How to Skim-Coat a Wall

Prepare the wall for skim-coating by stripping any existing wallpaper, scraping off peeling paint and filling cracks in drywall or masonry. In addition, apply a coat of stain-blocking primer if the wall has grease or rusts spots. These spots may bleed through the skim coat.

Remove outlet and switch covers and put masking tape over the interior switches. Tape around permanent fixtures, such as door trim and window trim. You may remove the baseboard or put a layer of protective tape on it.

Stir the premixed drywall until smooth. This mud comes prepared in 5-gallon buckets. Upon sitting, it can form small lumps. Use a large wooden spoon to stir small amounts. Alternately, a mixing bit attached to a heavy-duty power drill easily blends drywall mud.

Fill your drywall bucket about half full. When skim-coating an entire wall, you will use this amount to skim approximately 4 square feet of wall surface.

Scoop out about 1 cup of mud and smooth it on the wall, beginning in a lower corner and using an upward angled motion to spread a thin, even coat on the wall. Use a consistent pressure and overlap your strokes to pull excess mud towards the edge. Repeat this process until your drywall bucket is nearly empty.

Continue in the same manner quickly, filling the drywall bucket again and spreading the mud on. It's important to keep going once you start to avoid lap marks. Try to keep a "wet edge" on the wall at all times between coating areas. Work your way across the wall and upwards to the opposite corner.

Allow the wall to dry and use the wall sander to remove lumps and uneven patches. As you practice the skimming technique, you will develop a method of spreading the mud evenly. The less excess you leave on when the mud is wet, the easier it will be to sand when it's dry.

Finish the sanded and smooth wall with paint or wallpaper.