Best Waterproof Masonry Paints for Rain‑Exposed Walls

It’s often the case that to keep your home dry and free from damp, it’s not enough to focus only on internal issues like condensation or poor ventilation. Your external walls also play a crucial role—and they’re frequently overlooked.

One effective way to reduce dampness caused by rain is to properly prepare and protect exterior walls using specialist coatings and waterproof masonry paints.

These protective solutions not only help keep your home dry and your walls moisture-free, but they can also save you money in the long run by reducing heat loss and avoiding costly repairs.

Two Best Waterproof Masonry Paints Options to Protect Exterior Walls

There are two primary ways to treat exterior walls that are exposed to rain or prone to damp:

Option 1: Apply Stormdry with a Breathable Masonry Paint

💧 What is Stormdry?

Stormdry Masonry Protection Cream is a clear, breathable waterproofer made with silicone. It penetrates deep into porous surfaces like brick, render, stone, or concrete and creates an invisible barrier that repels rainwater—while still allowing moisture from inside the wall to escape.

Think of it like a raincoat for your wall: water beads off, but the wall can still breathe.

⚠️ Important Warning: Don’t Use Standard Masonry Paint Over Stormdry

You cannot use standard masonry paint (like regular Dulux, Leyland, or Sandtex) over Stormdry.

Why?

• Stormdry creates a water-repellent surface.

• Standard paints (especially acrylic or vinyl-based ones) rely on absorption to adhere.

• So if you paint over Stormdry with standard masonry paint, it may:

  • Struggle to stick

  • Peel or flake

  • Fail to last as expected

🧱 Surfaces Stormdry Works On

🧪 Prep is Crucial: The wall must be bare and absorbent. Stormdry won’t work on previously painted or sealed walls.

🛠️ Can You Paint After Stormdry?

Yes, but only with the right paint:

• Wait at least 14 days for Stormdry to cure.

• Choose a highly breathable paint (like Emperor or mineral paints such as Keim or Earthborn).

• Always do a patch test for adhesion.

Alternatively, skip Stormdry and use a paint that does both jobs—like Emperor.

🧠 Quick Summary: Stormdry Combo

💰 Does Using Stormdry Mean You’ll Need Expensive Paint?

Not necessarily—but to preserve breathability, you can’t go cheap.

• Standard paints often block breathability and won’t adhere well to Stormdry-treated walls.

• That’s why breathable paints tend to be higher-end, like Keim, Earthborn, or Emperor.

🔄 Your Options Compared

✅ Tip: Stormdry is like a breathable raincoat. Don’t wear a plastic poncho (i.e. cheap paint) over it—it’ll trap moisture inside and cause more harm than good.

Option 2: Use a Waterproof, Breathable Paint on Its Own

Instead of using Stormdry plus a breathable paint, you can simply use a premium breathable waterproof paint. These paints offer both water resistance and breathability in one step—perfect for ease and performance.

🥇 1. Emperor Masonry Paint

• Silicone-based and super hydrophobic – rain beads off easily

• Highly breathable – allows internal moisture to escape

• No Stormdry needed

✅ Pros:

• Waterproof and breathable

• Self-cleaning and dirt-resistant

• Long-lasting (great for exposed walls)

👎 Cons:

• More expensive than standard paints

💷 Buy at:

• Painters World – £69 for 5L

• Emperor’s official site

🥈 2. Keim Soldalit Silicate Paint

• Mineral-based paint – naturally breathable and water-repellent

• Works beautifully on historic or lime-rendered walls

✅ Pros:

• UV-stable, colour-fast

• Mildew and algae resistant

👎 Cons:

• Not as water-repellent as silicone paints unless used with Stormdry

💷 Buy at:

• Keim Paint Shop (~£109 for 5kg)

• Promain or Brewers

🥉 3. Earthborn Ecopro Silicate Paint

• Breathable and eco-friendly silicate paint

• Lasts up to 15 years

• VOC-free and ideal for older buildings

✅ Pros:

• Durable, matte finish

• Helps prevent algae growth

👎 Cons:

• Needs a mineral primer and possibly Stormdry in wet areas

💷 Buy at:

• Paint-Direct

• Wood Finishes Direct

✅ Do You Still Need Stormdry with These Paints?

Paint Type	Stormdry Needed?
Emperor Paint	❌ No – waterproof & breathable alone
Keim Soldalit	✅ Yes – especially for exposed walls
Earthborn Ecopro	✅ Yes – recommended for damp-prone walls

🛠️ Final Thoughts: Which Should You Choose?

✔️ Choose Emperor

If you want a simple, all-in-one solution that’s waterproof, breathable, and durable—without needing Stormdry.

✔️ Choose Keim or Earthborn with Stormdry

If you have a heritage property, lime-rendered walls, or prefer eco-friendly mineral paints. Stormdry adds vital rain resistance.

Always follow proper surface prep:
Bare walls → Prime (if needed) → Two coats paint (diluted first coat for minerals)

Allow:

• Stormdry: 14 days to cure

• Paints: 6–12 hours per coat

🧠 Summary: Which Combo is Right for You?

🛍️ Quick Product Links:

• Stormdry Water Seal – Safeguard Europe

• Emperor Masonry Paint

• Keim Soldalit – Keim Paint Shop

• Earthborn Ecopro – Paint Direct