Pro Angle Masonry Charleston can add value and improve the look of your home. But like anything else, it requires maintenance to keep it in good condition. In traditional masonry buildings, thick load-bearing walls are often supported by steel lintels at openings such as doors and windows. Frame houses, on the other hand, tend to use wood lintels for similar reasons.
In a masonry wall, forces such as temperature changes, the introduction of moisture (resulting in a volumetric change of the materials), and corrosion of embedded steel elements can cause the face of a brick to crack and fall away from the rest of the masonry. The condition is called spalling. Spalling can be limited to a single brick or cover entire expanses of a building. When a portion of a masonry wall begins to spill, it presents a potentially risky situation as it can fall from the building and impact people or property below. If the spalling is extensive, it can require a complete reface of the masonry wall section.
Masonry professionals will often inspect spalling for an underlying issue that needs to be addressed. For example, if the spalling occurs along a stairway or entryway of a home, a mason may need to install a new expansion joint to reduce the stresses in that area of the masonry wall.
Another common repair is to replace a spalling brick with a new, matching brick to ensure that the appearance of the wall is maintained. A mason will also look at the surrounding bricks to determine if they need to be replaced. The most serious type of masonry spalling is when a brick’s shelf angle begins to erode. The shelf angle is an L-shaped metal unit installed behind a row of bricks to balance the weight of the bricks against the ground they’re attached to. When the shelf angle corrodes, it won’t be able to do its job properly.
Other spalling causes can include a substandard mortar mix during construction or using a cement-pointing product over soft lime mortar joints. It blocks the mortar joints and exacerbates spalling as the interstitial moisture tries to escape the brick faces. Masonry sealants should be avoided, especially on historic brick buildings — they trap moisture and salts that can further damage the masonry.
Other signs of spalling masonry can include:
- Bowing foundation or first-story walls.
- Cracks in the drywall.
- Windows and doors that don’t open and close easily.
Enlisting the help of a masonry repair company can prevent these problems from deteriorating further and save you more money in repairs down the road.
Mortar decay is a serious issue for brickwork. It erodes and disintegrates the mortar joints, where water can soak in and cause damage. Brick walls deteriorate at the mortar joints, and it’s important to repair them as soon as you notice the signs of wear.
Mortar joints deteriorate whenever water can soak in, including under windows and around chimneys, at the wall-ground line, at the eaves along the roofline, or anywhere else exposed to the weather. Eventually, the mortar joints will delaminate from the masonry units (bricks, stone, or concrete blocks), and the faces of the units will spall, crack, and chip. The damage will accelerate if it isn’t repaired.
The deterioration of the mortar is the result of moisture penetration that causes the mortar to shrink and swell. It creates a gap between the bricks, and when there are enough gaps, the water penetrates the masonry unit and corrodes the mortar bond. The deterioration of the mortar also exposes more surfaces for water to penetrate, and this cycle of exposure and corrosion will continue until the masonry reaches its point of failure.
When the masonry is damaged, it’s time to scrape out the old mortar and trowel in new, a process called repointing. It is a simple job, but it must be done correctly to preserve the integrity and appearance of the brickwork. It requires special skills and tools to do it right so the work will look good and last for years.
Traditionally, masons used lime mortar, which allows historic masonry to breathe. This mortar type is less dense than Portland-based mortar, which can be too rigid for historic masonry. Many masonry contractors today use hard, Portland-based mortar, which is incompatible with landmark masonry and will quickly cause problems. Using only traditional materials, such as mortar formulated for historic masonry, is critical when tuckpointing or repairing a brick building.
Jeff recommends starting with a visual inspection of the building. Look for previous tuckpointing repairs, especially on large wall areas exposed to the weather, and check mortar shape, depth, and consistency. A good test is to drag a metal key across or into the mortar joint and see how easily it penetrates; if it penetrates, it’s likely time to repoint.
Generally speaking, masonry walls are sturdy and durable; however, several problems can plague these structures, including cracking, damage, and collapse. These issues can be caused by weather conditions, water penetration, and steel corrosion embedded in the masonry.
The rusting of steel lintels and angles commonly causes home-angle masonry corrosion. These elements are essential for the support of masonry over door and window openings. They’re usually made of steel angle, channels, or wide flange beams and are susceptible to corrosion from repeated exposure to moisture. When these lintels corrode, they expand and cause deformation in the masonry above them. It can lead to large cracks, air or water infiltration, and disjunction of bricks. If the lintels are not replaced promptly, the brick wall above them can collapse.
Other structural components in masonry walls vulnerable to corrosion include routed cells, collar joints, and steel rebar in bond beams. It is because these components are exposed to atmospheric and other environments that can allow moisture to penetrate. These materials can expand up to six times their original volume when corrosion occurs. This expansion enables further moisture penetration and perpetuates the cycle.
Another problem with masonry structures is spalling. It is a type of damage in which concrete breaks up and flakes away, often near the surface. It can be unsightly and may be a sign of structural issues, so a qualified masonry professional should examine it.
A less obvious symptom of corrosion in masonry is a stepped fracture known as “oxygen jacking.” It is an elegant form of fracturing seen in the Parthenon marble. It results from a rusted angle iron expanding and pushing on the masonry above it, creating a stepped crack.
The best way to prevent rust and corrosion in home angle masonry is by protecting it from moisture with a self-adhesive BlueskinTM membrane. This membrane waterproofs the structure and protects against ice dams, water infiltration, and masonry degradation.
Brick is a durable material, but it’s not impervious to damage. Whether from the pounding of the weather or a careless worker, damaged bricks should be repaired immediately to prevent more serious damage to the rest of the wall and possibly the foundation of your home.
Typically, the discoloration of bricks from moss and mold is harmless. It can result from pollution and other airborne contaminants but can also occur when moisture penetrates the brick wall. It may be due to a bad insulation job that allows moisture into the wall or caused by water penetration through an existing leak.
While stains don’t indicate critical damage, they are often unattractive and can be hard to clean. A professional mason can address this problem by removing the stains with muriatic acid and then repointing the mortar joints.
A bowed brick area is when the bricks in a wall either jut out or cave around a particular section. It indicates that the bricks absorb excessive moisture and need to be remedied immediately before lasting damage is done. Water that seeps in behind the brick either warps and pushes them out or softens the materials underneath, causing them to sink in.
If the bowed bricks are due to poor drainage, then improving the drainage system can help. It could also involve repairing leaks, such as water splash from badly fitted gutters, reducing sources of moisture penetrating the brick walls. Alternatively, if the bowed bricks are due to structural problems, a mason can carry out mudjacking to lift and level the foundation in the affected area.
Brick walls should be repointed periodically. It includes the tops and bottoms of the brick and the vertical mortar joints. It’s important to use a compatible mortar mix and ensure the surface is clean of paint or other sealants before parging. It’s also important to understand that repointing isn’t just fixing the visible areas of damaged brick but also addressing the source of the damage, or else spalling will continue.