What Are Signs of a Slow Leak Inside Walls?

A persistent musty or earthy odor is often the first clue of a slow leak. This smell is caused by mold or mildew growing on damp wall materials like wood and drywall. The odor may be strongest near the affected wall, especially during humid weather. Even if you see no water, a new, unexplained smell inside your home warrants investigation. The smell can linger in carpets or furniture near the wall as well.

A hidden leak often reveals itself through your water usage. Turn off all water fixtures and appliances inside and outside your home. Then, check your water meter. If the dial is still moving, you likely have a leak. Compare your current water bill to past bills; a steady, unexplained increase points to a continuous water loss, possibly inside a wall. Some modern meters have a leak indicator, a small triangle or gear that spins with any water flow, which you can also watch for movement.

Local water damage pros use specialized tools like moisture meters and thermal imaging cameras to find the exact leak location and measure moisture levels inside walls without causing unnecessary damage. They then create a focused drying plan, which may involve removing a small section of drywall to circulate air and using dehumidifiers. This controlled approach helps prevent mold and saves undamaged materials. They also check adjacent rooms and materials, like insulation, that may have absorbed moisture from the leak.