How to Repair Cracks in an Interior Stucco Wall

Although interior stucco is not used as much in home construction as exterior stucco, when it is used the homeowner will need to know how to repair it when it develops crack; otherwise, he will find himself paying the expensive costs of hiring a contractor to do the job. With the right instructions, materials, and tools, if you are the homeowner with an interior wall that needs repairing because of cracks in your stucco, you can save yourself this expense and still have a professional-looking repair. All it takes is some time and information, which the following can provide you:

Things you'll need:

  • Broom
  • Stiff brush
  • Chisel
  • Compressed air
  • Caulking gun
  • Sponge
  • Stucco mortar
  • Garden hose
  • Bucket
  • Mixing paddle
  • Towel
  • PVA glue
  • Bitumen-coated fiberglass cloth
  • Paint roller
  • Primer
  • Paint
  • Paintbrush

Step 1 – Prepare Your Stucco

To prepare your cracked stucco surface for repair, you will first need to remove from the surface of the stucco all loose stucco around the cracks. If you find it necessary, use a hammer and chisel to free loose or broken stucco from areas where it is partially stuck to the wall. Use a whisk broom, stiff brush, or compressed air to clean out any dirt or fine debris that is left in the spaces where your stucco has been removed. If you have cracks in the remaining stucco surface, clean out any dust, dirt, or debris from these cracks.

Step 2 – Caulk Cracks

Fill small cracks with caulk using a caulking gun. In cracks that are too small for the caulk gun nozzle to fit into, apply the caulk and push it into the crack using your finger or a putty knife. To remove excess caulk remaining on the surface near the crack, wipe it off with a damp sponge or clean rag. Allow one hour for the caulk to set up, then, saturate your stucco surface that is near the repair area, using a garden hose and wet sponge.

Step 3 – Apply PVA glue

To the area where you've removed stucco, or to the interior of cracks, apply PVA (polyvinyl acetate) glue or white glue. After three or four minutes, when the glue has dried, apply mortar to the cracks and the areas where you've apllied glue. Lay a coating of bitumen-coated fiberglass cloth over the glue and use a paint roller to press this patch against the repaired wall surface. As a second option, close thin cracks and seal the stucco surface by applying an acrylic elastomer spray. 

Step 4 – Apply Primer

When your fiberglass and glue patch have dried, apply a primer over the entire wall surface. You may be tempted to prime only the patched area, but keep in mind that in doing this you will see a contrast in finished colors of the repaired wall surface and the unrepaired wall surface. When you've finished applying the primer, allow it to dry.

Step 5 – Apply Stucco Paint

Use a paint roller to paint the wall on which you applied your primer. Paint the entire wall. If necessary, when the paint has dried, apply additional coats of paint.