What Is Brick Spalling?
Brick spalling is a form of masonry deterioration where bricks crack, flake, or break apart due to moisture infiltration, environmental exposure, or structural issues. Over time, spalling can weaken a brick facade, compromise structural integrity, and lead to further damage if left unaddressed.
A common but preventable issue, spalling can affect entire sections of a brick wall, causing safety hazards and accelerating further masonry damage. Identifying the causes and implementing proper repairs is essential to preserving brick buildings, historic masonry, and commercial structures.
Common Causes of Brick Spalling
Brick spalling occurs when moisture enters the masonry system and weakens the material from within. Several factors contribute to this deterioration:
1. Freeze-Thaw Damage
- Water seeps into small cracks in bricks and mortar.
- As temperatures drop, water expands when frozen, breaking apart the brick surface.
- Repeated freeze-thaw cycles accelerate the breakdown of brick facades.
2. Hard Mortar and Incompatible Materials
- When mortar is harder than the brick, it restricts natural expansion and contraction.
- As the brick absorbs moisture and expands, the mortar prevents movement, causing cracks and layers of brick face to break off.
- Proper mortar selection should consider compressive strength and hardness (Mohs scale) to ensure compatibility.
3. Poor Drainage and Water Management
- Clogged weep holes or failing through-wall flashing trap moisture within the brick wall cavity.
- Water accumulates behind the masonry, causing internal pressure and accelerating deterioration.
- Proper drainage systems and flashing provide infiltrated moisture with a path to escape the wall assembly, reducing the risks negative impacts of water infiltration.
4. Non-Breathable Sealants or Paint
- Some sealants and coatings trap moisture inside bricks instead of allowing them to breathe.
- Over time, this trapped moisture causes efflorescence, cracks, and spalling brick surfaces.
5. Aging and Environmental Wear
- Exposure to pollution, rain, wind, and temperature changes gradually erodes bricks.
- Lack of maintenance increases the likelihood of brick face failure and widespread spalling.
Signs of Brick Spalling in Masonry Walls
- Flaking or peeling brick surfaces
- Cracks in individual bricks or mortar joints
- Layers of brick face breaking off due to incompatible mortar
- Loose or crumbling bricks in the facade
- Step cracking running through both mortar and bricks
- Bulging sections of the brick wall
- Efflorescence (white powdery deposits) indicating trapped moisture
If left untreated, spalling can spread through an entire wall, leading to structural instability and compromised masonry integrity.
Repairing Spalling Bricks
Surface-Level Spalling Repairs
If brick spalling is minor, maintenance and moisture control can help stop further deterioration:
- Cleaning and sealing – Removing efflorescence deposits and use a breathable water repellent (when appropriate) to reduce to risk of future moisture infiltration.
- Tuckpointing (Repointing Mortar Joints) – Removing deteriorated mortar and replacing it with a properly formulated, softer mortar mix.
Replacing Damaged Bricks
When bricks are severely damaged or structurally weak, they must be replaced:
- Carefully removing the affected bricks while protecting surrounding masonry.
- Assessing and replacing mortar to ensure proper hardness and flexibility for movement.
- Installing new bricks that match the original texture, color, and size for a seamless repair.
Addressing Structural Brick Spalling
If spalling has spread through both brick and mortar, larger repairs may be required:
- Wall rebuilding – Removing and reconstructing weakened sections of masonry.
- Flashing repairs – Fixing through-wall flashing failures and ensuring proper water drainage.
- Steel component assessment – Examining corroded lintels, anchors, and shelf angles for necessary reinforcement or replacement.
Preventing Brick Spalling in Masonry Buildings
To extend the life of brick facades and structural masonry, consider these long-term maintenance strategies:
- Use the Right Mortar Mix – Mortar should always be softer than the brick to allow for natural movement.
- Ensure Proper Drainage – Maintain weep holes, through-wall flashing, and gutter systems to direct water away from masonry.
- Apply Breathable Sealants – Avoid coatings that trap moisture inside the brick. Use masonry-specific water repellents when appropriate.
- Inspect Brickwork Regularly – Routine inspections help detect early signs of deterioration, allowing for proactive repairs.
Addressing Brick Spalling to Protect Masonry Structures
Brick spalling is a preventable but serious issue that affects historic buildings, commercial properties, and large-scale masonry facades. Proper repairs, combined with preventative maintenance, can extend the life of brick walls and protect against moisture-related damage.
At Building Restoration Corporation, we specialize in:
- Tuckpointing & Repointing for historic and modern brick buildings
- Brick Replacement & Mortar Repair using correct hardness and compatibility
- Moisture Control & Waterproofing to prevent long-term deterioration
- Structural Masonry Restoration for commercial and institutional properties
Contact us to discuss your masonry restoration or schedule an evaluation:
📍 www.buildingrestoration.com
📧 info@buildingrestoration.com
📞 612-789-2800