A flawless exterior paint finish starts with proper preparation.
Whether you're giving your home a fresh new look or repainting weathered masonry, taking the time to prepare your exterior walls properly will help your paint last longer, provide better protection against Ireland's changing weather, and deliver a professional-quality finish.
At Ted Johnsons, we know that preparation is just as important as choosing the right paint. Follow our simple step-by-step guide to get your exterior surfaces ready before opening your first tin of masonry paint.
Why Is Exterior Wall Preparation So Important?
Exterior walls face some of the toughest conditions all year round. Rain, frost, UV rays, pollution, algae and fluctuating temperatures gradually wear down painted surfaces.
Painting over dirt, damaged render or unstable surfaces can result in:
- Peeling or flaking paint
- Poor adhesion
- Uneven colour and finish
- Reduced durability
- Costly repainting much sooner than expected
By preparing your walls correctly, you'll create a stable surface that allows your exterior paint to bond properly, helping it stay looking its best for years.
Step 1: Thoroughly Clean Your Exterior Walls
Before applying any primer or paint, your walls should be completely clean.
Remove:
- Dirt and dust
- Loose or flaking paint
- Algae and mould
- Pollution stains
- Salt deposits (particularly in coastal locations)
Pressure Washing Tips
Using a pressure washer is one of the quickest and most effective ways to prepare masonry surfaces.
For the best results:
- Work from the top of the wall downwards.
- Keep the nozzle moving to avoid damaging the render.
- Remove all loose paint and debris.
- Allow the surface to dry completely before continuing.
In Ireland, drying can typically take 24 to 48 hours, depending on weather conditions.
Step 2: Remove Algae and Mould
Many Irish homes develop green staining, algae or mould due to damp conditions and shaded areas.
Painting over organic growth allows it to continue spreading beneath the new coating, reducing the lifespan of your paintwork.
Best Practice
- Remove all visible growth during washing.
- Apply a suitable fungicidal treatment where required.
- Leave the wall to dry fully before moving on.
This step is particularly important for homes exposed to driving rain or high levels of moisture.
Step 3: Repair Any Damage
Once the wall is clean and dry, inspect the entire surface carefully.
Look for:
- Hairline cracks
- Loose render
- Damaged masonry
- Holes or chips
- Areas where paint has lifted
Small repairs now can prevent much larger problems later.
Repair Tips
- Remove all loose material.
- Fill cracks using an exterior-grade filler or repair mortar.
- Sand repairs smooth once cured.
- Brush away all dust before priming or painting.
A smooth, stable surface produces a far better final finish.
Step 4: Prime Bare or Repaired Surfaces
If you've repaired cracks, filled holes or have areas of bare masonry, applying a quality masonry primer will help create a uniform surface and improve the adhesion of your topcoat.
We recommend Fleetwood Masonry Primer Paint, which helps to:
- Seal repaired and porous areas
- Improve adhesion of masonry paint
- Promote even colour coverage
- Create a durable foundation for your exterior paint finish
Allow the primer to dry fully, following the manufacturer's instructions, before applying your chosen exterior masonry paint.
Top Tip: If your walls are particularly chalky or powdery, a stabilising solution may still be required before priming. If you're unsure which product is right for your project, our team at Ted Johnsons can help you choose the best preparation system.
Step 5: Choose the Right Weather
Even premium exterior paint performs poorly if the weather isn't suitable.
Ideal Painting Conditions
For the best results, choose a day with:
- Dry weather
- Mild temperatures
- No rain forecast
- Minimal wind
- No intense direct sunlight
Spring and summer generally provide the best opportunities for exterior painting in Ireland, but always check the forecast before you begin.
Essential Tools for Exterior Wall Preparation
Having the right equipment makes preparation easier and helps deliver a better finish.
Recommended tools include:
- Pressure washer
- Paint scraper
- Wire brush
- Exterior filler knives
- Sandpaper or sanding blocks
- Masonry brushes and rollers
- Dust sheets
- Masking tape
- Extension poles for hard-to-reach areas
Investing time in preparation will save time during painting and improve the overall appearance of your finished project.
Ready to Start Painting?
Before you begin painting, make sure your walls are:
✔ Clean
✔ Completely dry
✔ Free from algae and mould
✔ Properly repaired
✔ Stabilised where necessary
Once these steps are complete, you're ready to apply your chosen exterior masonry paint with confidence.
Visit Ted Johnsons for Everything You Need
Whether you're refreshing your home's exterior or tackling a full renovation, Ted Johnsons has everything you need for a long-lasting finish.
We stock leading brands including Fleetwood, Colourtrend, Dulux, Little Greene, Farrow & Ball, Tikkurila, and a full range of preparation products, fillers, stabilisers, brushes, rollers and accessories.
Our experienced team is always happy to help you choose the right products for your project.
Visit us in-store in Naas or shop online for quality paint and decorating supplies delivered across Ireland.
Frequently Asked Questions
How long should exterior walls dry after pressure washing?
In most cases, allow 24 to 48 hours, depending on temperature, humidity and recent rainfall.
Can I paint over algae?
No. Algae and mould should always be removed and treated before painting to prevent them returning beneath the new paint.
Do I need a masonry stabiliser?
If your walls are chalky, porous or weathered, using a masonry stabiliser will improve adhesion and help your paint last longer.
What's the best weather for exterior painting?
Choose a dry, mild day with no rain forecast, light winds and moderate temperatures for the best results.