Masonry Cracks

As houses settle over time, the foundation shifts and can lead to cracks in immobile materials such as brick, stucco and stone. Minor shifts are normal and will produce hairline cracks. Deeper cracks that leave big gaps may indicate a structural problem with your home. To repair minor cracks in your masonry, use the following guidelines.

How To Repair Cracks In Stucco
Clean off loose stucco and dirt with a stiff brush. Use a putty knife, smooth trowel or caulking gun to fill in the crack with latex caulk or, if it is a wider crack, use a concrete bonding material. To create a harmonious look with the rest of your siding, you will need to apply stucco, applied with a putty knife or trowel. Try to apply it so the texture matches the pattern.

How To Prevent Cracking
Keep the stucco moist for 4-5 days by watering it as often as the weather demands. Once the stucco has cured and allowed to dry, paint with matching house paint.

How To Repair Cracks in Brick or Stone
Use a brush to clean off dirt around the crack. Use a putty knife or smooth trowel to apply concrete bonding material that has been stained to match your brick or stone (available at home improvement stores). Once dry, sand with sandpaper until area is level.

How To Repair Crumbling Mortar Around Brick or Stone
1. Use a chisel and small hammer to chip out deteriorating mortar as deep as you can, preferably a ½ inch or deeper. Clean the crevice with a stiff brush. Hose out area and then dry with a towel until it is moist, not wet.

2. Mix weather-resistant "N" type mortar to the consistency of peanut butter. Load mortar onto a "hawk," or another wood or plastic surface — an old cutting board will suffice.

3. Force fresh mortar into damp crevices with a putty knife or smooth trowel. Pack tightly.

4. Allow mortar to dry enough to be stable, but still soft enough to show your thumbprint when touched. Now you will do some cosmetic edging of your new mortar. Starting with the vertical mortar joints, force the mortar in deeper and smooth its surface by running a tool called a "jointer" from top to bottom. You can also use other makeshift tool replacements, like a tongue depressor, a piece of flat plastic, or even your lightly moistened finger.

5. Now do the same of the horizontal joints, running your tool side to side across the fresh mortar.

6. The mortar "overflow" that edges onto your bricks or stones can be trimmed off by sliding a trowel over the affected masonry.

7. Repeat the process again: first on the vertical joints, then the horizontal. Trim overflow again if needed.

8. Once the mortar is set, clean area with a stiff brush.

9. Keep new mortar moist for 3-4 days to prevent cracking.

Trying to repair your masonry cracks? Visit our Siding forum and consult with other DIYers on your DIY project.