When you own a home built in the late 1800s, every repair carries the weight of history. This is especially true for the brickwork, where the original materials often came from local brickyards that closed a century ago. In Episode 9 of the Ask This Old House Podcast, mason Mark McCullough tackles exactly this challenge: repairing rare brick in a historic home constructed in 1896. His approach offers valuable lessons for anyone working with historic masonry, from identifying period-appropriate materials to executing repairs that blend seamlessly with original work. If you are tackling a similar project, our collection of key building tips from podcast episode 116 provides additional context on working with older structures.
Why Historic Brick Is So Difficult to Match
Brick manufacturing in the late 19th century was nothing like modern production. Each brickyard produced bricks with unique characteristics based on the local clay deposits, firing methods, and forming techniques. This means that finding an exact match for brick from an 1896 home is rarely as simple as buying whatever the local supplier has in stock. Mark McCullough explains that homeowners and masons must first understand what made those original bricks special before attempting any repair work.
The Three Dimensions of Brick Variation
Historic bricks vary across three primary dimensions that all matter during a restoration project:
- Size — Before standardization in the early 20th century, brick sizes varied significantly between manufacturers. An 1896 brick might measure 8 1/4 inches long by 4 inches wide by 2 1/4 inches thick, while modern modular bricks come in at 7 5/8 by 3 5/8 by 2 1/4 inches. That half-inch difference per brick adds up across an entire wall and changes the look of the mortar joints considerably.
- Color — Historic bricks display a much wider color range than modern equivalents. The iron content in local clay, the temperature zones inside wood-fired kilns, and even the position of each brick in the kiln created subtle variations from pink and salmon through deep red and purple. Modern extrusion processes tend to produce far more uniform color, which can look jarring next to original brick.
- Texture — Hand-molded bricks often have a distinct surface texture, including small indentations, sand coatings from the mold release, and irregular edges. These surface features contribute to the character of historic masonry and are difficult to replicate with modern machine-made brick.
McCullough emphasizes that taking the time to analyze all three dimensions before sourcing replacement brick is essential. He recommends collecting samples from inconspicuous areas of the home, measuring them precisely, and photographing them in natural light to establish a baseline for matching. A related project featured in Episode 8 of the Carolina Comeback series demonstrates similar restoration principles applied to a different historic structure.
Finding and Selecting Replacement Brick
Once you understand what you are working with, the next step is sourcing replacement material. McCullough discusses several strategies that professional masons use to locate brick that will blend well with original 1890s work. The approach depends heavily on the extent of the damage and how visible the repairs will be.
Salvage Yards and Architectural Recovery
The most reliable source for matching historic brick is salvaged material from buildings of the same era. Architectural salvage yards across the country stock brick from demolished structures, often sorted by region and period. When visiting a salvage yard, bring a sample of your original brick along with detailed measurements. Look for brick that matches not just the color but also the hardness and porosity, since these affect how the brick interacts with mortar and weather over time.
Online marketplaces and local demolition companies can also yield good results, but you must inspect the brick in person before purchasing. Photographs can be misleading, especially for color matching, and do not convey the texture or density of the material at all.
Custom Brick Manufacturing
For large-scale restoration projects where salvaged brick is insufficient, some specialty manufacturers offer custom brick runs. These are expensive and require a significant lead time, but they can produce brick that closely matches the originals when provided with accurate samples and specifications. A custom run allows you to control the clay composition, firing temperature, and final dimensions, giving you the best possible match for large visible areas. This approach is most practical when you need more than a few hundred bricks.
Brick Selection Table
| Sourcing Method | Best For | Lead Time | Cost per Brick | Match Quality |
|---|---|---|---|---|
| Architectural salvage | Small patches, visible repairs | 1-2 weeks | $1-$3 | Excellent when well-sorted |
| Custom manufacturing | Large walls, full facades | 8-16 weeks | $5-$15 | Very good with proper samples |
| Modern commercial brick | Hidden areas, structural repairs | Immediate | $0.50-$1 | Poor for visible historic work |
| Online classifieds | Small quantities, budget projects | Variable | $0.50-$2 | Variable — inspect in person |
The right sourcing strategy depends on the visibility of the repair and the quantity of brick needed. For a single damaged brick on a front facade, salvaged material is always preferable. For a large rear wall that will eventually be covered, modern brick may be an acceptable compromise.
Mortar Matching: The Invisible Art
Mark McCullough stresses that matching the brick is only half the battle. The mortar used in historic homes is fundamentally different from modern masonry cement, and getting it wrong can ruin the appearance of even the best brick match. Mortar matching involves both composition and color, and each plays a critical role in the final result.
Lime-Based vs. Portland Cement Mortar
Most historic homes built before 1920 used lime-based mortar, which is softer and more porous than modern Portland cement mixes. Lime mortar allows brick walls to breathe, letting moisture evaporate naturally rather than trapping it inside the wall assembly. When modern cement mortar is used to repoint historic brickwork, it creates a hard, impermeable layer that forces moisture to migrate through the brick itself, causing spalling and premature failure.
For the 1896 home McCullough discusses, a Type N or Type O lime mortar with a low compressive strength is appropriate. These mortars accommodate the natural movement of historic walls and protect the softer historic brick from damage. A simple test involves rubbing a small amount of the original mortar between your fingers: if it crumbles easily, it is almost certainly a lime-based mix that should be replaced with a similar product.
Color Matching Mortar Joints
Mortar color matching is a skill that experienced masons develop over years of practice. The color of mortar is determined by the sand used, the cement type, and any added pigments. Historic mortar often has a distinct warm tone from natural sand rather than the stark gray of modern mixes.
- Collect a mortar sample from an interior joint or hidden area, at least the size of a golf ball.
- Crush the sample and examine the sand grains under a magnifying glass to determine their natural color and particle size.
- Create test batches of mortar and let them cure for at least seven days before evaluating color match, since mortar lightens significantly as it dries.
- Apply test patches to an inconspicuous area and observe them in different lighting conditions over several days.
McCullough recommends keeping detailed records of your mortar mix proportions so that future repairs can be matched consistently. This is where professionals differ from enthusiastic amateurs: the best historic restorations document every material decision for the benefit of the next generation of caretakers. If you are interested in the broader philosophy of documenting restoration work, Dirt To Done Episode 3 offers valuable insights on tracking material choices through a building’s lifecycle.
Repair Techniques That Preserve Historic Integrity
The actual process of removing and replacing damaged brick requires patience and precision. McCullough walks through the steps that a professional mason follows to ensure the repair is structurally sound while remaining visually undetectable. Rushing this process is the most common mistake homeowners make, and it leads to repairs that stand out for all the wrong reasons.
Removing Damaged Brick Without Collateral Damage
When a single brick needs replacement, the goal is to remove it without damaging the surrounding brick or disturbing the wall assembly. McCullough recommends the following sequence:
- Drill a series of holes into the mortar surrounding the damaged brick, using a masonry bit sized to match the joint width. This weakens the mortar without applying pressure to adjacent bricks.
- Use a narrow masonry chisel to carefully remove the remaining mortar, working from the center of the joint outward. Never lever against adjacent bricks.
- Once the brick is free of mortar on all sides, gently tap it from the face inward using a hammer and a wood block. The brick should slide out of the opening without force.
- Clean the cavity of debris and dust using a brush or compressed air. The surface must be clean for the new mortar to bond properly.
Installing the Replacement Brick
Installing the new brick is a deliberate process that prioritizes bond strength and visual integration:
- Butter the top and sides of the replacement brick with fresh mortar, leaving the face clean. The mortar should be stiff enough to hold the brick in place without sagging.
- Slide the brick into the cavity with a slight twisting motion to ensure even mortar contact on all surfaces.
- Tap the brick into position using a rubber mallet and a level, checking that the face is flush with the surrounding brick. Slight recessing is easier to correct than protrusion.
- Tool the mortar joints to match the existing profile, whether that is concave, V-shaped, or flush. The mortar should be tooled when it is thumbprint-hard, which typically occurs 30 to 60 minutes after application depending on temperature and humidity.
- Clean any mortar smears from the brick face immediately using a dry brush, never with acid or wire brushes, which can permanently damage the brick surface.
Long-Term Maintenance and Monitoring
After completing a brick repair, ongoing observation ensures the work holds up over time. McCullough advises checking repaired areas after the first freeze-thaw cycle and again after one full year. Signs of trouble include cracking at the brick-mortar interface, efflorescence (white salt deposits), or any shifting in the brick position. Catching these issues early allows for minor corrections rather than major rework.
Water management is also critical for preserving historic masonry. Ensure that gutters and downspouts direct water away from brick walls, that grade slopes away from the foundation, and that there are no leaking pipes inside the walls. Brick is porous by nature, but keeping bulk water off the wall surface dramatically extends the life of both the brick and the mortar. Proper maintenance, combined with careful material selection and patient execution, allows historic brick homes to stand for another century or more.