Insulation 5 - Repairing the Wall Insulation 5 - Repairing the Wall
Margin of Error: Exact
To patch holes in a plaster wall, fill the hole with newspaper or wire mesh (metal lath). Cut the wire mesh to be one larger than the hole all around. Tie a 5" string through the center of the mesh and a pencil at the other end. Push the mesh through the hole and twist the pencil until it is tightly spanned against the wall. Apply spackling compound to within 1/4" of the surface. Allow it to dry completely; then cut the string to remove the pencil. Apply a second layer of spackling. Sand when it dries.
Holes in drywall can be repaired using a "hat patch" technique. After removing the damaged portion of drywall, undercut the edges for a good clean opening. Then tear off 1/2"-1" of the paper around the perimeter of the hole so that only the bare gypsum is showing. Cut a piece of drywall to the exact shape and dimension as the area defined by the bare gypsum. Remove enough of the gypsum from this piece so that you are left with a plug (the size of the hole) with a paper "brim" that will cover the bare gypsum. Finish the patch by mudding the seam with drywall compound.
After the holes are filled in and dry, the wall must be smoothed. Use a hand sanding block or an orbital sander fitted with 120-grit sandpaper for a finish that is smooth, flat, and flush again.
There is no vapor barrier in place when blown-in cellulose is used. Even though it has been treated to resist moisture and deterioration, you may want to paint interior walls with an oil-based, non-breathing paint to act somewhat as a vapor barrier. Do not paint the exterior with a non-breathing paint or it will trap moisture in the wall.