How to Clean Drywall Dust and Joint Compound

Wood dust vacuum
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Drywall allows you to build soundproof walls much faster than in the old days when plaster and lath were the only way to create interior walls.

But expediency does come at a price. The drywall dust that results from cutting drywall and from sanding down cured joint compound is hard to clean up. In addition, joint compound is hard to clean up, whether in wet or dry form. But a few techniques can help minimize the work and the dust.

Cleaning Drywall Dust on Drywall

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

Drywall is faced with paper. Paper does not respond well to cleaning with water. This is the key issue with cleaning drywall's outer surface. Not only that, when you apply water to drywall dust, the dust begins to harden.

So, begin with dry-cleaning methods before proceeding to liquid-based, damp methods:

  1. Brush: With your dust mask on, lightly brush dust off the walls with a soft broom or hand brush. Move somewhat slowly from top to bottom. Sweep the dust from the floor afterwards and before the next step.
  2. Vacuum: Wearing a dust mask, clean the drywall with the wide nozzle and/or brush nozzle on your shop vacuum. Start at the top and work downward. Do not press too hard. Keep the pressure light to avoid embedding the dust into the porous surface of the paper.
  3. Tack Cloth: For small areas, use a tack cloth to very lightly wipe off debris. Pressing too hard on the tack cloth will embed wax in the drywall paper, so go easy. Once the wax has become embedded, it is extremely difficult to remove.
  4. Wet-Clean: Wet a drywall sponge and then squeeze it out. The sponge will feel almost dry in your hand. Begin at the top of the drywall. With gentle pressure, pull the sponge in downward strokes. Rinse out and squeeze the sponge frequently. Change out the water when it begins to get murky.

Cleaning Drywall Joint Compound (Mud)

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

Time is of the essence. As long as the joint compound is wet or even beginning to harden, it can be cleaned off with water. If the joint compound has hardened, water will not help: it must be sanded or scraped.

Avoid Messes Before They Start

  • Use a Drywall Mud Pan: Eliminate the problem before it starts by keeping clean. Using a mud pan is the easiest way to limit drywall mud mess. If you are in the habit of taking drywall mud straight out of the bucket, you may be surprised by how much easier (and cleaner) it is when using one of these elongated pans designed for the shape of drywall knives.
  • Go Easy With Mud: Learn to not over-apply drywall mud. After all, the more mud you apply, the more 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 drop cloth to cover surfaces that may get slopped on.

Clean Within Seconds

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

Use Lukewarm to Hot Water to Clean

For goopy, semi-set drywall mud, you still have a grace period where you can possibly use water for cleaning. Once the joint compound has been allowed to harden, water will have a greatly reduced effect.

You can soak tools in hot water for about 10 minutes. All-purpose joint compound is water-soluble, so the mud should easily shed off, though you may need to use a brush.

Lightly rub off with a warm, damp cloth.

Scrape or Sand Dried Joint Compound

Drywall compound that has fully dried will not soak off. You can soak the surface or your tools for days and still the drywall compound will not effectively soak off.

At this point, sanding or 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 tapping the dried mud with a cloth-wrapped hammer or a rubber mallet to break it up. Then scrape with a plastic implement.