Brick, render, concrete and masonry surfaces are designed to withstand years of exposure to Australia's climate, but even the most durable materials change over time. Sun, rain, moisture, dust and general weathering can gradually leave surfaces chalky, porous or unstable. When these issues are overlooked, new paint may struggle to adhere properly, increasing the risk of peeling, flaking, uneven coverage and reduced durability.
Since 1935, Haymes Paint has helped Australians protect and refresh their homes with paint systems developed for local conditions. As Australia's largest Australian Made and Owned paint manufacturer, we understand that long-lasting exterior results depend as much on preparation as they do on the paint itself.
Why Exterior Masonry Paint Fails Before the Topcoat Goes On
Many common exterior paint problems can be traced back to surface preparation issues.
Masonry surfaces are constantly exposed to changing conditions. Over time, this can lead to chalking, increased porosity, cracking, contamination, mould growth and deterioration of existing paint films. If these issues are not addressed before repainting, they can affect the performance of subsequent coats.
Common signs of a surface that requires additional preparation include:
- Chalking or powdery residue
- Peeling or flaking paint
- Uneven absorption
- Surface erosion
- Mould growth
- Efflorescence
- Cracks or damaged areas
We recommend ensuring surfaces are clean, dry and free from contaminants before painting. Where mould is present, it should be treated and removed before coating. Proper preparation creates the foundation for the entire paint system.
What Chalking Looks Like on Masonry
Chalking occurs when the surface begins to break down, leaving a fine powdery residue. It is commonly found on older painted masonry surfaces that have been exposed to the weather for extended periods.
A simple way to check for chalking is to rub your hand across the wall. If you notice a powdery residue on your fingers, the surface is likely chalking.
Other signs include:
- Faded appearance
- Dusty-looking paint
- Uneven colour
- Residue transferring onto clothing or hands
- A dry, powdery texture
Identifying chalking early is important because it helps determine whether additional cleaning, sealing or priming may be required before repainting.
How Weathered Masonry Differs from Chalking
Weathered masonry can appear in several ways depending on the substrate and its exposure history.
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Surface
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Common Signs
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Potential Preparation Requirements
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Brick
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Fading, porosity, uneven absorption
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Cleaning and sealing
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Render
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Hairline cracks, chalking, weathering
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Repairs, sealing and priming
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Concrete
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Dustiness, porosity, surface wear
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Cleaning and sealing
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Masonry surfaces
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Existing paint failure, uneven texture
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Adhesion testing and preparation
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Weathered surfaces often absorb paint differently from newer or well-maintained substrates. Understanding the condition of the surface helps determine the most appropriate preparation method.
Do You Need a Primer?
The answer depends on the condition of the surface. A sound, clean and well-adhered previously painted surface may not require the same level of preparation as a chalky, porous or repaired wall. However, as surfaces become more weathered, the role of primer becomes increasingly important.
Primer may be recommended where:
- Masonry is chalky
- The surface is porous
- Repairs have been completed
- Existing coatings show signs of uneven absorption
- Additional adhesion support is required
Rather than viewing primer as an optional extra, it is helpful to think of it as part of the overall paint system. Its role is to help create a more uniform and stable surface before the topcoat is applied.
Check Whether Existing Paint Is Still Sound
Before deciding on a primer, assess the condition of any existing paint. We recommend conducting an adhesion test on previously painted surfaces. This involves cutting a light "X" into the coating, applying adhesive tape over the cut and removing it sharply. If the existing coating lifts with the tape, it should be removed before repainting.
This simple test helps determine whether the existing paint can remain in place or whether additional preparation is required. We also recommend compatibility testing when repainting previously coated surfaces.
Clean Masonry Before You Prime
Cleaning is often the most overlooked step in exterior painting. Dust, dirt, mould, salt deposits and other contaminants can interfere with adhesion and affect the finish of the completed project.
It’s best to pressure wash cement render, concrete, masonry and AAC surfaces before painting and allow them to dry thoroughly afterwards. Concrete should also be free from bond breakers, formwork release agents and efflorescence before coating.
Before priming, ensure the surface is:
- Clean
- Dry
- Free from loose material
- Free from mould
- Free from grease and contaminants
Taking the time to clean properly can help create a more suitable surface for subsequent coats.
Repair Cracks and Damaged Areas
Before applying primer, repair cracks, holes and damaged sections of masonry. Remove loose material, allow repairs to cure fully and sand smooth where required. This step is particularly important because repaired areas can absorb paint differently from the surrounding surface. Appropriate sealing and priming helps create a more consistent substrate before topcoating.
If masonry is affected by ongoing moisture issues or significant structural cracking, these problems should be addressed before repainting.
Why Primer Selection Matters
Different masonry surfaces present different preparation challenges. A chalky surface behaves differently from a previously painted wall, and a repaired render patch absorbs paint differently from aged brickwork.Â
Choosing a primer that matches the condition of the substrate helps create a more uniform foundation for the paint system.
Choose Ultraseal® for Chalky or Porous Masonry
Haymes Paint Prepcoat Acrylic Sealer Undercoat Ultraseal® is recommended for:
- Chalky masonry
- Porous masonry
- Repaired areas
- Weathered substrates requiring sealing
Ultraseal® helps seal porous surfaces and create a more consistent foundation before applying exterior topcoats.Â
Choose Ultracover® for Sound Previously Painted Surfaces
Haymes Paint Prepcoat Primer Sealer Undercoat Ultracover® is suited to situations where:
- Existing paint remains sound
- Additional surface uniformity is required
- Adhesion support is needed
- Weathered painted surfaces are being refreshed
Note that new concrete should be allowed to cure for 28 days before painting.
Apply a Suitable Exterior Topcoat
Once preparation is complete, select an exterior finish designed for masonry surfaces. The Solashield® range is suitable for brick, render, concrete and masonry surfaces when correctly prepared.
Solashield® incorporates anti-ageing Surface Lock Technology, creating a barrier designed to repel mould, dust and dirt while helping defend against UV exposure. The range includes:
Explore the Solashield® range, browse the wider exterior paint range or discover colour collections to help plan your project.
Common Preparation Mistakes That Lead to Paint Failure
Preparation shortcuts often create avoidable problems later. Common mistakes include:
- Painting over chalking
- Skipping adhesion testing
- Inadequate cleaning
- Painting damp masonry
- Ignoring efflorescence
- Using an unsuitable primer
- Painting in unsuitable weather conditions
We advise against painting in direct sunlight and recommend avoiding application when rain or dew is expected within 24 hours.
Frequently Asked Questions
Can I paint directly over chalky masonry? It is generally better to clean and prepare the surface first. Where masonry is chalky or porous, a suitable sealer undercoat such as Ultraseal® may be recommended.
What primer should I use on old render? The answer depends on the condition of the render. Chalky or porous render may benefit from Ultraseal®, while sound previously painted render may be better suited to Ultracover®.
Do I need to pressure wash masonry before painting? We suggest pressure washing masonry, render and concrete surfaces as part of preparation before allowing them to dry thoroughly.
Can I paint over existing masonry paint? Yes, provided the existing coating remains sound and passes adhesion testing.
How long should new concrete cure before painting? We recommend allowing new concrete to cure for 28 days before painting.
Build the Finish from the Surface Up
The most important lesson from any masonry painting project is that preparation and paint performance are closely connected.
Visit your nearest Haymes Paint stockist for personalised project advice, explore the Solashield® exterior range, and find the right primer for your next exterior project.
The colour and finish may be what people notice first, but the durability of the result is often decided long before the topcoat goes on.
