammered and removed the slab strip, excavated the trench, placed a clean bed of crushed stone for stable support and free drainage, and set the WaterGuard® channel tight to the wall/sill interface. Each run was carefully pitched to direct captured water toward the sump basin, ensuring efficient, reliable flow under normal and peak conditions.

Integrating TrenchDrain™ Around Fixed Utilities

In sections where trenching at the footing was not feasible—most notably near an immovable oil tank—the crew integrated TrenchDrain™, a grated, surface‑level drainage component. This allows surface and incidental water in otherwise inaccessible areas to be captured effectively. By tying TrenchDrain™ directly into the WaterGuard® network, the system remains continuous and hydraulically unified, so all collected water is conveyed to the sump without interruption.

TripleSafe™ Sump Pump System — Redundant Pumping for All Conditions

The TripleSafe™ Sump Pump System was then installed to provide three layers of protection:

A primary pump for everyday groundwater removal
A high‑capacity secondary pump that engages during heavy inflows
A battery‑powered backup pump that operates during power outages or component failures

The sump liner was set in a properly excavated pit, sealed to limit humidity transfer, and connected to the interior drainage system so all intercepted water is managed in one controlled location. For homeowners planning to refinish their basement, this triple‑redundant configuration delivers exceptional peace of mind by maintaining dry conditions through a broad range of operating scenarios.

Discharge Line, IceGuard®, and Bubbler Termination

Collected water is expelled via a dedicated discharge line routed away from the foundation. To safeguard this pathway, an IceGuard® fitting was installed on the exterior section of the discharge. IceGuard® acts as a failsafe: if the line freezes or becomes clogged, its engineered ports automatically vent water outside—preventing backups and keeping the basement dry even in freezing conditions. The discharge line was extended to a properly graded location and connected to a bubbler pot at grade. Once the connection was made, the line was fully buried below the lawn, preserving curb appeal while dispersing water safely into the surrounding soil.

SaniDry™ XP — Humidity Control and Air Quality

To address previous mold concerns and maintain healthy indoor conditions, a SaniDry™ XP was installed. This high‑capacity dehumidification system continuously filters and dries the air, keeping relative humidity below mold‑growth thresholds. By protecting building materials from prolonged moisture exposure and reducing musty odors, the SaniDry™ XP enhances comfort in the basement and benefits the overall air quality throughout the home.

Commissioning, Finish, and Homeowner Walkthrough

Before closing the system, the crew performed a thorough water test to verify proper flow through WaterGuard® and TrenchDrain™, confirm airtight sump connections, and validate discharge performance through IceGuard® and the bubbler termination. After re‑pouring concrete over the perimeter trench for a clean, flush finish, the team completed a final cleanup and walkthrough with the homeowner—reviewing system operation, maintenance best practices, and what to expect as they move forward with refinishing.

With a continuous drainage network, redundant pumping, protected discharge, and whole‑space humidity control, the basement is now prepared for refinishing and safeguarded against future water intrusion—delivering long‑term protection and peace of mind.