How to Remove Mold from Drywall

Remove mold from drywall
Black mold on drywall

Apart from being an obvious health hazard, mold on drywall is unsightly and can either indicate an indoor water leak or humidity problem. Here we will discuss methods of removing mold from both finished and unfinished drywall. However, before any of these steps can be taken the cause of the problem needs to be addressed.

Table of Contents
  • How to remove mold from finished drywall
  • How to remove mold from unfinished drywall

Before attempting to remove mold from your drywall it would be best to find out the cause. The usual causes are high indoor humidity levels which can easily be resolved. And the second cause is usually a leaky pipe, most often behind the wall or above in the ceiling.

After first taking care of these problems can you safely start the mold removal process without having to worry whether or not the mold infestation will return.

How to remove mold from finished drywall

The process behind removing mold from finished (painted) drywall is quick and easy compared to unfinished drywall. The coat of paint seals off all pores, therefore any mold on your wall is merely surface mold and can easily come off. The only choice you really have to make in this regard is what type of cleaning detergent to use. Here you will find a list of effective cleaning solutions but in this example we will use baking soda.

Step 1:  Prepare your cleaning solution

As mentioned, we will be using baking soda in this example. Simply mix one part baking soda with 5 parts water. Baking soda works great on its own but feel free to add some vinegar to the mix for a bit of extra effectiveness

Feel free to transfer your cleaning solution to a spray bottle for ease of use.

Step 2:  Apply the solution to the affected area and clean

Lightly spray the solution directly onto the drywall mold and let it soak for a few minutes. Afterwards, gently scrub it down with an old sponge or toothbrush. The mold itself should come off easily.

Step 3:  Dry the affected area

Since water or humidity caused the mold problem in the first place it would be wise to not leave the wall wet. Dry the wall off with an old towel or cloth. Alternatively, let an electrical fan blow onto the area for a few minutes.

How to remove mold from unfinished drywall

Removing mold from unfinished drywall will take considerably longer and is somewhat more complex. There will be no actual cleaning involved – instead the sections of drywall which contain mold will be cut out and replaced. If you do not like doing this type of work then its recommended you employ the services of a contractor.

Step 1:  Cover the surrounding areas

Since we will be disturbing the mold during the removal process we have to use plastic sheets to cover the surrounding areas. This is important since disturbing mold will release countless numbers of spores into the air. Also ensure the room is well ventilated and be sure to wear a respiratory mask so you do not breathe any spores in.

Step 2:  Remove drywall containing mold

Carefully mark straight line squares with a pencil around the effected areas you want removed. Once done take a utility knife and carefully cut along the lines and remove the drywall. Be careful where you place the drywall pieces as they do contain mold.

Step 3:  Clean up the spores

After safely disposing the pieces of moldy drywall, throw the plastic sheets away and vacuum the entire area. it’s recommended to use a HEPA vacuum system but if you do not have one a regular vacuum is your next best bet.

Step 4:  Insert new pieces of drywall

Measure the square holes in the drywall you made and cut new pieces according to the measurements. If you like, you could paint the backside of the new pieces with mold resistant paint as an extra safety precaution because nothing is worse than mold that sits behind drywall. Insert the new pieces into the openings but be sure it fits nice and tight with no openings. Secure the new pieces with screws to the wood beams behind the wall.

Step 5:  Finishing Touches

Almost done! Simply apply some drywall compound around the edges of the new pieces. This will help secure it into position and close off gaps and cracks. Allow 24 hours for the compound to dry before using sandpaper to carefully even off the edges.