Why Do Brick Commercial Buildings Leak? Understanding Brick Veneer and Water Management

Brick leaks are a good way to get a building owner’s attention. It also makes the problem sound worse than it is. Brick has been used successfully for thousands of years. The problem is not that modern brick veneer gets wet. The key question is whether water behind the brick has a clear path back outside.

That is where many commercial brick-wall problems begin.

Does Water Really Get Behind Brick Veneer?

Water can move through or behind brick veneer, but that isn't automatically a sign the wall has failed.

Modern brick veneer walls are different from older full-masonry walls. The exterior brick is part of a larger wall assembly designed to manage water after it gets behind the veneer.

That wall assembly may include:

• drainage space
• flashing
• a water-resistive barrier
• weep openings
• window and door details
• roof-to-wall transitions
• properly detailed penetrations

The brick is important, but it is still only one part of the cladding system. The same systemthinking applies to other exterior finishes, including stucco for commercial buildings. 

Where Do Brick Buildings Commonly Leak?

Brick-wall leaks often develop around openings, transitions, and penetrations where the wall assembly is interrupted.

Buildings need windows, doors, vents, utility penetrations, cables, roof connections, and other openings. Each one creates another location where flashing, drainage, and other water-management components need to work together.

Potential problem areas include:

• window openings
• doors
• roof-to-wall intersections
• vents
• utility penetrations
• cable entrances
• ledges
• material transitions

For a commercial property with repeated leakage, the pattern can provide useful information.

Does the water appear only during certain storms? Is it limited to one elevation? Does it occur around windows? Does it show up only after prolonged rainfall?

Those details can help narrow the apparent water path and may be more useful than simply knowing that the brick is wet.

What Is a Bridge Behind Brick Veneer?

A bridge behind brick veneer creates a path that can allow water to move across the drainage space toward the interior of the wall.

Mortar buildup is one common example. During construction, mortar can collect on brick ties, ledges, or other areas behind the veneer. Enough buildup can partially block the drainage space.

That can create two problems. Water may have difficulty reaching the intended drainage point, and the buildup may also create a path toward materials farther inside the wall. The same condition can act like a small dam.

If water can't get to the weep opening, it has to find somewhere else to go.

And that "somewhere else" may be inside the building.

Bridges can also occur around windows, doors, vents, and other penetrations when the wall

components are not properly integrated.

What Do Flashing and Weeps Actually Do?

Flashing collects and redirects water, while weeps give it a path back to the exterior. The concept is straightforward, but commercial buildings can include long runs of flashing, multiple floors, repeated window openings, shelf angles, structural transitions, and penetrations.

A detail that appears once on a small building may be repeated hundreds of times on a larger one. That means a small recurring condition can become a much larger building-wide problem.

This is one reason repetitive details deserve attention during design and construction.

Why Do Repeated Brick Repairs Sometimes Miss the Problem?

Repeated brick repairs can miss the problem when the visible masonry is replaced, but the water path behind the wall remains unchanged.

If the owner authorizes brick replacement but the underlying condition involves flashing, drainage, bridges, or an opening detail, the exterior may look repaired. At the same time, the source of the water intrusion remains.

Opening the wall can provide useful information about:

• where water may be collecting
• whether drainage space is blocked
• how flashing is arranged
• whether penetrations interrupt the system
• whether other materials have been affected

For commercial buildings , that information can help distinguish between another surface repair and work that addresses the apparent source of the problem. The goal is not simply to replace what looks damaged. It is to understand what needs to change before closing the wall again.

What Should Architects and Contractors Watch for with Brick Leaks?

Architects, engineers, and contractors should pay particular attention to exposed wall conditions, repetitive details, and transitions that affect how water moves through the assembly.

For architects and engineers, observed field conditions can show how the installed assembly relates to the design intent and available project documents.

For contractors, sequencing matters because some of the most useful conditions may be visible only for a limited time period before the work is concealed.

That makes communication and timing important. A site visit while flashing, drainage space, or other components are exposed can provide more useful information than a visit after the wall is complete.

The $64,000 question is: How do you know you'll get a proper wall system the second time around?

For new construction or major repairs, make sure the architect designs and the masonry contractor constructs proper flashing, horizontal and vertical expansion joints, and other details needed to manage water.

With brick veneer, a representative wall section can help the team see how different components come together around:

• windows
• flashing
• weeps
• transitions
• expansion joints
• penetrations

The mock-up should be tested, and photographs should be taken at each stage of the successful construction. Once the wall is closed, those details are no longer visible. Good photographs can provide a kind of “comic book” record of how the wall was actually constructed and can be much easier to understand than trying to explain the construction later.

The goal is to identify and correct problems before the same detail is repeated hundreds of times across the building.

Is Brick Bad for Commercial Buildings?

Brick is not inherently bad for commercial buildings, but it needs to function as part of a wall system that manages water effectively.

Brick can be attractive, durable, and relatively low maintenance. The problem is not that brick can get wet. The problem begins when water gets behind the brick and has no clear path back outside.

That is why the owner did not simply buy brick. The owner bought a wall system.

When that wall leaks, the most useful evaluation explains how water moves through the system and what conditions may be contributing to the problem. Once the owner better understands the issue, they have better information to decide what to repair and why.

How Does Wynn L. White Consulting Engineers Help With Brick Water Intrusion?

Wynn L. White Consulting Engineers helps commercial owners, architects, and contractors evaluate water intrusion by looking beyond visible masonry and considering how the wall assembly manages water.

Work can include site visits to observe existing conditions, review available drawings and repair information, evaluate apparent water paths, and develop repair recommendations based on observed conditions.

When portions of a wall are opened during repair or construction, Wynn L. White Consulting Engineers can also conduct site visits to become familiar with the work's progress and review exposed conditions for general conformance with the design intent.

If you have a commercial building with recurring brick leaks, or you're planning new construction or a major brick repair project, we'd be happy to talk through what you're seeing.