The short answer
Visual Clues
Start by examining the corner closely in good light. Water stains often appear as yellow, brown, or dark rings that spread outward from the corner. Look for paint that is bubbling, cracking, or peeling, which can indicate moisture behind the surface. Also check for drywall tape that is lifting or separating at the corner bead.
Discoloration may be subtle at first, so compare the corner to the rest of the wall. If you see a slight change in shade or a damp-looking patch, that is a warning sign. In humid climates like Rowlett's, moisture can linger and worsen, so catching it early matters.
Touch and Smell
Run your hand slowly along the corner and the adjacent wall surfaces. Damp or soft drywall feels different from dry, firm drywall. Press gently with your fingers; if the material gives way or crumbles, water damage is likely. Also feel for cold spots, which can signal moisture behind the surface.
Your nose is a useful tool. A musty or earthy smell near a corner often means mold or mildew is growing, which happens when moisture sits for a while. If you notice a smell, check the area for visible mold spots, which may be black, green, or white patches.
- Soft spots that depress under light pressure
- Drywall that crumbles or flakes away
- Musty odor that worsens near the corner
- Cold or clammy feeling on the wall surface
- Visible mold or mildew patches
Use a Moisture Meter
A moisture meter is a handheld tool that gives a numerical reading of moisture content in drywall. You can buy one at a hardware store or borrow from a tool library. Press the pins or the non-invasive sensor against the corner and compare the reading to a dry area of the same wall.
Readings above 15 percent usually indicate moisture problems, but follow the meter's instructions for interpretation. If you do not have a meter, you can use the touch test, but a meter is more precise. For a thorough check, a water damage inspection can map out the extent of the issue.
Check the Source
Water in a corner often comes from a leak above, such as a roof, gutter, or pipe. Look for signs of stains on the ceiling near the corner or along the top edge of the wall. Also check the exterior of the house for damaged siding or gaps around windows and doors that could let water in.
If the corner is on an exterior wall, consider the foundation. Poor drainage or a cracked foundation can allow groundwater to seep in. In some cases, the leak comes from a plumbing line inside the wall. If you cannot find the source, a professional inspection can help identify it.
- Stains on the ceiling near the corner
- Damaged roof shingles or flashing above the wall
- Clogged or leaking gutters and downspouts
- Cracked or missing caulk around windows or doors
- Gaps in exterior siding or trim
- Poor soil grading that directs water toward the foundation
What to Do Next
If you find water damage, act quickly to limit the spread. Move furniture away from the area and place a bucket under any active drip. Dry the surface with fans and dehumidifiers if possible, but do not try to dry drywall that is saturated; it may need to be cut out. Turn off electricity to the room if water is near outlets or light fixtures.
For significant damage, contact local water damage pros for an assessment. They can extract standing water and evaluate the drywall for replacement. If the corner is load-bearing or near electrical wiring, do not attempt repairs yourself; leave that to a professional. Your insurance policy may cover the damage, depending on the cause and your coverage.
Water damage does not wait
Phones are answered 24/7 for Rowlett and nearby communities.
Call Now (214) 730-5993Frequently asked questions
Can I dry out wet drywall myself?
Small damp spots may dry with fans and good airflow, but saturated drywall often loses its strength and may crumble. If the drywall is soft or sagging, it likely needs replacement. For large areas, water extraction and drying are right for the pros. Policies vary, and your insurer decides what is covered.
How do I know if mold is growing in the corner?
Look for black, green, or white spots and a musty smell. Mold can appear within 24 to 48 hours of moisture. If you see mold, avoid touching it and consider hiring a mold professional to assess and remove it safely.
What should I do if I find a leak behind the wall?
Turn off the water supply if you can identify the pipe, and shut off electricity to the area if needed. Call a plumber to fix the leak. Then have the drywall inspected for damage; the pros can determine what needs to be cut out and replaced.