How Does Drywall Mud Work?

Drywall mud is a joint compound that is used to affix drywall joint tape to drywall seams. It is used in building projects such as home construction. The drywall mud helps to further hide a seam and prepare the wall for painting or wallpapering.

What Are the Components of Drywall Mud

Drywall mud is made of a combination of materials, which include:

  • Perlite, a rock compound
  • An ethylene-vinyl acetate polymer
  • Limestone
  • Attapulgite, a magnesium-aluminum compound

These ingredients are premixed with water (or can come in a dry mixture that requires water to be added) and form a creamy, smooth paste. The pasty mixture looks like mud, which is how it got its name.

How Is Drywall Mud Applied?

Drywall mud is most commonly found in pre-mixed tubs, available in hardware stores, home improvement centers and paint stores. It is ready to use and lasts longer than other traditional joint compounds. A joint knife or putty knife and trough are used to apply the compound to the joint, once drywall joint tape has been applied.

The joint knife is used to smooth the mud and cover the tape and seam. Once the compound dries, a sanding tool is used to sand away the excess amount and leave the wall surface level and smooth.