How to Clean Drywall and Joint Compound (Mud)

Woman with drywall sanding tool
Susan McDougall Photography / Getty Images

This guide deals with two types of drywall-related cleaning:  cleaning the unpainted paper surface of drywall and cleaning up dried drywall joint compound, or mud.

Cleaning Drywall

Drywall gets dusty over the course of a home remodel project.  Since painting comes last in most projects, that unprimed, unpainted drywall has accumulated a fine layer of sawdust, drywall dust, and other debris.

Not only that, because drywall's outer surface is paper, the problem is worse:  paper is a dust-magnet.

Paper does not like water.  This is your key problem with cleaning drywall's outer surface.  Begin with dry-cleaning methods before proceeding to liquid-based methods:

  1. Vacuum:  Clean with the wide nozzle and/or brush nozzle on your shop vacuum.
  2. Tack Cloth:  For small areas, use tack cloth to very lightly wipe off debris.  However, pressing too hard will embed wax in the drywall paper, so go easy.
  3. Wet-Clean:  Wet a drywall sponge and then squeeze it all the way out.  The sponge will feel almost dry in your hand.  Begin at the top of the drywall and, with gentle pressure, pull in downward strokes.  Rinse out and squeeze the sponge frequently.  Change out the water when it begins to get murky.

Note that this guide refers to bare, unpainted drywall.  If you have painted drywall, this acrylic-latex surface is impervious to water.  Thus, you can use warm water and a non-abrasive all-purpose cleaner.

Cleaning Drywall Joint Compound (Mud)

Cleaning dried drywall joint compound, or mud, is tough.  After all, drywall mud is intended for the long haul. It is intended to help cover and keep seams secure for many years. 

1. Develop Methods to Avoid Mess Before Mess Starts

  • Go Easy With Mud:  Learn to not over-apply drywall mud.  After all, the more mud you apply, the mud you will need to sand down later on.  If the drywall sheets are properly installed--flat on the studs and with narrow seams--you do not need to use much mud.
  • Cover Surfaces:  Use a canvas dropcloth to cover surfaces that may get slopped on.

2. Clean Up Within Seconds

Have a paper towel or rag with you at all times to clean up the mess. Do not let it sit more than a few seconds before wiping up.

3. Use Lukewarm to Hot Water

For goopy, semi-set drywall mud, you can soak tools in hot water for about ten minutes.  Compound is water-soluble, so the mud should easily shed off.  For surfaces, lightly rub off with a warm, damp cloth.

4. Scrape Dried Mud

Drywall compound that has fully dried will not soak off. You can soak your tools for days and still not soak it off.

Scraping is your only recourse.  If this is a drywall tool, use another drywall tool or a putty knife as a scraper.  If this a delicate surface such as a floor, try gently hitting the dried mud with a cloth-wrapped hammer or a rubber mallet to break it up.  Then scrape with a plastic implement.