Cutting brick for a door opening is one of those construction tasks that looks intimidating until you understand the underlying principle: a brick veneer wall and the wood frame behind it are two separate structural systems. Once you grasp that distinction, the entire process becomes a matter of careful planning, the right tools, and patience. Whether you are relocating a garage door, adding a new entryway, or enlarging an existing opening, the approach is the same. The wood frame carries the roof and floor loads, while a steel lintel supports the brick above the new opening. This guide walks you through every step, from assessing the existing wall to laying the final brick course above the lintel. For more background on how brick veneer interacts with framing, see our detailed overview of brick construction techniques for modern homes.
Understanding Brick Veneer and Structural Framing
Before you make any cuts or remove any bricks, you need to understand how a brick veneer wall is built. In most residential construction, the brick is not load-bearing. It is a single wythe (one layer thick) that is attached to the exterior of a wood or steel frame. The wood studs, top plate, and floor joists carry the vertical loads of the roof and upper floors. The brick veneer supports only itself, and even then, it relies on a steel lintel whenever there is an opening beneath it.
How the Two Systems Work Together
Brick veneer is connected to the framing with corrosion-resistant wall ties, typically installed every 16 inches vertically and every 24 inches horizontally. A one-inch air gap separates the brick from the sheathing, allowing moisture to drain and air to circulate. When you cut an opening in this assembly, the following happens:
- The wood framing is cut and reframed to create a rough opening for the door or window.
- The brick veneer above the opening is supported entirely by a steel lintel that spans the width of the opening.
- The lintel transfers the brick load to the brick piers on either side of the opening, not to the wood frame.
- Flashing and weep holes are installed to direct any moisture that penetrates the brick back to the exterior.
This separation of duties is why the wood frame can be cut and reframed without concern for the brick above, provided the lintel is sized and installed correctly.
When You Need a Lintel
Any opening in a brick veneer wall wider than one brick (about 8 inches) requires a steel lintel. For garage doors, which can be 8, 9, or even 16 feet wide, the lintel must be sized by an engineer or sized generously to account for the span and the number of brick courses above. A common rule of thumb is that the lintel should bear at least 4 inches on each side into the existing brickwork. The table below provides typical lintel sizes for common garage door widths.
| Garage Door Width | Recommended Lintel Size | Minimum Bearing | Typical Brick Courses Above |
|---|---|---|---|
| 8 ft (2.44 m) | L4 x 3.5 x 3/8 in. | 4 in. | 6 to 10 |
| 9 ft (2.74 m) | L5 x 3.5 x 3/8 in. | 4 in. | 6 to 10 |
| 16 ft (4.88 m) | L6 x 4 x 3/8 in. or W-section | 5 in. | 4 to 8 |
| 18 ft (5.49 m) | Engineered W-section | 6 in. | 4 to 6 |
The steel lintel should be painted with a rust-inhibitive coating and wrapped with flashing that extends up behind the building paper or weather-resistant barrier on the wall above.
Preparing the Wall: Removing Brick and Reframing
Preparation is the phase where careful measurement and methodical work pay off. Rushing this stage leads to chipped brick, uneven openings, and unnecessary repairs. Before cutting, ensure the garage roof is properly supported. A hip-roof garage distributes loads differently than a gable roof, so consult a structural engineer or experienced contractor if you are unsure about temporary shoring. For a thorough discussion of garage construction considerations, read our article on designing garages with living space above, which covers structural coordination in detail.
Cutting the Mortar Joints
Use a circular saw equipped with a diamond or abrasive masonry blade to cut the mortar joints. You do not need to cut through the brick itself. The goal is to separate the brick along the mortar lines. Cut the vertical head joints and the horizontal bed joints in a toothed or staggered pattern, as shown in the diagram below. This staggered approach prevents a continuous vertical crack line from forming.
Follow these steps for the cutting phase:
- Mark the rough opening dimensions on the brick face, adding 8 to 12 inches beyond each side of the door frame.
- Cut the mortar joints with the circular saw set to the depth of the mortar joint (typically 3/8 to 1/2 inch).
- Use a hammer and brick set (a wide cold chisel) to break any remaining mortar bridges.
- Remove bricks individually, starting from the top of the wall and working down. Do not try to save the bricks above the opening; removal is easier in reverse order.
- Cut the wall ties with an angle grinder or bolt cutters as you expose them.
Reframing the Rough Opening
Once the brick is removed and the sheathing is exposed, you can cut the wood framing. Install a temporary header and support the ceiling joists or rafters with adjustable jack posts. Then remove the existing studs and install a new header sized for the door opening. The header should be double 2x12s or an engineered beam, depending on the span and load. Fasten the new king studs and jack studs with 16d nails or structural screws. Remember that the wood opening is typically 1/2 to 3/4 inch larger than the door frame on each side to allow for shimming and adjustment.
Installing Brick Molding and Weatherstripping
After the door frame is installed and shimmed plumb and level, attach the brick molding around the perimeter. Use self-adhering foam weatherstripping tape along the outside face of the brick molding. This tape maintains a consistent gap for the caulk joint between the brick molding and the brickwork that will be reinstalled later. The gap should be about 3/8 inch wide to allow for thermal expansion and to provide a clean caulk line.
Installing the Lintel and Flashing
The lintel and flashing assembly is the single most important part of cutting brick for a door. If the lintel is undersized, the brick above can settle, crack, or even collapse. If the flashing is incorrectly installed, water will migrate behind the brick and into the wall cavity, causing rot and mold. Take your time with this phase.
Lintel Placement and Bearing
The lintel must sit on solid brick on both sides of the opening. Cut pockets into the existing brickwork at the correct height to receive the lintel ends. Each end should bear at least 4 inches on the brick pier. For wider openings, increase the bearing to 5 or 6 inches. The lintel should be level from end to end. Use a full-length level and shim with steel shims if needed. Once the lintel is positioned and level, pack the pockets with non-shrink grout.
Key lintel installation checks:
- Lintel is level within 1/8 inch over its entire length.
- Minimum 4-inch bearing on each side.
- Lintel extends beyond the finished opening width by at least the bearing distance on each side.
- Lintel is painted or primed to resist rust before installation.
Flashing Details That Prevent Leaks
The flashing must be installed in a continuous layer that directs water outward. Use a corrosion-resistant flashing material such as copper, stainless steel, or coated aluminum. The bottom leg of the flashing should extend past the face of the brick by 1/4 to 3/8 inch and be turned down slightly to form a drip edge. The top leg of the flashing extends up behind the building paper or weather-resistant barrier by at least 6 inches. Any joints in the flashing should overlap by 6 inches and be sealed with butyl caulk or flashing tape.
For a deeper dive into the types of hand tools used in precision brickwork, see our guide on brick masonry tools and their applications.
Weep Hole Placement
Weep holes are small openings in the vertical mortar joints of the first brick course above the flashing. They allow any moisture that collects on the flashing to drain to the exterior. Space weep holes at every 24 to 33 inches along the lintel, which is approximately every third head joint for standard brick. Leave the vertical mortar joint open or insert a plastic weep tube, cotton rope wick, or proprietary weep vent. Do not seal these openings with caulk or mortar.
Laying Brick Above the Lintel
Once the lintel and flashing are in place, you are ready to rebuild the brickwork across the top of the opening. This is the phase that restores the appearance and weather resistance of the wall. Matching the existing brick, mortar color, and joint profile is essential for a seamless look.
Setting the First Course
The first course of brick above the lintel should be set directly on the flashing with no mortar under the bricks. This is intentional: the gap allows any water that penetrates the brick face to flow down to the flashing and out through the weep holes. If you mortar the first course to the lintel, water gets trapped and will migrate into the wall. Set the first course in a full bed of mortar on the back and head joints, but leave the bottom joint open against the flashing. The brick will be held in place by the mortar on the sides and the weight of the courses above.
Matching Mortar and Joint Profile
Mix a small sample batch of mortar and let it set before you begin. Compare the color and texture to the existing wall. If the match is close, proceed. If not, adjust the sand color or add a small amount of pigment. The joint profile should also match the existing wall: struck joints, concave (tooled) joints, flush joints, or raked joints each give a different appearance. A concave joint is the most weather-resistant and is the standard for exterior brickwork.
When laying brick above the lintel, build the courses slowly. Let each course set for at least 24 hours before adding the next. This prevents the fresh mortar from squeezing out under the weight of the brick above. For large openings like garage doors, you may need to build the brickwork in three or four lifts over several days.
Mortar joint types and their characteristics:
| Joint Type | Weather Resistance | Appearance | Common Use |
|---|---|---|---|
| Concave (tooled) | Excellent | Rounded, smooth | Exterior walls, most common |
| V-joint | Good | Sharp V shape | Colonial and traditional styles |
| Flush | Fair | Flat, flush with brick | Interior or sheltered walls |
| Raked | Poor | Recessed 1/4 in. | Decorative, not for wet climates |
| Struck | Good | Beveled, sloped down | Historical restoration |
Finishing the Wall and Cleanup
After the final course is laid and the mortar has set for at least 48 hours, clean the brick face with a stiff fiber brush and water. Avoid using muriatic acid unless the brick has significant mortar smears, and if you must use acid, wet the wall thoroughly first and rinse continuously. Tool all joints to the desired profile before the mortar hardens completely. Finally, inspect the weep holes to ensure they are open and clear, and caulk the gap between the brick molding and the brickwork with a high-quality polyurethane or silicone sealant. For additional guidance on door installation and finishing, review our comprehensive guide to door design and installation tips for homeowners and builders.
Common Mistakes and How to Avoid Them
Even experienced masons and carpenters can make errors when cutting brick for a door opening. The most frequent problems involve underestimating the load, improper flashing, and rushing the mortar cure. Awareness of these pitfalls saves time and prevents expensive rework.
Underestimating Brick Load Above the Opening
Brick is heavy. A standard modular brick weighs about 4.5 pounds, and a typical wall has 7 bricks per square foot. For a 16-foot garage door with 6 feet of brick above it, the lintel must support over 3,000 pounds of brick, plus the dynamic load of wind and seismic forces. Do not guess the lintel size. Have it specified by a structural engineer or use generously oversized sections. The cost of upsizing a lintel by one size is minimal compared to the cost of repairing a failed wall.
Incorrect Flashing Integration
The most common flashing mistake is failing to lap the top leg behind the building paper. Water that runs down the face of the sheathing will simply flow behind the flashing if the paper is not overlapping the flashing correctly. Always install the building paper so it laps over the top leg of the flashing, shingle-fashion. Any water then flows over the flashing and out through the weep holes. For more information on managing water in masonry structures, see our article on understanding and treating damp masonry.
Rushing the Work
Mortar needs time to gain strength. If you build more than three or four courses of brick in a day, the lower joints may squeeze out or deform under the load. Plan the brickwork so that each lift has at least 24 hours to cure. In hot weather, mist the fresh brickwork with water to slow the cure and prevent cracks. In cold weather, protect the work with insulating blankets and use mortar mixed with accelerators or hot water.
Successfully cutting brick for a door opening is a marker of skill that separates experienced builders from novices. It requires an understanding of two different structural systems working together, precision in cutting and framing, and patience in the finishing trades. The result is an opening that looks as though it was part of the original design, with the brickwork seamlessly integrated and the flashing ensuring long-term durability. For a broader view of masonry construction methods, read our overview of brick wall patterns and their structural properties.