To achieve seamless joints with flat smooth surfaces when installing drywall, a technique called “mudding” is required. The process may sound like something that could end up being a messy process, but a basic application of premixed mud/compound is relatively easy to do.
Types of Mud
There are two types of drywall mud: powdered and premixed. The powdered compound, which is also referred to as setting mud, requires mixing with water. Premixed mud has already been blended and is ready to use.
Premixed also comes in various types such as all-purpose, topping mud, and lightweight all-purpose mud. Powdered mud is available as timed drywall mud and easy-to-sand setting mud.
Types of Tape
Mud and tape go hand-in-hand. They are a team working together as a bonding unit. The combination prevents cracks in the finished wall. The three types of tape are pre-formed, mesh, and paper.
Steps for Mudding Drywall
For example purposes, this article discusses how to mud drywall using paper tape and all-purpose premixed drywall (joint) compound.
Place the canvas drop cloth over the entire floor. It’s recommended to use canvas versus plastic as plastic tends to become slick when drywall splatters adhere to the cloth’s surface.
Prepare yourself from drywall splatter by putting on old clothes and protecting your eyes by wearing goggles or safety glasses.
Remove the lid from the premixed mud. Place the large bucket filled with water nearby so you can clean the taping knives as you work.
With the drywall panels mounted and secured, place a quantity of mud on the mud pan or tray. Use the 6-inch taping knife to scoop up and place a dab of mud to fill in and cover screw indentations and nail heads. Use the knife edge to smooth out the mud.
There will be spaces or small creases (joints) where drywall panels meet. Using the 6-inch taping knife, apply mud evenly along the joint filling in the space. Smooth out the mud using the knife edge.
While the applied mud is still wet along the seams/joints, cut a piece of paper tape the length of the seam and place it along the joint. Press the 6-inch taping knife against the tape and gently smooth it into the still wet mud. Press gently but hard enough to work out any bubbles created in the mud. Use the knife edge to wipe away any excess compound.
Use the same steps for applying mud to both sides of the corners and then use the corner taping tool/trowel to evenly spread the mud. Place a pre-cut and pre-creased length of paper tape along the seam. Use the 6-inch taping knife to smooth the paper tape over the mud. Take the edge of the knife to work the tape gently into the corner. This is referred to as “bedding.” Remove excess mud with the taping knife.
Let the applied mud dry thoroughly. Once dry, apply a thin second coat of mud to screw and nail indentations and corners.
Let dry, then apply a very thin third coat of mud using the 10-inch taping knife. Use the knife edge to “feather out” the mud so the edges are as thin as possible.
Let dry. Put on goggles and respirator in preparation for sanding the mud.
Use your choice of sander to smooth out all mudded joints and screw and nail indentations. The goal is to sand the mud until it's completely smooth. You do not want to leave rough edges along the seams, nor do you want to leave raised areas of mud on the wall. The drywall mud should be sanded until it's flat and smooth.
Once the mud has been sanded to perfection, the wall is ready to be painted or have wallpaper applied.
Warning: When using a sander, be sure to wear the respirator and the goggles as the mud creates a fine dust. The goggles also serve to protect eyes from mud splatters.