Encountering metal behind drywall typically means you’ve hit a stud guard (a metal plate protecting wires and pipes), a metal wall stud, a heating/AC duct, or mesh/lath from an older plaster wall.
If you hit or see metal behind your drywall, it is usually a structural component, a safety feature, or a utility run.
To tell if mold is behind drywall, look for physical wall damage (peeling paint, bulging, or stains) and notice if there is a persistent musty odor. For an exact check, use a moisture meter or a borescope camera to peer inside without tearing down the wall.
Common Signs of a Bad Drywall Job
Over time, breathing the dust from drywall joint compounds may cause persistent throat and airway irritation, coughing, phlegm production, and breathing difficulties similar to asthma.
Some people add a small amount of dish soap to drywall mud to reduce surface tension, which helps release air bubbles and create a smoother, more even finish, especially when applying the final "skim coat"; however, this practice is not recommended by professionals as it can potentially weaken the adhesion of the mud ...
Mold toxicity (mycotoxin illness) happens when prolonged exposure to mold spores triggers chronic inflammation and immune system activation. Symptoms are often subtle and mimic other illnesses, but common red flags include persistent allergy-like reactions, chronic fatigue, unexplained brain fog, recurring headaches, and respiratory or digestive distress.
Early stage mold on walls often appears as faint cloudy discolorations, tiny black dots, or peeling paint. The most reliable indicators are a lingering musty odor and nearby moisture from leaks or high humidity. Catching it now makes it much easier to treat and prevents structural damage.
In A Nutshell: Misconceptions About Mold
Your home can be 100% mold-free: No, there are always mold spores in the air. Anyone can effectively remove mold: No, you need professional services for that.
To find metal studs behind drywall, use powerful neodymium magnets to locate the steel drywall screws, or use an electronic stud finder with a dedicated metal-scanning mode. Metal studs are typically spaced 16 to 24 inches apart, and most electrical outlets will be directly attached to one.
Yes, your phone can function as a stud finder, but with a catch: it uses your phone's built-in magnetometer (which powers the compass) to detect the metal screws or nails hidden in your drywall, rather than the wood itself.
Drywall is considered "bad" or compromised when it sustains severe moisture damage, loses its structural integrity, or becomes a host for mold. The fastest way to check your drywall is by inspecting the surface for visual clues and performing simple tactile tests.
Since you know it's drywall use a magnetic stud finder. They catch on the screws so you can be certain of there being a stud.
These can be thin sheets of galvanized steel or aluminum behind the drywall. If your bathroom was originally plaster, there might be expanded metal lath behind the drywall. This can be drilled through, but it can dull regular drill bits quickly.
To locate a stud, users move the magnet across the wall until they detect a noticeable pull. Magnetic stud finders operate on the assumption that fasteners are driven into the center of studs, although this is not always accurate. Therefore, users often confirm stud spacing by locating multiple fasteners.
Yes, it is very bad to sleep in a room with mold. Because your body rests for 6–8 hours, you are continuously breathing in microscopic spores. This can trigger immune responses, disrupt your sleep cycle, and cause long-term respiratory issues.
Additionally, spraying a solution of equal parts vinegar and water or a diluted hydrogen peroxide solution into the air can help to kill airborne mold spores.
Mold exposure typically causes allergy-like symptoms. The best way to know if mold is making you sick is by observing where and when your symptoms occur. If you consistently feel unwell indoors (especially after a water leak) and your symptoms improve when you leave the home, mold is likely the trigger.
To test yourself for mold exposure, you can use specialized at-home urine mycotoxin kits or consult a doctor for allergy tests (blood tests or skin pricks). If you suspect your home or workspace is the source of the mold, you can use DIY environmental sampling kits.
According to the CDC, people usually experience their first symptoms within 2 to 9 hours of their first exposure. On the other hand, some people could go for weeks or months before feeling sick if their exposure is limited enough. This is why it is also important to check damp, dark areas of your home for mold.
Leaving mold in your house allows it to aggressively spread, slowly rotting wood, drywall, and carpets. Prolonged exposure releases airborne spores and mycotoxins, which can trigger respiratory distress, asthma attacks, chronic fatigue, and—in severe cases or vulnerable individuals—serious fungal infections.
Effects When Inhaled
Drywall dust allergy symptoms include: Runny nose. Coughing. Sinus congestion/infection.
Two common mistakes made during drywalling are improper joint compound application (such as applying it too thickly or not feathering the edges), and failing to stagger the seams across different studs, which weakens the wall and increases the risk of cracking.
An orbital sander is an option for a large drywall project. This tool is lightweight and can perform the task in less time, but as a power tool it must be used carefully to avoid damaging the drywall surface. Use fine grit sandpaper, between 150 and 180 grit, to achieve the desired results.