Cut out wet drywall

When you have a small water leak, you may not need to replace the whole sheet of drywall. In many cases, you can just cut out the drywall that got wet and replace only that section. Often this is a much cheaper solution.

What you need to watch out for is if mold or mildew has started to grow because of the dampness. It’s possible for mold and mildew to spread above the wet area of the drywall. All drywall with mold or mildew must be removed.

In this post we discuss how to cut and repair the wet drywall patch. We also discuss how to manage small mold or mildew issues the dampness may have caused.

Keep in mind, this do-it-yourself guide is only for small jobs only, inexperienced homeowners should seek professional help when dealing with major issues. Remember, mold and mildew can cause serious health issues, it’s not worth the risk.

What you need to cut out wet drywall

These are the tools and materials you will need to do the repair. I’ve also included a link at the bottom of this post to my video showing how to do the patching repair.

Tools and supplies

• Gloves
• Mask
• Protective eye wear
• Drywall saw
• Putty Knives
• Drop Cloth optional
• Drywall joint compound
• Self-adhesive drywall tape
• Sanding Blocks 4 assorted pack
• Sponge (optional)
• Drywall. Depending on the size of your patch most builder supply stores have small pieces of drywall available.

If dealing with mold or mildew you will also need:

• Diluted bleach cleaning solution – 1-2 tablespoons of bleach per cup of water
• Old rag cloth – to use with bleach solution
• Spray bottle – to use with bleach solution

Word of caution about mold

When removing mold/mildew proper protective equipment must be worn, including proper mask, gloves and eye wear.

If you intend to hire a contractor to remove mold and mildew, some states require contractors to meet special qualifications. Check with your state for any regulation requirements, before hiring a contractor.

When does drywall need to be replaced?

Unfortunately, drywall soaks up water and will become soaked in a short time. The quicker you manage the leak, the better chance you have of not getting mold or mildew.

However, sometimes small leaks are hidden. You may find a small patch of mold or mildew, or dark discoloration on a wall. This is likely a sign that water or moisture is getting behind the wall.

Anytime you have wet drywall that is soaked or has mold or mildew it must be removed and replaced.

How to cut out damaged drywall

Wet drywall, if left, can cause mold and mildew growth which is known to cause health issues.

Even if you don’t have evidence of mold on the wall, you should still wear all protective gear, as you don’t know what you will find as you cut.

Remove wet or moldy drywall by cutting out all wet or damaged sections. You can use a drywall saw.

Start just outside of the wet drywall area. Cut until you reach one of the 2×4 beams. Do not cut the beam but do cut the drywall out to the half-way mark of the beam. This will give you a place to attach the new drywall patch.

In some situations, you will not be able to cut to a beam. When this happens, building supply stores sell metal brackets of different configurations so you can mount an additional 2×4 wood beam.

Working with mold

Handle with care. Place all moldy pieces in a trash bag right away and close the bag slowly. It’s very important you do not cause the mold spores to become airborne.

Remove all wet drywall and insulation. If you have mold or mildew on the studs, you’ll need to kill the mold with a mold killer or diluted bleach solution.

You can find commercial products to kill mold and mildew at most janitorial stores. There are also home remedies you can use. On hard surfaces (non-porous) you can use non-ammonia detergent with a brush or rag as needed. For hard-to-reach areas inside the wall you can spray a 10% bleach solution.

You can mix the solution in a spray bottle to mist any areas out of reach of your cloth. Be sure to wipe down surfaces completely. Also, protect your carpet or flooring by pulling it back or using heavy drop cloths. Bleach will cause discoloration.

Allow the inside of the wall to dry completely before moving to the next step. This could take a few days, especially if there was lots of moisture.

When you are ready to patch the wall

After you have removed the wet drywall and fixed the leak that caused the issue in the first place, you’ll need to repair the hole.

Start by measuring the hole. Next, cut your drywall patch just a little larger. Place the natural straight edge of the drywall against the halfway mark of the stud. Hold the patch firmly in place.

The rest of the drywall patch should slightly overlap the existing drywall. Trace around the patch on the wall. Then remove the patch and trim the wall to match your patch. Your patch should now fit snug into the hole in the wall.

Installing the drywall patch

Attach the drywall to the beams by using drywall screws, about 5-inches apart. Do not sink the screws in too far, they should just barely sink into the wall. In other words, do not break through the finish of the drywall.

Apply self-adhesive drywall tape over the joints at the cut, overlapping evenly on either side.

Apply drywall paste and leave for 24 hours before sanding or wet sponging. If drywall paste shrinks, just re-apply another coat after 24 hours drying time. You are likely to need at least two coats.

When you are happy with the finish, paint the wall.

As it’s easier to show you, I have put together a video on repairing small areas of drywall damage. This video shows filling small dents with the paste. You can apply the same method with the drywall paste over the drywall tape.

At minute 2.45 I specifically start talking about matching the wall texture and at 3.25 I demonstrate the technique.

Please visit my YouTube Channel and consider subscribing if you found this information useful.

Thanks for checking out this post, hope it was of help to you. Watch for more drywall posts coming soon.

Where to find more information.

• FEMA also has their home product recommendations for treating mold in their Online book called Dealing with Mold & Mildew in your Flood Damaged Home.