How to repair cracks in brick, stucco, mortar

Tom Petty once sang that “even walls fall down.” Just make sure they’re not your brick or stucco walls. Learn how to repair cracks in stucco, mortar, and brick to keep them from crumbling to pieces. Long live the walls!

What You'll Need

  • 1

    Gather tools

    You’ll need:

    • Mor-Flexx
    • Sashco Filler RopeTM or other backer rod
    • Drill-mounted brush or stiff bristled brush (grunt grunt “More power!”) for cleaning out the cracks
    • McKanica® silicone caulk remover or similar, if silicone is present
    • Caulk gun
    • Utility knife for opening the caulking cartridge
    • Trowels or foam brushes for smoothing
    • Damp rags for clean-up
    • Determination. Your walls will NOT fall down.

  • 2

    Clean the crack

    If you want your caulking job to stick and stretch for years to come, make sure you clean out old caulk, dirt, pollen, crumbling mortar and other contaminants. If silicone is present, use a silicone caulk remover.

    FLX Brick - Step 2

  • 3

    Insert Filler Rope™

    Any crack that’s deeper than ½” and wider than ¼” needs Sashco’s Filler Rope™ or some other type of backer rod so the caulking will properly stretch, and so you use less caulking.

  • 4

    Apply the caulk

    Be smooth about it now. A steady hand will save you cleanup later.

    FLX Brick - Step 4

  • 5

    Tool (smooth) the caulk

    Use a damp foam brush, a trowel or your trusty fingers to create a good-lookin’ bead and ensure the caulk is sticking to the sides of the joint properly.

    FLX Brick - Step 5

  • 6

    Clean up

    Use soap and water to clean up skin and tools. Sing that Tom Petty song with abandon, knowing they’re just song lyrics and not reality.

 Special Tip

For added peace of mind, prime the surface before applying the caulk. The bond between the two will be even stronger.