Spalling Brick, Open Mortar Joints, And Moisture Damage

If you notice brick faces flaking, mortar joints opening up, and moisture stains appearing on your historic masonry home, these conditions are often connected.

What may look like three separate issues can actually be signs that moisture is entering the masonry and causing deterioration over time.

What Causes Spalling Brick and Open Mortar Joints?

Mortar joints help limit water entry while allowing moisture within the masonry to dry.

As mortar deteriorates, gaps can form between the bricks, allowing additional rainwater to enter.

Poor drainage, leaking gutters, failing flashing, and incompatible mortar can also contribute to moisture issues.

When water enters the brick and repeatedly freezes and thaws, the expansion can cause the outer surface to crack, flake, or break away. This type of deterioration is known as spalling.

Over time, continued moisture exposure can lead to further damage to both the bricks and mortar joints.

How to Address Brick Spalling and Moisture Damage

The first step is identifying where the moisture is coming from.

Checking gutters, flashing, drainage, and deteriorated mortar joints can help determine how water is entering the masonry.

Once the source of moisture is corrected, open or deteriorated joints can be repointed using compatible mortar suited to the original masonry.

Severely damaged bricks may need to be carefully replaced, while original bricks that remain in good condition should be preserved whenever possible.

Repairing the visible damage without correcting the moisture source can allow the same conditions to return.

For more information about repairing deteriorated mortar joints, learn about brick repointing.

Why Early Masonry Repairs Matter

Spalling brick, open mortar joints, and moisture damage generally do not improve on their own when water exposure continues.

Addressing these conditions early can help limit further deterioration, preserve original brickwork, and maintain the character, durability, and appearance of your historic masonry home.

More importantly, correcting the source of moisture helps extend the life of the masonry and reduces the likelihood of more extensive reconstruction in the future.