How to Identify Leaking Pipes In a Wall

Moistness and discoloration indicate water damage and concealed leaks.

Leaking pipes in walls require immediate attention; concealed leaks cause structural damage, lead to mold and reduce indoor air quality. If your water bill or water meter reading shows an unusual increase in water usage, you might have a hidden leak or broken pipe. Although most leak indicators are visual, they aren't always in plain sight. To identify leaks before they lead to serious damage, learn both what to look for and where to search.

Things You'll Need

• Disposable gloves
• Flashlight

Instructions

1. Inspect exposed wall surfaces for discoloration. The types of discoloration that indicate concealed water leaks include stains with distinct borders and black or gray streaks. Search the wall's entire surface; plumbing pipe joints, called fittings, often occur at corners or the borders between walls and ceilings or floors.

2. Put on disposable gloves before you touch discolored surfaces; contact with some types of mold is harmful. If you decide to touch a surface to determine dampness, touch the wall with a glove and inspect the glove for a glistening that indicates moisture or rub the fingers of the gloves together to feel for slickness.

3. Inspect walls for mold or mildew, which often indicate hidden leaks. Look for the splotches or spots that indicate mold or mildew growth; mold and mildew often appear as black, white, orange or green spots. Look for discoloration and mold inside utility closets and utility access doors, particularly closets and doors that hold water shut-off valves or water heaters. Search within both upper and base cabinets. Use a flashlight to illuminate dark areas.

4. Smell the air for a stale or damp odor. Musty smells often indicate mold or mildew, which might stem from a concealed pipe leak.

5. Check walls for bulges and dips. Inspect the walls visually or by running your hand across the surface. Bulges and dips sometimes indicate that a broken pipe is causing wooden framing to swell or warp. Look for cracking or peeling paint; moisture that passes through wall coverings sometimes causes paint to blister.

6. Tap wall and door trim, such as casing, baseboard and crown molding. A hollow sound indicates rot and a possible pipe leak. Listen for noises that indicate pipe leaks, such as hissing, dripping or gushing. Small pipe punctures often hiss like a deflating balloon.

Tips & Warnings

• Open drywall walls with a drywall knife or a utility knife.

• After repairing leaks, use a dehumidifier to completely remove moisture from the wall cavity and surrounding areas.

References

• Oregon State University: Home Moisture Problems
• University of New Mexico: Mold Remediation for Tenants and Landlords
• Nipomo Community Services District: What Is Leak Detection?
• Centers for Disease Control and Prevention: Protect Yourself from Mold