How to Remove Mortar Deposits From Brick and Masonry

Unwanted mortar deposits are unattractive on bricks and other masonry.

Known for its flexibility and bond strength, mortar holds bricks, concrete blocks and other individual masonry units together. Accidental mortar spills and smears, however, leave mortar deposits on brick and other masonry surfaces during masonry repairs. Mortar is a mixture of cement, water, hydrated lime and sand, which bonds to masonry as it cures. The bond between mortar deposits and masonry increases over time, making the deposits increasingly harder to remove from masonry. Promptly remove mortar deposits from brick and other masonry.

Things You'll Need

• Garden hose
• Stiff-bristle brush
• Hammer
• Cold chisel
• Long clothes
• Rubber boots
• Acid-proof gloves
• Protective glasses
• Plastic dropcloths
• 1 cup muriatic acid
• Bucket
• Stirring utensil
• Garden sprayer

Instructions

1. Spray the masonry with water, flushing the mortar deposits completely. Scrub any fresh, uncured mortar fragments off the masonry using a stiff-bristle brush.

2. Remove any hardened mortar deposits off the masonry using a hammer and cold chisel. Position the chisel's tip 45-degrees to the masonry and hammer the chisel's dull end to chip off the hardened mortar. Remove as much mortar deposit this way as possible.

3. Prepare to remove the lingering mortar deposits with muriatic acid. Put on long clothes, rubber boots, acid-proof gloves and protective glasses to prevent acid-related burns. Cover nearby landscaping with plastic dropcloths.

4. Combine a solution of 1 cup pure muriatic acid with 10 cups water in a bucket. Mix the pure muriatic acid into the water. Never add any water to muriatic acid.

5. Moisten the masonry liberally with water to inhibit acid-related damage.

6. Pour the diluted muriatic acid solution into an old, yet clean, garden sprayer. Spray the diluted acid solution onto the remaining mortar deposits. Let the acid solution remain on the mortar deposits for 10 minutes.

7. Scrub the remaining mortar deposits off the masonry using the stiff-bristle brush.

8. Rinse the masonry generously with water. Thoroughly flush all diluted muriatic acid solution off the masonry surface.

9. Discard any leftover diluted muriatic acid solution in compliance with local city ordinances.

Tips & Warnings

• Remove fresh mortar deposits with white vinegar.

• Muriatic acid can burn exposed body parts.

• Never mix muriatic acid with anything other than water.

• Spot-test the diluted muriatic acid on the masonry to prevent discoloration.

References

• Fine Homebuilding; Mortar: What Type Do You Need?; David Ericson
• Ask The Builder; Remove Brick Mortar; Tim Carter
• Cement Concrete and Aggregates Australia: Removal of Mortar