Exposed brick walls in commercial spaces are genuinely beautiful, but they're also one of the most demanding surfaces to paint well. The rough, porous texture, the mortar joints, the tendency to trap moisture and shed efflorescence: each of these creates a failure point that smooth plaster simply doesn't have. Apex Painters Melbourne handles exposed brick regularly across Melbourne offices, retail fit-outs, hospitality venues and heritage buildings, and the approach differs significantly from standard interior wall painting.
Why exposed brick behaves differently to other commercial surfaces
Brick is alkaline, absorptive and dimensionally variable. Two bricks side by side can have meaningfully different porosity, which means paint soaks in unevenly and produces a patchy result unless the right primer is applied first. Mortar joints add a second texture and a second substrate in the same visual field, and both need to hold paint without cracking or peeling independently.
In commercial environments, the problem compounds. High foot traffic near brick feature walls generates dust and scuff marks. Hospitality venues expose brick to cooking vapours and grease. Offices may have brick walls adjacent to air-conditioning vents that create condensation cycles. Each scenario asks something different of the paint system.
Moisture is the most common cause of failure. Brick that looks dry can still hold residual moisture behind the face, and applying a film-forming paint over wet brick traps it inside. The result is blistering, efflorescence pushing through the paint film and, eventually, large-scale delamination. Apex Painters Melbourne tests moisture content before any brick painting job proceeds.
Surface preparation: what can't be skipped
Preparation on exposed brick takes longer than on plaster. These are the steps Apex Painters Melbourne completes on every commercial brick project:
- Efflorescence removal. White salt deposits on brick must be dry-brushed off and, where heavy, treated with a dilute phosphoric acid wash before any coating is applied. Painting over efflorescence guarantees it will push back through.
- Mortar repair. Cracked or hollow mortar joints need raking out and repointing before painting. A painted joint that's cracked underneath will simply crack through the paint film within months.
- Degreasing. Commercial kitchens and hospitality venues need a dedicated degreaser applied and rinsed before priming. Grease contamination is invisible on raw brick but causes instant adhesion failure.
- Dust and debris removal. A stiff brush and industrial vacuum clear loose particles that would otherwise sit under the paint film and cause pinholes.
Choosing the right primer for commercial brick
The primer decision matters more on brick than almost any other surface. A penetrating masonry sealer consolidates the porous face and creates a stable, consistent base for the topcoat. Apex Painters Melbourne uses a water-based masonry primer on most commercial brick jobs because it allows residual moisture to escape during curing rather than trapping it behind an impermeable film.
For heritage brick with heavy efflorescence history, an anti-efflorescence primer is the right call. It creates a physical barrier that salt crystals can't push through. On brick walls adjacent to expansion and control joints, the primer selection also needs to account for movement, because any rigid primer applied across a joint line will crack when the building moves.
Two coats of primer is standard for commercial brick. One coat on a highly porous surface will still leave thin spots that topcoat soaks into unevenly.
Paint product selection by environment
The environment the wall sits in drives the product choice more than the visual outcome does. Apex Painters Melbourne selects from three broad categories:
Breathable masonry paint suits offices, reception areas and retail spaces where moisture cycling is moderate. These water-based paints allow vapour transmission so that any moisture that finds its way into the brick can escape without blistering the paint film. They're available in a full range of tints and in low-sheen to semi-gloss finishes.
Epoxy-modified masonry coatings suit commercial kitchens, brewery fit-outs and food processing areas. The chemistry gives the film resistance to grease, humidity and chemical cleaning agents that standard masonry paint can't match. The trade-off is rigidity: epoxy coatings don't handle movement as well, so they're not ideal on brick that shows active cracking.
Elastomeric masonry coatings suit external or semi-external commercial walls, and interior brick walls in buildings with known movement. The rubber-like film bridges hairline cracks and accommodates minor substrate movement without splitting. Apex Painters Melbourne uses elastomeric coatings on older Melbourne commercial buildings where brick mortar has some age-related flex.
Sheen level and the commercial context
Sheen choice on brick is partly aesthetic and partly practical. Low sheen finishes read as more authentic: the texture of the brick reads strongly and the light scatter is soft. But low sheen is harder to clean, which matters in high-traffic commercial corridors or hospitality venues where walls take regular contact. A satin finish sits in the middle: enough sheen to wipe down, not so much that it looks like a film has been painted over the brick.
Gloss on interior commercial brick is rarely the right call. It flattens the texture visually, shows every imperfection and reads more like a coating than a finish. If you're working on high-traffic commercial walls and want durability, a satin masonry product with a quality binder will outperform gloss for both longevity and appearance.
Application technique for brick surfaces
A standard roller doesn't cover brick well. The mortar joints sit recessed below the brick face, and a smooth roller skips over them rather than forcing paint into the profile. Apex Painters Melbourne uses a thick-nap roller (20mm to 25mm nap) for commercial brick. The longer fibres compress into joints and cavities, ensuring even coverage across the full texture.
On the first primer coat, Apex Painters Melbourne often cross-rolls: applying in one direction, then rolling perpendicular before the coat sets, to push product into the surface from two angles. This eliminates the skip marks that straight-line rolling leaves on rough brick. A brush is used to stipple mortar joints on any section where the roller leaves voids.
Between coats, a light inspection under raking light identifies any pinholing or skipped mortar. These are spotted with a brush before the second coat goes on. Skipping this check means pinholes become air pockets under the finish coat that telegraph through the surface over time.
Clear coatings on raw brick: when to use them
Not every commercial client wants a coloured paint on their brick. Many office and hospitality fit-outs want to preserve the raw look while protecting the brick from dust, grease and scuff marks. A penetrating silane or siloxane sealer is the right product for this. It soaks into the brick face and repels water without forming a visible film, so the brick looks the same but resists staining and moisture ingress.
Clear coatings don't hide previous repairs, colour variation or staining. If the brick has visible patches or mortar-colour inconsistencies, a tinted masonry wash is sometimes more appropriate than a full opaque coat. It adds a layer of colour while still allowing the brick texture and variation to read through.
For a full commercial painting brief that covers surface-specific decisions like these, the process of writing a detailed commercial painting brief helps ensure the contractor knows exactly what product category to specify before quoting.
Maintenance after painting commercial brick
Painted brick in commercial spaces needs periodic inspection rather than frequent repainting. Apex Painters Melbourne recommends checking painted brick walls every 12 months for three specific signs: blistering near floor level (ground moisture ingress), chalking on the surface (UV degradation of the binder) and mortar joint cracking beneath the paint film.
Spot repairs on brick are harder to make invisible than on plaster, because the texture makes blending difficult. For commercial spaces where the wall is a feature, Apex Painters Melbourne recommends full-section repainting rather than spot touching up, as touch-up painting in occupied commercial spaces on textured surfaces rarely achieves an invisible result without careful full-wall blending.
A quality masonry paint system on properly prepared commercial brick typically holds well for 8 to 12 years before full repainting is needed. The preparation is what earns that lifespan. Skimping on primer coats or rushing past efflorescence treatment shortens that window to 3 to 4 years, which is a poor return on the disruption of having the work done in the first place.