What Is Mineral Paint? A Guide for Architects, Designers and Homeowners
- Jul 8
- 8 min read
What is mineral paint?
Mineral paint is a paint system made from natural mineral ingredients, inorganic pigments and a silicate binder. Unlike conventional acrylic paint, which forms a synthetic (plastic) film over a surface, mineral paint works by bonding with mineral substrates such as render, concrete, stone, brick and masonry.
It is not simply a decorative layer sitting on top of a wall. It becomes part of the surface itself.
For architects, designers, builders and homeowners, that difference matters. The coating you choose can affect how a building breathes, how it manages moisture, how long colour remains stable and how often surfaces need to be repainted.
At KEIM, mineral paint is often described as liquid stone, not liquid plastic. It is a useful way to understand the material. Rather than wrapping a building in a plastic film, mineral paint supports the natural behaviour of mineral surfaces.
How does mineral silicate paint work?
The key to mineral paint is the binder.
KEIM mineral paints use a silicate binder, often referred to as waterglass. When applied to a mineral substrate, this binder reacts with the surface through a process called silicification.
Silicification creates a chemical bond between the paint and the substrate. Instead of relying only on surface adhesion, the coating becomes mineralogically connected to the wall.
This is why mineral silicate paints are known for their durability. They do not peel in the same way many film-forming paints can, because they are not simply sitting on top of the surface. They are bound into it.
On suitable substrates, this creates a finish that is:
Highly breathable
Exceptionally durable
UV stable
Colour-fast
Resistant to blistering and flaking
Naturally mineral in appearance
Suited to masonry, render, concrete and heritage surfaces
This makes mineral paint particularly valuable on buildings where longevity, breathability and material integrity are priorities.
Mineral paint versus acrylic paint
Most conventional architectural paints are acrylic or polymer-based. They are popular because they are familiar, widely available and easy to apply. But they behave very differently to mineral paint.
Acrylic paint generally forms a film over the surface. On some substrates, that may be acceptable. But on mineral surfaces such as masonry, concrete and render, a sealed film can restrict moisture movement.
Buildings are exposed to changing conditions every day. Rain, humidity, heat, salt air, condensation and internal moisture all affect how walls perform. When moisture becomes trapped behind a less breathable coating, it can contribute to bubbling, peeling, flaking, mould risk and premature coating failure.
Mineral paint takes a different approach. Rather than sealing the surface, it allows water vapour to pass through. This is often described as breathability or vapour permeability. In simple terms, the wall can release moisture naturally, instead of holding it behind a coating.
For older buildings, heritage masonry, concrete façades and high-performance architecture, that breathability can be a significant advantage.
Why breathability matters
Breathability is one of the most important reasons architects and specifiers choose mineral paint.
Mineral surfaces are naturally porous. Brick, stone, render and concrete absorb and release moisture as environmental conditions change. When these surfaces are coated with a product that blocks vapour movement, the coating can work against the building.
A breathable coating helps the substrate dry out. This can reduce the risk of moisture-related problems, particularly in:
Heritage buildings
Older masonry
Rendered façades
Coastal environments
Humid climates
Concrete structures
Interiors where indoor air quality matters
Buildings exposed to regular weather changes
Breathability is not only about protecting the paint finish. It is about supporting the long-term health of the wall beneath it.
Why mineral pigments are different
Colour in mineral paint behaves differently too. KEIM mineral paints use inorganic mineral pigments, selected for their lightfastness and stability. Because these pigments are mineral-based, they are highly resistant to UV degradation.
This is why mineral colours can remain vibrant for decades, even on exposed façades. They do not rely on the same organic colourants that can fade or break down over time.
Mineral paint also has a distinctive appearance. It interacts with light in a softer, more natural way than many synthetic coatings. The finish can feel matte, deep and alive, with a mineral character that suits both contemporary and heritage architecture.
For designers, this matters. Colour is not only about the shade selected from a chart. It is also about surface, depth, light and materiality.
Is mineral paint plastic-free?
One of the biggest conversations in modern paint specification is the difference between low VOC and plastic-free.
Low VOC paints can still contain plastic binders. They may have reduced odour or lower emissions during application, while still forming a synthetic film over the surface. Mineral paint is different.
KEIM’s mineral paint philosophy is based on mineral raw materials, fillers and pigments, without added biocides, solvents, plasticisers or VOCs. The result is a paint system designed around mineral performance rather than plastic film formation.
For interiors, this supports healthier indoor environments. For exteriors, it supports long-term façade performance, breathability and reduced maintenance.
For sustainable architecture, this distinction is important. Paint should not be judged only by what evaporates during application. It should also be judged by what remains on the wall for decades.
Why mineral paint lasts longer
Durability is one of the strongest arguments for mineral paint. Because mineral silicate paint chemically bonds to suitable substrates, it is less prone to the failure patterns associated with many film-forming coatings. It does not rely on a flexible plastic layer that can become brittle, degrade under UV exposure or lose adhesion over time.
A high-quality mineral paint system can reduce repainting cycles, which has both financial and environmental benefits. Fewer repaints means less labour, fewer materials, less waste and less disruption to building occupants.
For commercial buildings, hospitals, civic architecture, schools, heritage sites and residential projects, this long-term view matters.
Paint is often treated as a finishing item. But in reality, it is a maintenance decision.
Choosing a longer-lasting coating can support the performance of the entire building.
Where is mineral paint used?
Mineral paint is used across a wide range of project types, including:
Heritage restorations
Public buildings
Hospitals and healthcare environments
Museums and galleries
Schools and universities
Residential homes
Apartments and multi-residential developments
Commercial façades
Concrete buildings
Murals and public artworks
Coastal and exposed environments
Its strength is versatility. Mineral paint can be used where appearance matters, but it is especially valuable where performance matters too.
Mineral paint in Australian architecture
Mineral paint has been used on some of Australia’s most significant architectural projects, from heritage icons to contemporary public buildings.
Sydney Opera House
The Sydney Opera House is one of Australia’s most recognisable architectural landmarks. On a building of this significance, material choice is never only about appearance. It is about conservation, longevity and respect for the original architecture.
KEIM Concretal-Lasur was selected as a mineral coating solution for exposed concrete surfaces, helping rejuvenate and protect the concrete while maintaining the character of the building.
This is a strong example of what mineral paint does best. It protects without masking. It supports the surface without turning it into something artificial.
Shell House, Sydney
Shell House is one of Sydney’s great adaptive reuse stories. Originally constructed in the late 1930s as the headquarters for Shell Oil Company, the building has been carefully restored and reimagined as part of the Brookfield Place Sydney precinct.
For heritage projects like this, coatings need to work with the existing building fabric. Mineral paint is well suited to this type of work because it offers durability, breathability and a refined mineral finish, without the heavy surface film associated with many conventional coatings.
Porter House Hotel
Porter House brings together heritage architecture and contemporary hotel design in the heart of Sydney. Across the project, concrete is a defining material.
KEIM Concretal-Lasur was used on the concrete façade elements, selected for its durability, vapour permeability and ability to preserve the natural mineral appearance of concrete.
This is a key advantage of mineral finishes on architectural concrete. They can unify, protect and refine the surface while still allowing concrete to read as concrete.
Joan Kirner Women’s and Children’s Hospital
At the Joan Kirner Women’s and Children’s Hospital in Sunshine, Melbourne, colour and materiality play an important role in the experience of the building.
The hospital’s colourful concrete façade supports wayfinding, identity and a more uplifting environment for patients, families and staff. KEIM Concretal-Lasur was used in custom colours, demonstrating how mineral paint can support expressive design while maintaining the performance benefits of a breathable, mineral coating system.
For healthcare environments, this combination is powerful. The finish is not just decorative. It contributes to the overall atmosphere, longevity and material quality of the building.
When should you choose mineral paint?
Mineral paint is a strong choice when you want a coating that does more than cover a surface.
It is especially worth considering when:
You are working with concrete, render, brick, stone or masonry
The building needs to breathe
You want to avoid plastic film-forming coatings
Colour stability is important
The project has sustainability or healthy material goals
The building is heritage, civic or architecturally significant
You want to reduce repainting cycles
You are specifying for long-term value, not just upfront cost
For homeowners, mineral paint is ideal for those who want healthier interiors, durable exteriors and a more natural finish.
For architects and designers, it offers a material-led approach to colour and surface.
For builders and asset owners, it offers long-term performance and reduced maintenance.
What surfaces can mineral paint be used on?
Mineral paint is best suited to mineral substrates, including:
Rendered walls
Concrete
Brick
Stone
Lime plaster
Cementitious surfaces
Mineral-based façade systems
As with any coating system, correct specification and surface preparation are essential. The right product depends on the substrate, exposure, existing coating, project type and desired finish.
Is mineral paint only for heritage buildings?
No. Mineral paint is highly valued in heritage restoration, but it is equally relevant to modern architecture.
In fact, many contemporary projects use mineral paint because it aligns with current priorities in design and construction:
Lower maintenance
Material honesty
Breathable building systems
Reduced synthetic content
Healthier interiors
Longer lifecycle performance
Natural matte finishes
High colour stability
Mineral paint is not old-fashioned. It is a proven material technology that feels more relevant than ever.
A better way to think about paint
The biggest shift is this: Paint is not just a colour.Paint is a material.
When you choose a coating, you are choosing how a surface will behave. You are choosing how it will age, breathe, reflect light, manage moisture and contribute to the building over time.
Acrylic paint has become the default in many parts of the industry. But default does not always mean best.
For mineral surfaces, mineral paint offers a more compatible approach. It works with the substrate, rather than sealing it off. It allows walls to breathe. It uses mineral pigments for lasting colour. It supports healthier interiors and more durable exteriors.
For architects, designers, builders and homeowners who care about performance, sustainability and long-term beauty, mineral paint is one of the smartest coating choices available.
Why choose KEIM mineral paints?
KEIM has been making mineral silicate paints since 1878. That history matters, because mineral paint is not a trend or a new sustainability claim. It is a proven material system with more than a century of real-world performance.
Today, KEIM mineral paints are used across residential, commercial, civic, healthcare, cultural and heritage projects around the world.
They are chosen because they offer:
Mineral-based composition
Exceptional breathability
Long-lasting colour
UV stability
No added VOCs, solvents, plasticisers or biocides
Durable performance on demanding substrates
A natural matte mineral finish
Long-term value over repeated repainting cycles
For any project where the finish needs to be beautiful, breathable and built to last, mineral paint offers a fundamentally different solution.
Want to feel the mineral difference? Order a Keim Swatch Book today!
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