How to Mud Drywall

You’ve finished hanging drywall, and now you’ve got to figure out how to mud drywall. It’s not as hard as it may seem, and this article will address different types of mud, essential tools for mudding, and techniques for getting a perfect smooth finish.

Types of Mud

Mud, also known as joint compound, comes in several varieties:

• Taping compound: a high-adhesive mix designed for sticking tape to joints.
• Topping compound: a low-shrinkage mix designed for second and third coats.
• Low dust compound: designed for remodeling use, when dust control is essential.
• Lite compound: about half the weight of standard product, used in mechanical taping devices.
• All-purpose compound:  just what it sounds like—a good compromise for taping and top-coat purposes.

Unless you’re buying drywall mud in professional quantities, you’ll probably do just fine with a quality all-purpose, multi-use joint compound.

If you’re hanging drywall as part of a renovation, you might consider the low-dust mix. However, realize that any form of drywall dust can potentially cause respiratory problems, and remember to wear a respirator and clean the area thoroughly after any dry-sanding. Strongly consider wet-sanding as a way to avoid excessive dust.

How much mud do you need? Two large buckets for every 500 square feet of drywall will get the job done and cover any mistakes or other waste.

Mudding Tools

Applying drywall mud is not difficult, but it does require a refined touch and the right tools.  You’ll want to acquire:

• Steel mudding knives. Standard widths are 6 inches, 10 inches, and 12 inches.
• Corner trowel, a must for handling corners.
• Mud pan for holding mud and loading knives.
• A drywall hawk, a type of flat palette that will allow you to mix and carry mud conveniently.

Getting the Mud on the Wall

Mud is used to conceal screw holes and joints between sheets of drywall.  Mud is applied to these areas in three coats, with 24 hours drying time between coats. To ensure a smooth wall, each layer is an inch or two wider than the last, and each layer consists of a “skim coat” — a very thin coat that levels and fills gaps in the underlayer. That’s the big picture when it comes to mudding.

To get things started, fill a joint with plenty of mud, and press a length of tape into the wet joint.  Use a 6-inch knife to press the tape into the mud, squeezing out the excess and smoothing the layer to the left and right of the joint. Allow the joint to dry. On succeeding days, use progressively larger knives to skim wider coats over the joint. Use long smooth strokes–short strokes will leave marks that must be sanded out.

For screw holes, begin by hitting a hole with a generous amount of mud, then scrape away the excess. Use a 6=inch knife, keeping the blade relatively flat to the wall, instead of perpendicular to it. As with the joints, in the coming days you’ll use larger knives to cover wider areas around each hole. The result will be a smooth, undetectable fill.

You’ve hung your drywall, finished mudding the joints, and now it’s time to prime and paint!