How to Spot, Prevent, and Help Repair Drywall Water Damage

You spot a yellowish water stain growing on a wall in your home. Never a good sign. Behind that wall, something’s leaking. Once you find, and stop, the cause of the leak, it’s time to consider the state of your drywall. 

Drywall is the flat panel beneath the paint or wallpaper of your walls. It’s made of mostly gypsum plaster pressed between two sheets of thick paper. While it’s usually very sturdy, drywall soaks up moisture fast. When drywall and water damage collide, it can lead to severe issues like structural damage and mold. 

Key Takeaways

• Drywall and water damage don’t mix. Once moisture gets into your walls, drywall can weaken, swell, or start growing mold in a matter of days.
• Signs that you might have water behind your walls are stains, sagging, and a soft or bubbling texture.
• Some of the most common causes of water damage behind walls are leaky pipes, roof damage, and appliance overflows.
• You may be able to dry and patch small, isolated water stains on your walls. However, larger or moldy wet areas usually require full replacement.
• If you want to avoid future drywall repair, try to catch leaks early, keep your gutters clean, and watch the humidity levels in your home. 
• Take a look at SERVPRO’s water damage resources to get up to speed if you’ve had a major leak in your home. 

What Happens When Drywall Gets Wet?

Drywall does not stand up to water damage very well. Gypsum is a soft mineral that easily absorbs water. As soon as the drywall gets wet, the paper backing starts to break down, and the material loses its structural integrity. 

The amount of moisture that soaks into your drywall determines just how damaged it can be. For example, spilling a bottle of water against your wall isn’t going to do much harm, but a bathroom flooded by a backed-up toilet can cause structural damage to the joints that hold up drywall pieces. It may also lead to the wooden structure deteriorating. Even without direct contact with Sheetrock, water damage tends to breed mold spores. If you leave your wall to dry independently, these mold spores can rot and decay, releasing foul odors. 

How to Spot Drywall Water Damage

Sometimes water-damaged drywall is obvious, but other times it hides until the problem grows so big you can’t ignore it. The earlier you can catch water damage, the smaller the repair—and the lower the bill are likely to be. 

So, here’s what to look, feel, and listen for if you suspect water behind your walls. (Note: the location and pattern often point to the source of the leak.) 

Visual Signs

Keep your eyes open for the following signs of water damage in your walls:

• Yellow, brown, or copper-colored stains
• Paint that’s peeling, bubbling, or cracking
• Wallpaper lifting away from the wall’s surface
• A patch of wall that looks darker or duller than the rest
• Visible mold, which can appear as black, green, or white spots

Structural Signs

Sometimes you have to touch a wall to figure out what’s really going on. Press gently on any suspicious areas and check for:

• Soft or spongy spots that give under light pressure
• Sagging or bulging sections
• Cracks forming near the damaged area
• Nails or screws popping out as the drywall shifts

Smell and Sound

If you’re not able to see or feel water damage in your drywall, your first clue might be a musty odor. That smell is a common sign of mold growing behind the wall. Tap on the wall. If you hear a dull, thud-like sound compared to the surrounding area, that could mean that water has settled behind your wall’s surface. 

How to Test for Hidden Moisture

Still not if you have drywall damage? Try the aluminum foil test. Tape a square of aluminum foil over the suspected area of water damage. After a day or two, check for moisture on either side of the foil. If you find beads of water on the side of the foil facing the wall, the moisture likely came from inside the wall. If the water is on the outside of the foil (the side facing the room), it’s likely condensation.

Of course, there’s a surer way to check for water-damaged drywall. Hire a professional water remediation team to assess your walls using professional moisture mapping. 

What Causes Drywall to Get Wet?

Your walls can be at risk of water damage from a variety of sources, from a broken window during heavy rain to a leaky pipe. Here are some things to look out for:

• Leaks and malfunctions in the kitchen
• Leaks and malfunctions in the bathroom   
• Plumbing failures   
• Malfunctioning HVAC   
• Cluttered HVAC vents
• Damaged roofing 
• Damaged windows   
• Natural disasters with heavy rainfall  

Does Wet Drywall Need to Be Repaired or Replaced?

Did your walls get more than a light soaking? The good news is you don’t need to automatically toss all your water-damaged drywall directly into the dumpster. Whether you can save your drywall or need to tear it out depends on a variety of factors. 

When You Can Likely Repair Your Drywall

• The drywall was only briefly damp, like from a small splash or short-lived leak
• It still feels firm to the touch, with no soft or spongy spots
• There’s no sign of mold, warping, or a lingering musty smell
• The water was clean, not from a sewage backup or flood

When You’ll Likely Need to Replace Your Drywall

• The drywall feels soft, swollen, or crumbles when you touch it
• Mold has started to grow
• The wall was soaked for more than 24 hours
• The water came from a contaminated source, like sewage or floodwater

When in doubt, call in a professional to take a look. Even if your drywall feels and looks fine on the surface, that doesn’t mean it isn’t compromised underneath. 

How to Help Repair Drywall Water Damage

If you’re able to rescue your drywall after a water incident, that’s great! Drywall and water damage don’t always mean a total loss. Assuming you’ve stopped the source of the leak (which you absolutely must do before starting any repairs), make sure your drywall is completely dry before you begin your work. 

How to Repair Small Drywall Damage Yourself

• With a pencil, outline the portion of drywall damaged by water that needs to be removed. It’s best to go a little bigger than needed when removing the damaged section of drywall.
• If the portion of drywall removed is smaller than four inches, you can use a drywall patch. If the removed portion is larger than four inches, you’ll need to cut a new piece of drywall to match your dimensions. Use the damaged drywall as a template, if possible, or use a measuring tape to get the proper dimensions. 
• Install a 1 x 2 furring strip behind the drywall to support the new wall section.   
• Insert the new drywall patch/drywall into your precut section. Using a drill, insert screws one inch from the perimeter of the drywall into the 1 x 2 furring strip behind the drywall.   
• Apply drywall tape to the edges around the new patch/drywall. Smooth a thin compound layer over the drywall/patch with a putty knife.  
• Paint your repaired drywall to match the rest of the wall.

What a Professional Drywall Repair Looks Like

• You may be able to repair small, isolated spots of damaged drywall on your own but call a professional for larger or more complicated damage.
• A professional water remediation team will start the repair process by confirming that your wall is fully dry and free of any hidden moisture. If they find lingering moisture, they’ll use industrial drying equipment to get rid of excess water. 
• From there, they’ll cut away damaged drywall, replace it with matched drywall, and finish the surface so the repairs blend seamlessly with your existing wall.
• If your drywall absorbed a lot of water damage, your team may also perform structural repairs, like fixing the framing behind the wall.  

How to Prevent Drywall Water Damage

It’s impossible to prepare for every situation, but there are steps you can take to help limit water damage to your walls and other parts of your home. These can help save you money, along with hours of stress and headaches.     

• Hire a roofing inspector to assess your roof for any cracks or signs of damage that might let water enter from heavy rain or a natural disaster.   
• Inspect your gutters for clogs (or call a gutter inspector). Make sure any blockages are removed that could back up rainwater onto your roof.  
• Have your HVAC system inspected for malfunctions, and your duct vents inspected for clogs or rips.   
• Check and properly caulk doors and windows to help prevent water seepage.
• Keep indoor humidity levels between 30 and 50 percent to prevent condensation from burrowing into your walls. Use a dehumidifier if needed, especially in bathrooms and kitchens.
• Use moisture-resistant drywall in the areas of your home prone to dampness, like bathrooms and basements.
• Know where your home’s main water shut-off valve is, so you can act fast in an emergency.   

SERVPRO Provides Water Damage Repair Services and More

When it comes to drywall and water damage, let SERVPRO do the heavy lifting for you. Our team will extract the remaining water, dry your walls and other structures, check for hidden moisture, and treat any mold that might be trying to invade your home. After all that, it’ll be time to perform the cosmetic repairs to return your walls to the best condition. 

SERVPRO technicians are available 24/7 to handle any water-related emergency. Find your local SERVPRO team today. 

FAQs

How Long Can Drywall Be Wet?

Drywall can typically only handle brief exposure to water. Try to dry your walls within 24 to 48 hours. Beyond that window, mold can begin to grow, and the drywall starts to weaken, swell, or lose its shape. 

How Can You Tell if Wet Drywall Needs to Be Replaced?

You should usually replace your drywall if it feels soft or spongy or is visibly crumbling. Other signs that you won’t be able to save your drywall are sagging, visible mold, warping, or a musty smell that won’t go away. If the water damage came from contaminated water, you’ll need to replace your drywall. 

What Happens if Drywall Gets Wet?

Drywall absorbs water quickly because it’s made of gypsum and paper. Once wet, it can swell, soften, or lose its structural integrity. If you don’t dry the water quickly, mold can start to grow within a day or two. 

Can Sheetrock Get Wet?

Sheetrock is a brand name for standard drywall. If possible, you should try not to let it get wet. It reacts to water the same way as any type of drywall. That is, it will easily absorb the water, which can quickly lead to damage and mold growth.