The image of any building constructed with masonry typically conjures thoughts of a structure designed for permanence and durability - a construction so sound that it will last through many decades. After all, masonry structures dating to ancient times still stand tall in many places all over the world. Yet over time, even the most soundly designed and constructed masonry buildings require some attention. Extreme weather conditions and the general effects of time may lead to a need for masonry repair. Or, in some cases, poor building design or construction may be the cause.

Left unrepaired, masonry damage can lead to numerous problems including water leaks, decreased property value, increased energy expenses and personal injury. By recognizing the symptoms and taking action, however, owners can avoid the pitfalls of masonry issues. A building owner may notice cracking at the corner of the building or a step cracking off of the corner of an opening, efflorescence or deteriorating mortar joints. Random cracking and spalling of the brick façade, parapets that are bowed or have moved away from the building at the corners, cracks at foundation corners, and cracks at the wall's offsets all are symptoms that should be investigated to determine the root cause.

Contemporary structures and buildings constructed prior to 1920, often referred to as historic buildings, usually have very different root causes of masonry damage. Therefore, each building type requires an understanding of the construction method to determine the root cause and potential repair options. Regardless of the building's age, seeking attention at the earliest sign of problems, avoiding common misconceptions and following the counsel of a qualified restoration contractor or restoration design professional will go a long way toward managing the problem effectively.

Considerations for Contemporary Masonry Repair

When an owner of a contemporary structure notices signs of masonry problems, he or she must take immediate action toward the identification of the symptom, determine the root cause for the masonry defect or deterioration and determine an appropriate repair method. Unfortunately, in many circumstances, the owner hires an unqualified roofing, waterproofing or window cleaning company to caulk the holes and/or waterproof the masonry. This leads to wasted expense and potentially creates a far greater challenge for a future prudent repair. Simply put, caulking and waterproofing in most contemporary masonry structures are not going to solve the problem, especially structural and or water infiltration challenges. Determining the root cause behind the problem is essential.

Common Misconceptions: There are many misconceptions regarding masonry repair. Dispelling these myths can help owners seek an appropriate, timely repair path and ultimately save money.

First, it is important to understand that contemporary structures are often constructed as water-managed walls such as a cavity wall. A water-managed wall is designed and built to prevent leakage based on the theory of "control and discharge." Anticipated and accepted amounts of water that penetrate the exterior surfaces are controlled and discharged. A masonry water-managed wall would have a masonry veneer and a back-up wall of concrete block or a stud wall with sheathing. Part of the masonry back-up, in most circumstances, includes the concrete slab edge. The masonry veneer is connected to these back-up wall materials with a wall tie system. The key component to this capture and release theory is the flashing. The flashing redirects the captured moisture and water to the building's exterior through weep holes and along lintels.

Unfortunately, very rarely is the wall system understood. A roofing/waterproofing/window cleaning company may first attempt to repair the leaking with caulking. The lintels, and possibly even the weep holes, may be caulked shut. Depending on the actual construction method of the wall, caulking these areas can make the leak worse and/ or trap water in the cavity where unprotected steel can begin to corrode excessively, which creates rust jacking and masonry veneer damage. Also, this trapped water can create mold issues and possibly even an unhealthy interior environment for the people occupying the space.

Another common mistake occurs when waterproofing is sprayed on a water-managed wall to stop leaks. This process fails to use the control and discharge of the wall system the way it was designed. Such a practice is a waste of money and without a real understanding of the waterproofing materials, false hope of a repair results. In addition, application of the waterproofing material can cause damage to the landscaping and to the structure in the form of damaged glass and stained brick work. Further, if the brick is a glazed face brick, waterproofing may actually introduce brick spalling because the waterproofing reacts to the glazing. However, once an owner understands the purpose of cavity walls, they can appreciate the function of these systems to a building's design.

Similarly, cracks in the veneers are often mistakenly repaired by caulk. But, without identifying the root cause of the cracking, spending the money on caulking may be wasteful. If the cracking is due to insufficient wall ties, inappropriate expansion joint locations or other potential masonry challenges, caulking of the crack will not provide any actual benefit.

Repair Process: In many cases, there's simply no way around it. Masonry issues on a contemporary structure often require significant repairs. However, repairs will vary from short-term to long-term solutions, depending on how long the owner plans to possess the building. Regardless of the solution the owner wishes to take, determining the root cause of the problems is an important first step in any repair project.

A sign of masonry problems, such as leaks, cracking, wall bulging, lintel jacking or just finding masonry pieces on the sidewalk, all may indicate larger problems with a contemporary masonry building design or construction. Today's fast-paced construction schedules often result in too little information to construct properly-working contemporary masonry walls, especially water-managed masonry walls. And, there is zero tolerance for design and or construction error with water managed walls. As a result, owners are often stuck making an enormous investment in their property in the first couple of years because of a lack of details or material specifications, absence of planning the details or testing a constructed mock-up on-site, no follow-up testing in the field, as well as lack of inspection by a professional. To remediate masonry problems resulting from improper design or construction, a qualified contractor will begin by interviewing the owner to learn more about the actual problems as well as the owner's intent. The contractor will need to know if the owner plans to hold the building for a long-term investment or if the owner has a short-term commitment to the property and therefore would prefer not to invest a significant expense.

In the initial phases, a contractor also must examine the original drawings and perform a visual inspection to determine how the building was originally constructed. By doing so, a contractor can establish a root cause of the problem and define a proper course of action. A visual inspection should follow the guidelines established by the American Society of Testing and Materials (ASTM) in standard E2270 Periodic Inspection of Building Facades for Unsafe Conditions. According to ASTM E2270, a general inspection at greater than 6 feet from the building can be performed with binoculars to scan the facade to check for out-of-plane displacement of facade elements, while scanning the facade horizontally and vertically. A detailed inspection within 6 feet of a building involves visual observation and tactile evaluation of façade components includes probing and non-destructive testing (NDT) to observe concealed conditions of wall construction. This level of inspection requires tactile contact with facade elements. The Qualified Inspector shall use, at a minimum, the following techniques in performing the inspection:

• Check horizontal surfaces that can pond water (such as sills, ledges, cornices, water tables and other such horizontal bands) from above wherever possible.
• Check for out-of-plane displacement of façade elements, while scanning the facade horizontally and vertically, as well as check for signs of staining, spalling, water or moisture damage, weathering or distress of facade components.
• Perform sounding of the facade surface with a hammer if material delamination of the facade components is possible by pushing against and/or pulling on facade elements.
• A pull test on adhesively-attached components at building corners and in the field of the wall should be performed.
• Probing (exterior and/or interior) is useful to observe concealed facade components such as anchors, inserts or support of facade components.
• Removing loose or fractured components to reveal the cause of distress, where safe to do so, and sampling of material obtained from probes for visual examination and laboratory testing is required.

Inspections

Whether a general or detailed inspection is needed depends on the severity of the problems and the owner's intent. A general inspection is often helpful for narrowing down possible root causes and is especially useful in situations with a short-term owner or with an owner who doesn't plan to make a significant investment in repair. In fact, a general inspection may reveal the wall system type and whether a relatively simple solution is possible, such as recaulking the window joints.

With information gathered from drawings and an inspection, a contractor is armed with the knowledge to plan a course of action. Most often, a solution involves re-pointing, wall stabilization, flashing replacement or installation of new expansion joints. An alternate, and less costly, repair may be to paint the brick. The theory is that the water-managed wall design is abandoned and a barrier wall is created with the coating, which will prevent any water penetration. However, since painting changes a building's appearance, this solution doesn't appeal to every owner. Also, when considering painting the building, it is important to ensure the solution isn't going to trap moisture and create corrosion within the steel components, especially with steel that is already beginning to rust.

The longest-lasting repair solution usually involves removing the brick, exposing the flashing, repairing or replacing the flashing, and placing the brick back into the building. This solution is usually best for an owner who intends to own the building for many years.

Considerations for Historical Repair

Masonry repair on structures built prior to 1920 require a high level of expertise. As with a contemporary repair project, the process for masonry repair on a historical building begins with fact-finding. The contractor must perform either a general or detailed inspection to search for the root causes of the masonry problem. With historic projects, it's important to know the maintenance, cleaning or waterproofing efforts that have been applied to the building. This structure specific background information regarding previous maintenance work enables a contractor to understand the repair history and plan new repairs accordingly.

Common Misconceptions: When it comes to historic masonry repair, misconceptions often arise from contractors who lack experience with the complexities of historic structures. For example, when working with a historic mortar a contractor must identify the type used. If the mortar is a cement, lime and sand mixture, a contractor must know the correct ratio of each material in order to use the same strength and make a correct match in color and texture. Another mortar, such as lime putty, may have been used. Identifying which mortar was used is crucial as taking a "one-mortar-fits-all" approach will produce damage to the historic fabric of the structure.

Another misconception involves cracking. Historic structures often exhibit extensive cracking and it is often thought that it arises from the building moving or settling. However, this sort of cracking comes from another source: embedded steel. In historic structures with masonry-clad steel frames, rusting and expanding steel causes the cracks. These cracks are often caulked, but that solution is just a patch for a more serious problem.

It is also often thought that old brick buildings will remain solid and sturdy forever, requiring little or no maintenance. However, the life expectancy for most mortars is up to 75 years. At the end of its life-cycle, mortar will require repair before moisture and water infiltration create damage to the interior of the building.

Repair Processes: Common solutions for historic projects involve pointing the building, individual brick replacement and, at times, wall rebuilding if severe damage has occurred. When embedded steel has begun to corrode, a contractor must remove the masonry, prep and paint the steel, and place the masonry back into the structure. Repairing the symptom (i.e., pointing, caulking selective brick replacement) where embedded steel corrosion is occurring without taking care of the root cause of corrosion is a decision related to the owner's intended length of possession. Another consideration is where the cracking is located. Is it over an entryway or over a public space? If so, it presents a life safety issue to people entering and exiting the structure and therefore should be repaired with a long-term solution, such as stripping the façade to expose the imbedded steel, treating the corrosion and rebuilding.

Whether an owner has a contemporary or historic project to consider, the important step is taking action against the root cause of the masonry problems. Annual inspections can reveal issues that demand attention. And, by maintaining a structure's masonry, owners will enjoy the benefits such as durability, energy efficiency and weather resistance for years to come.

About the Authors:

Mark K. Howell is a Project Development Manager with Structural Preservation Systems. He is a recognized leader in concrete and masonry maintenance repair and has been involved personally in the restoration of many historic structures during the last decade. With a degree in civil engineering and construction management technologies, Howell is a member of the International Concrete Repair Institute (ICRI), ASTM International's E6 Committee, the Sealant Waterproofing Restoration (SWR) Institute, and the Exterior Design Institute. He can be contacted via e-mail at mhowell@structural.net.

Adrienne DeRan is a Project Engineer with Structural Preservation Systems. She is a graduate of Tulane University and has worked on a variety of structures from National Historic Landmarks and federal buildings to resort hotels and adaptive reuse projects. DeRan is involved with the Preservation Trades Network (PTN) and was recently nominated for the PTN Board of Directors. She can be reached at aderan@structural.net.