Why Painting Brick Uses So Much More Paint—The Mortar Joint Problem and Surface Porosity
Every gallon of exterior latex paint covers 350 to 400 square feet on smooth wood or vinyl siding. That same gallon covers only 150 to 175 square feet on standard unpainted red brick. The reason is twofold. First, brick itself is a porous fired clay material with a cellular internal structure that actively absorbs liquid. Unlike wood, which resists absorption to some degree, raw brick draws paint into its pores aggressively during the first coat—often consuming two to three times what a smooth surface would require. Second, the mortar joints that fill the spaces between individual bricks are made of cement-based mortar that is even more absorbent than the brick itself. On a standard brick wall, mortar joints account for approximately 15 to 20 percent of the total surface area, and each linear inch of mortar joint surface absorbs paint faster and deeper than the brick face.
This porosity difference is why so many homeowners who try to paint a brick fireplace or exterior brick wall run out of paint partway through the first coat despite buying what seemed like an adequate quantity. They used an online calculator designed for drywall or wood siding and got a number that was less than half of what brick actually needs. Our calculator applies coverage rates specific to brick type and condition: unpainted standard brick at 150 square feet per gallon, smooth face brick at 200 sq ft/gal, and split face block (CMU) at only 100 sq ft/gal due to its dramatically rougher, more porous profile.
The condition of previously painted brick also matters significantly. Brick that was painted 10 years ago in good condition where the paint film is still intact covers at roughly 250 square feet per gallon—similar to a matte-painted wall—because the old paint has already filled the pores. But brick where the old paint is chalking, peeling, or has been partially stripped returns to semi-porous behavior and requires more paint to seal and cover. Our calculator accounts for this by applying a reduced coverage rate for chalking or deteriorated previously painted brick.
The Decision You Can Not Easily Undo—What to Know Before Painting Brick
The National Park Service preservation brief on historic masonry notes that once painted, brick is essentially a permanent commitment. Unlike wood siding where paint can be stripped relatively easily with chemical removers, removing paint from brick without damaging the surface typically requires sandblasting or high-pressure wet abrasive blasting—processes that can erode the brick face, damage mortar joints, and change the character of the masonry permanently. For historic brick homes, painting is generally discouraged by preservation guidelines precisely because of the difficulty of reversal. For newer homes or situations where the brick is already in poor condition, the aesthetics of a fresh painted finish may outweigh this concern. Make the decision with the full picture in mind.
How the Brick Paint Calculator Works
Coverage Rates by Brick Type and Condition
Unpainted standard modular brick: 150 sq ft/gal. Unpainted smooth face brick: 200 sq ft/gal. Unpainted split face block or CMU: 100 sq ft/gal. Unpainted natural stone or fieldstone: 125 sq ft/gal. Previously painted in good condition: 250 sq ft/gal (all types). Previously painted with chalking or fade: 180 sq ft/gal. Previously sealed with masonry sealer: 225 sq ft/gal. These rates reflect single-coat coverage with a roller on a standard unpainted surface, consistent with paint manufacturer published coverage data for masonry surfaces.
Masonry Primer
Masonry primer (also called block filler or masonry sealer when used as a primer) covers approximately 150 square feet per gallon on unpainted brick because it must penetrate into the pores to seal the surface before topcoat. On previously painted brick in good condition, a standard bonding primer covers 250 to 275 sq ft/gal. Our calculator uses 150 sq ft/gal for primer on raw masonry and 250 sq ft/gal on previously painted surfaces.
3 Real Brick Paint Estimates—US Homes and Projects
Example 1 — Exterior Brick Ranch Home, Richmond, VA
Scenario: The Williams family is painting their 1960s brick ranch home in Richmond. Three sides are brick (the fourth is siding); together those three brick sides measure 140 linear feet at an average height of 8 feet. The total brick area is 140 x 8 = 1,120 sq ft. Standard modular brick, never painted. Masonry primer included. Two topcoats. Paint is $52 per gallon, primer $38.
Coverage rate (unpainted standard brick): 150 sq ft/gal.
Topcoat (2 coats): 1,120 x 2 / 150 = 14.9 gallons. Buy 15 gallons.
Primer (masonry primer, raw brick at 150 sq ft/gal): 1,120 / 150 = 7.5 gallons. Buy 8 gallons.
Total: 23 gallons. Estimated cost: (14.9 x $52) + (7.5 x $38) = $775 + $285 = ~$1,060 in materials.
Note: An estimator using a standard “wall paint” coverage of 400 sq ft/gal would have calculated only 5.6 gallons—less than 40% of what this project actually requires.
Example 2 — Interior Fireplace Surround, Charlotte, NC
Scenario: Marcus wants to paint his dated 1980s red brick fireplace surround white to modernize the living room. The surround measures approximately 6 feet wide by 5 feet tall (30 sq ft) plus a raised hearth 4 feet wide by 2 feet tall (8 sq ft). Total brick area: 38 sq ft. Standard brick, never painted. Masonry primer, 2 coats. Interior masonry paint at $45 per gallon.
Coverage (unpainted standard brick, 150 sq ft/gal):
Topcoat (2 coats): 38 x 2 / 150 = 0.51 gallons. Buy 1 quart (covers with room to spare).
Primer: 38 / 150 = 0.25 gallons. Buy 1 quart of masonry primer.
Total cost: At quart pricing (~$15 per quart), approximately $30 total for materials.
This is why buying a full gallon for a fireplace project wastes most of the can. For a small brick fireplace, 2 quarts total (primer + paint) is typically sufficient for 2 topcoats on a surround under 60 sq ft.
Example 3 — Split Face CMU Retaining Wall, Phoenix, AZ
Scenario: Elena is painting a decorative split face concrete masonry unit (CMU) garden wall that borders her backyard. The wall is 45 linear feet at 4 feet tall = 180 sq ft. Both sides will be painted (inside and outside of the wall). Total area: 360 sq ft. Split face CMU is extremely rough and porous. Never painted. Exterior masonry paint at $48/gal. Primer included. 2 coats.
Coverage (unpainted split face CMU, 100 sq ft/gal):
Topcoat (2 coats): 360 x 2 / 100 = 7.2 gallons. Buy 7 gallons + 1 quart.
Primer: 360 / 100 = 3.6 gallons. Buy 4 gallons of masonry primer.
Total: 11+ gallons. Estimated cost: (7.2 x $48) + (3.6 x $38) = $346 + $137 = ~$483.
Split face CMU is the most paint-hungry masonry surface common in US residential landscaping. Its jagged, rough texture creates enormous additional surface area compared to smooth or standard brick.
3 Expert Tips for Painting Brick Successfully
⚠️ Before You Paint: The Efflorescence and Moisture Check
Efflorescence is the white, powdery salt deposit that appears on brick surfaces when moisture moves through the masonry and carries dissolved salts to the surface. Painting over efflorescence traps moisture behind the paint film, which then causes blistering, peeling, and potential structural damage as the moisture has no path to escape. Before painting any brick—especially on basement walls, garden walls, or ground-level exterior brick—check for efflorescence by looking for white streaks or crusty deposits. If present, identify and fix the moisture source first, then remove the efflorescence with muriatic acid solution (carefully diluted per the manufacturer’s directions, with full protective equipment), allow the brick to dry completely for 30 days, and then paint. Painting over active moisture or efflorescence will result in premature paint failure regardless of the paint quality.
✅ Tip 1: Use a Thick-Nap Roller (3/4 to 1 Inch) on Brick—Not a Short-Nap Roller
The standard 3/8-inch or 1/2-inch nap rollers used for interior walls do not reach into the mortar joints or the texture of brick faces effectively. On porous brick, a thin-nap roller will leave mortar joints unpainted and produce an uneven coverage that requires extra coats to correct. Use a 3/4-inch or 1-inch thick nap roller specifically designed for rough masonry surfaces. Load the roller generously—more paint per pass than you would for a smooth wall—and work in sections of 3 to 4 square feet. After rolling a section, use a masonry brush to work paint into the mortar joints and any areas the roller missed. This “roll and brush” technique produces the most thorough first-coat coverage and reduces the number of topcoats needed on porous brick.
✅ Tip 2: Consider Limewash as a Reversible Alternative to Standard Masonry Paint
Limewash (also called whitewash or German smear, depending on the application technique) is a historic masonry finish made from slaked lime that has experienced a dramatic design revival in the US over the past five years. Unlike standard acrylic or latex masonry paint which forms an impermeable film over the brick, limewash is absorbed into the brick pores and becomes part of the masonry. It maintains the brick’s natural breathability, which allows moisture to escape from the wall rather than being trapped behind the paint film. Limewash also produces a characteristically beautiful washed, aged appearance that standard paint cannot replicate. Most importantly, limewash can be partially or fully removed with a pressure washer and scrub brush if you change your mind—a significant advantage over standard masonry paint, which is essentially permanent. The tradeoff is durability: limewash fades more quickly than paint and typically needs refreshing every 5 to 10 years in exposed outdoor locations.
Frequently Asked Questions About Painting Brick
Is painting brick a good idea for a house exterior?▼
It depends on your goals and your brick’s condition. Painting exterior brick can dramatically change the aesthetic of a home, turning a dated red brick colonial into a crisp modern white or charcoal gray exterior. It can also protect brick that is already in poor condition—spalling, crumbling mortar joints, or heavily efflorescent surfaces that have been properly repaired can be sealed and protected by quality masonry paint. The primary disadvantage is permanence: once painted, the brick is very difficult to unpaint, and if the paint begins to fail (peeling, blistering), the repair work is substantially more complicated than repainting clean brick would be. For homes in historic preservation districts, check local regulations before painting—many jurisdictions restrict or prohibit painting original brick on historically significant structures.
How many gallons of paint do I need for a brick fireplace?▼
A standard residential fireplace surround (approximately 6 feet wide by 5 feet tall) has roughly 30 square feet of brick surface area. At the standard unpainted brick coverage rate of 150 sq ft/gal, two coats requires about 0.4 gallons of paint. Add a quart of masonry primer. Total: 2 quarts is sufficient for most single fireplace surround projects. Buy 1 quart of masonry primer and 1 quart of interior masonry paint if the project is under 60 sq ft. For a two-story floor-to-ceiling brick fireplace feature wall (sometimes 80 to 120 sq ft), step up to 1 gallon of paint and 1 quart of primer for two coats. Use our calculator above with your actual measurements for a precise number.
What is the best paint for a brick fireplace?▼
For a fireplace surround that does not get directly heated (the brick visible around the opening but not inside the firebox), a 100% acrylic interior masonry paint works well. Good options include Sherwin-Williams Masonry, Stucco and Brick Paint or BEHR Masonry, Stucco and Brick Paint. For the firebox interior (the black chamber that actually gets hot), you must use high-temperature paint specifically rated for direct heat exposure—standard masonry paint will burn, peel, or release fumes when exposed to the temperatures inside a working firebox. Rutland Hi-Temp Paint (rated to 1,200 degrees F) is the standard product for firebox interiors. Never use standard interior or masonry paint inside the firebox itself.
Can I remove paint from brick if I change my mind?▼
Removing paint from brick is extremely difficult and often impractical for large surface areas. Chemical paint strippers can soften paint for scraping but require multiple applications, generate significant toxic waste, and often leave the mortar joints heavily stained. Sandblasting is the most effective method but erodes the brick face surface, removing the weathered outer layer that gives older brick its character, and can damage or dislodge mortar joints requiring extensive repointing afterward. Media blasting (using walnut shell or corn cob media rather than sand) is gentler but still alters the brick surface. For historic brick with its fired hard outer surface (the “fire skin”), any abrasive removal method risks exposing the softer inner clay, which weathers much more rapidly. The honest answer is that for a large surface area like an exterior house wall, paint removal is so expensive and difficult that it essentially is permanent once applied.
Do I need masonry primer before painting brick?▼
Yes, masonry primer is strongly recommended before painting any brick, and it is essentially non-negotiable for unpainted brick. Masonry primer (also called block filler, masonry conditioner, or masonry sealer when used as a primer) has two functions: it penetrates the pores of the brick and mortar to seal the surface, dramatically reducing the amount of topcoat paint needed for coverage; and it provides a chemical bonding layer that improves the adhesion of topcoat paint. Unpainted brick applied with topcoat paint but no primer will require significantly more topcoat coats to achieve opacity and will have poorer adhesion over time. The primer pays for itself in reduced topcoat consumption. A quality masonry primer costs $25 to $45 per gallon and covers 100 to 150 sq ft per gallon on raw brick.
What is elastomeric masonry paint and when should I use it?▼
Elastomeric masonry paint is a thick, flexible exterior paint formulated specifically for masonry surfaces. Unlike standard acrylic paint, which is rigid when cured, elastomeric paint remains flexible and can bridge hairline cracks (typically up to 1/16 inch) that develop in stucco and masonry surfaces from thermal expansion and contraction. It is applied much more thickly than standard paint—typically with a 3/4 to 1-inch nap roller at 10 to 15 mils wet film thickness versus 3 to 4 mils for standard paint—which means it covers approximately 50 to 100 sq ft per gallon rather than the 150 to 175 of standard masonry paint. The primary use case for elastomeric paint is exterior stucco in hot climates (Arizona, California, Texas) where thermal cycling creates micro-cracks regularly, and for exterior concrete or masonry block (CMU) walls that have existing hairline cracking. It is not necessary for interior brick or for exterior brick in good structural condition.
How do I prepare brick for painting?▼
Brick prep follows a specific sequence. First, inspect all mortar joints and repair any that are crumbling, missing, or cracked with a mortar repair compound or hydraulic cement. Allow repairs to cure for at least 7 days before painting. Next, clean the brick surface thoroughly with a stiff scrub brush and a masonry cleaner or TSP solution mixed in warm water. For green mildew or black staining, use a bleach-based masonry cleaner. Rinse completely and allow to dry for at least 48 hours for interior brick and 5 to 7 days for exterior brick (brick retains moisture for extended periods). Check for efflorescence (white powder deposits) and treat with muriatic acid solution if present, following all safety precautions. Once the surface is clean and fully dry, apply masonry primer with a thick-nap roller, brush the mortar joints thoroughly, and allow primer to dry per manufacturer instructions before topcoat.
How much does it cost to paint an exterior brick house?▼
Professional exterior brick painting for a typical single-family brick home runs $3,000 to $9,000 depending on the size of the house, the condition of the brick, and the number of stories. The high labor cost compared to painting siding reflects the intensive prep required (mortar repair, cleaning, efflorescence treatment), the thick-nap roller work needed for proper coverage, the additional primer coats required, and the brush work needed to reach mortar joints. Material costs for a typical 1,200 to 1,500 sq ft of exterior brick area run $700 to $1,400 for primer and two topcoats using quality masonry paint. DIY brick painting is feasible for single-story homes and smaller brick surfaces but becomes significantly more challenging on two-story homes where scaffold or extension ladder work is required for the upper sections and gable areas.
Can I use a sprayer to paint brick?▼
Sprayers work well for applying primer and the first coat on exterior brick because the high pressure drives paint into the pores and mortar joints more effectively than rolling alone. However, spraying must always be followed immediately by back-rolling—using a thick-nap roller to distribute the wet sprayed paint evenly and ensure it penetrates the texture rather than building up on the peaks. Spraying without back-rolling on brick often produces inadequate coverage in the mortar joints and low spots of the texture. For interior brick (fireplace, accent walls), rolling and brushing is the most practical approach since a sprayer in an interior space requires extensive masking of surrounding surfaces and ventilation of overspray. For small areas under 50 sq ft, brush and roller is always the most controllable and efficient method regardless of the surface.
How long does painted brick last before needing repainting?▼
Exterior painted brick done with proper prep and quality 100% acrylic masonry paint typically lasts 7 to 12 years before noticeable fading, chalking, or peeling require repainting. Elastomeric masonry paint on exterior surfaces can last 10 to 15 years due to its thicker film build and crack-bridging flexibility. Interior painted brick (fireplaces, accent walls) essentially does not need repainting due to UV exposure since interior environments lack the UV radiation and moisture cycling that degrade exterior paint—interior brick may only need repainting if the color choice is updated. The biggest variable in exterior brick paint longevity is the quality of the initial surface prep: brick that was thoroughly cleaned, fully dried, and properly primed before topcoat will outlast hastily prepared brick by three to five years regardless of the paint product used.
What color should I paint my brick?▼
White and off-white remain the most popular painted brick colors in the US because they brighten exteriors dramatically, create classic American curb appeal, and reflect heat in warm climates. The most popular painted brick whites include Benjamin Moore White Dove, Sherwin-Williams Alabaster, and Benjamin Moore Chantilly Lace. Deep charcoal gray (Sherwin-Williams Iron Ore or Benjamin Moore Wrought Iron) has grown rapidly as a dramatic alternative, particularly for modern or transitional-style homes. For interior brick fireplaces, pure white (Benjamin Moore Chantilly Lace or Sherwin-Williams Extra White) is the overwhelming choice for homeowners updating dated red brick surrounds. Black fireplaces (Sherwin-Williams Black Magic or similar) create a striking fireplace feature that has gained substantial popularity in recent years. Avoid very dark colors on exterior brick in hot climates—dark painted brick absorbs significantly more solar heat than natural red brick.
Is limewash paint a good option for brick?▼
Limewash is an excellent option for brick when you want a European washed, aged appearance rather than a crisp painted look, and particularly when you want a finish that maintains the brick’s breathability and is theoretically reversible. Limewash is a mineral-based finish derived from slaked lime that is absorbed into the brick rather than forming a film on top of it. This allows moisture vapor to pass through the brick wall rather than being trapped, which is important for older homes with solid masonry walls without a modern vapor barrier. It creates a characteristic mottled, semi-transparent appearance where the texture and color of the brick show through the white wash—it cannot be made to look as opaque and uniform as standard masonry paint. Limewash fades more quickly than acrylic masonry paint (typically needs refreshing every 5 to 10 years) but can simply be washed back with a pressure washer and reapplied rather than stripped. Portola Paints Classico Limewash and Romabio Classico Limewash are the most widely available quality products in the US market.
Can I paint only part of my brick house?▼
Painting only part of an exterior brick house is generally not recommended for aesthetic reasons, though it is technically possible. A house that is half painted brick and half unpainted brick will look unfinished or as if the project ran out of money. However, there are valid applications for partial brick painting: painting only the interior fireplace surround while leaving exterior brick natural; painting a foundation wall while leaving the main siding unpainted; or painting accent brick details (like a chimney breast or entry arch) a contrasting color while leaving the field brick in its natural state. For any partial painting project, mask and edge carefully along the transition between painted and unpainted areas, and be aware that the paint edge will be visible and permanent.
What causes painted brick to peel?▼
Peeling painted brick almost always comes down to one of three causes. The first and most common is moisture trapped behind the paint film. If the brick had moisture infiltration from a roof leak, rising damp from grade, or condensation from interior humidity differences, the moisture vapor trying to escape pushes the paint film away from the brick surface in blisters that then peel. The second cause is inadequate surface prep—painting over dirty, efflorescent, or wet brick prevents proper paint adhesion and the paint separates from the masonry rather than bonding to it. The third cause is using interior paint on an exterior application, which lacks the flexibility and UV resistance to survive the thermal cycling and moisture exposure of an outdoor environment. All three causes are preventable: fix moisture sources before painting, prep the surface thoroughly, and use a quality exterior masonry paint with a compatible masonry primer.
How do I paint brick mortar joints?▼
Mortar joints require deliberate attention during brick painting because they are recessed relative to the brick face and therefore not efficiently covered by a roller passing over the surface. After rolling a section of brick, use a 2 to 3-inch masonry brush (also called a stippling brush) to dab and work paint into the mortar joints before the roller coat dries. Work systematically: roll a 3 to 4-square-foot section, then immediately brush the mortar joints within that section, then move to the next section. The brush dabbing action forces paint into the recessed mortar surface far more effectively than the roller can. Skipping this step results in visible gray mortar joints showing through the painted brick faces—a result that looks amateurish and requires an additional full roller coat to correct.
What is German smear and how does it differ from painting brick?▼
German smear (sometimes called mortar wash) is a technique where a thin mixture of Portland cement-based mortar is smeared over the brick surface with a brush or gloved hand and then partially wiped or scrubbed off while still wet, leaving a rough, rustic coating that adheres to the brick but leaves some of the original brick texture and color peeking through. It creates a heavily textured European farmhouse appearance that standard paint cannot replicate. German smear is more durable than limewash but less reversible—the mortar bonds strongly to the brick and cannot be pressure washed off. Unlike paint, which sits on top of the brick as a film, German smear is itself a masonry material that becomes part of the wall. It requires no primer and no topcoat. German smear is applied to dry, clean brick—wetting the brick slightly before application helps prevent the mortar from drying too fast in hot conditions. It is a DIY-friendly technique for achieving a high-end aesthetic at relatively low material cost.
Related Paint & Masonry Calculators
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Editorial Standards & Legal Disclaimer
Coverage rates in the Brick Paint Calculator are based on paint manufacturer published data for masonry surfaces. Standard modular brick coverage is 150 sq ft/gal unpainted, following published rates from Sherwin-Williams, Benjamin Moore, and BEHR masonry paint product data sheets. Split face CMU rate of 100 sq ft/gal reflects BEHR and QUIKRETE block filler documentation. Previously painted brick coverage of 250 sq ft/gal reflects reduced porosity of sealed surfaces. The National Park Service preservation guidance reference is sourced from NPS.gov. All coverage rates are estimates; actual results vary by application method, surface texture, and specific product. Masonry painting is potentially permanent—consult local historic preservation guidelines before painting brick on historic structures. Last reviewed: August 2026.