In Tempe, AZ, stucco is a reliable and popular exterior finish, offering durability and desert-ready aesthetics. But even in dry climates like the Valley, moisture can find its way behind stucco—especially during monsoon season or from faulty irrigation systems. Since stucco doesn’t always show surface signs of water damage, knowing how to check for hidden moisture is essential to prevent serious structural problems.
From staining and soft spots to high-tech detection tools, this guide walks you through the best ways to assess your stucco walls and catch issues early.
Key Takeaways
Hidden moisture behind stucco can cause mold, rot, and internal wall damage.
Signs include dark patches, bubbling, soft areas, and interior drywall issues.
Moisture meters and infrared cameras are effective tools for detection.
A professional inspection is recommended for accurate assessment and repair.
Why Moisture Can Be a Hidden Threat in Tempe
Despite Tempe’s arid environment, stucco is still vulnerable to moisture intrusion—especially after seasonal rains or sprinkler overspray. Water can seep in through:
Cracks or unsealed expansion joints
Poorly installed or aging windows and doors
Clogged or missing weep screeds
Stucco that’s installed below grade, trapping runoff
Once behind the surface, moisture can become trapped, particularly if the wall lacks proper drainage. That’s why it’s important to know how to assess for moisture without having to remove large sections of your stucco finish.
Warning Signs of Moisture Behind Stucco
Before using tools or calling a pro, look for these visual and physical signs:
Dark or discolored spots that don’t fade after drying
Blistering, bubbling, or flaking in the stucco finish
Soft or spongy areas when pressing the surface gently
Cracking near windows, doors, or wall joints
Interior drywall stains, peeling paint, or musty smells
If any of these are present, a deeper evaluation is recommended. Stucco Contractors Arizona can help determine if it’s superficial or a sign of deeper damage.
Tools to Detect Moisture Behind Stucco
1. Moisture Meter
Moisture meters are handheld devices that detect moisture within walls. Non-invasive models use electromagnetic signals, while pin-type models measure resistance between two probes inserted into the wall. Readings above 20% often indicate excessive moisture.
2. Infrared Thermal Camera
Thermal imaging detects temperature differences, often revealing cooler spots caused by trapped moisture. While not as precise as a moisture meter, it helps identify broad areas that may need further testing.
3. Probe Testing (For Professionals)
Some inspections involve drilling small holes and inserting moisture probes to test internal wall humidity. This method is more invasive but extremely accurate and is often used by licensed contractors like Stucco Contractors Arizona in Glendale during comprehensive moisture inspections.
What to Do If Moisture Is Detected
Pinpoint the Source: Common sources include roof runoff, faulty gutters, unsealed joints, or damaged weep screeds.
Remove Affected Stucco: Damaged areas must be carefully cut away to prevent spreading.
Repair the Substrate: Replace rotted wood, wet insulation, or rusted lath.
Restore and Seal: Apply a new stucco patch, match the existing finish, and seal properly. Consider a breathable fog coat to protect against future water intrusion.
Prevention Tips for Tempe Homeowners
Inspect Annually: Look for cracks, stains, or damage, especially around windows and eaves.
Maintain Weep Screeds: These metal strips near the base of stucco walls help drain water. Make sure they’re not clogged or buried.
Direct Sprinklers Away: Irrigation too close to stucco walls is a leading cause of hidden moisture in Tempe homes.
Apply Sealants Carefully: Use breathable products designed for stucco so moisture doesn’t get trapped behind the surface.
Trust Tempe’s Stucco Moisture Experts
Detecting moisture behind stucco early can save thousands in repairs and protect your home’s structure and air quality. Whether you’re experiencing subtle warning signs or want peace of mind after storm season, the team at Stucco Contractors Arizona is here to help.
We offer full moisture inspections, expert repairs, and preventive sealing tailored to Tempe’s unique climate. Contact us today for a comprehensive stucco checkup—and stay one step ahead of hidden water damage.