How Brick Walls Are Built

Overview

Brick walls look permanent because brick is durable, fire resistant, and familiar. What many homeowners do not realize is that most brick on modern houses is brick veneer, not a solid structural wall. The visible brick is only one part of the system. Behind it are support ledges, wall ties, drainage space, flashing, and weeps. If any of those parts are wrong, the wall may trap water, crack, or separate from the house.

Understanding how a brick wall is built helps homeowners evaluate bids, recognize poor workmanship, and avoid cosmetic repairs that ignore the real cause. Brick failures are often slow. A wall can look acceptable for years while hidden moisture damage develops behind it.

Key Concepts

Brick Veneer vs. Solid Masonry

Most houses use brick veneer attached to a framed wall. Older buildings may use structural masonry. The construction method changes how loads are carried and how repairs should be approached.

Brick Handles Water but Does Not Stop It

Brick absorbs rainwater. A proper wall assumes some water will get through and provides a path for drainage.

Movement Must Be Accommodated

Brick expands and contracts differently than wood framing and concrete. Control joints, shelf angles, and flexible ties help manage movement.

Core Content

Foundation and Support

A brick veneer wall starts with support. The brick usually sits on a concrete ledge or foundation shelf designed to carry the veneer load. That support must be level, properly sized, and positioned so the veneer aligns with the wall above. If the ledge is undersized or out of plane, the mason may compensate with poor mortar practices that create long term weakness.

This is an area where homeowner oversight matters. If the veneer support was never designed for the added load, later veneer installation can become a structural and moisture problem at the same time.

Backup Wall and Water Resistive Layer

Behind the brick is a backup wall, often wood framing with sheathing and a water resistive barrier. This hidden layer is critical. Brick is the outer skin. The backup wall is what protects the house. If flashing, wrap lapping, or penetrations are wrong, bulk water can move into sheathing and framing even if the brick itself looks fine.

The drainage cavity between brick and backup wall should be kept reasonably clear. Mortar droppings that bridge the cavity can create a path for moisture to move inward instead of down and out.

Brick Ties and Anchorage

Brick veneer is anchored back to the framing or structural wall with corrosion resistant ties. These ties keep the veneer stable while allowing limited movement. Missing ties, wrong spacing, or badly embedded ties are serious workmanship defects. They may not be visible after completion, which is why good inspection records matter.

If a contractor cannot show tie spacing requirements or inspection procedures, that is a meaningful warning sign. Veneer separation is expensive and dangerous to repair after the wall is finished.

Flashing and Weep Holes

Flashing is installed where water is expected to collect, such as above windows and doors, at the base of the wall, and at other interruptions. Weep holes allow that water to exit. Homeowners often think weeps are defects because they look like open joints. They are not defects. They are necessary drainage points.

Trouble starts when weeps are missing, blocked with mortar, buried below grade, or painted shut. Flashing also has to direct water outward. If it ends inside the wall or is punctured by careless fastening, the whole drainage strategy breaks down.

Mortar Joints and Workmanship

Mortar bonds the brick courses and influences water shedding. Joint tooling, mortar type, and bedding consistency all affect performance. Mortar joints that are recessed too deeply or left rough can take on more water. Poorly packed head joints can leak. Homeowners should not judge workmanship only by whether the wall is straight from across the street. Close inspection matters.

Color consistency is less important than sound bond, proper alignment, and effective weather detailing. A beautiful wall with failed flashing is still a failed wall.

Cracking and Movement

Brick cracks for many reasons. Small mortar cracks may reflect shrinkage or mild settlement. Step cracking, separation at corners, bulging, or lintel movement deserve closer investigation. Differential foundation movement, steel lintel corrosion, missing expansion provisions, and water intrusion are common causes.

Cosmetic repointing is not enough if the crack is being driven by movement. Homeowners should ask what caused the crack, not just how it will be filled.

Payment and Inspection Protection

The safest time to inspect a brick wall is before it is fully closed in and before final payment. Confirm flashing locations, tie installation, weep placement, clearances above grade, and lintel treatment. Require closeout photos if details will be concealed quickly. Once the wall is finished, the leverage shifts to the contractor and the hidden defects are yours to prove.

State-Specific Notes

Brick performance varies by region. Freeze-thaw climates demand more attention to moisture drainage and mortar durability. Seismic regions may have stricter requirements for veneer anchorage. Coastal areas raise corrosion concerns for ties and lintels. Local code also affects cavity width, flashing details, and veneer support design. Homeowners should expect local engineering and inspection practices to shape the final assembly.

Key Takeaways

Most residential brick walls are veneers that depend on hidden support, drainage, and anchorage details.

Brick is not waterproof. Flashing, weeps, and a protected backup wall are what keep the house dry.

Homeowners should inspect concealed work before final payment, especially ties, flashings, and clearances above grade.

A straight wall is not enough. Good masonry is as much about moisture control and movement management as appearance.