Choosing the Right Plaster for Your Home – Avoiding Damp & Breathability Issues

Did you know that using the wrong plaster could lead to trapped moisture, peeling walls, and even mould? Many homeowners unknowingly cause damp problems just by choosing the wrong finish.

So, how do you make sure your walls can "breathe" properly? Let’s break it down in simple terms.

What Is Plaster Breathability & Why Does It Matter?

Breathability refers to how well a material allows moisture to pass through. This is crucial in older homes because stone and brick naturally absorb and release moisture.

🔹 The Problem: Modern waterproof coatings trap moisture inside, leading to damp, paint failure, and long-term wall damage.

🔹 The Solution: Choosing the right breathable plaster prevents these issues and keeps your home healthy.

Which Plaster Should You Use? (Simple Comparison Table)

Plaster TypeBreathabilityBest ForAvoid If…Lime Plaster✅ Very breathableOld stone buildings, damp-prone wallsYou need a rock-hard, waterproof surfaceClay Plaster✅ Highly breathableEco-homes, natural materialsYou need a weatherproof finishGypsum Plaster⚠️ Somewhat breathableModern homes, indoor wallsYou have damp problems or want an exterior plasterCement Plaster❌ Not breathableNew builds, garagesOld homes—it can trap moisture & cause dampK Rend / Synthetic Plaster❌ Waterproof but traps moistureModern houses needing a tough exteriorOld stone homes—it blocks breathability

🛑 Key Takeaway: If your home was built before the 1920s, it likely needs a breathable plaster like lime or clay—NOT cement or synthetic render!

Real Example: How the Wrong Plaster Caused a Damp Nightmare

💬 "A customer contacted me about damp and mold spreading across their walls. Their home, built in the 1800s, had a basement living room where a previous builder had applied cement render. With no way for moisture to escape, it built up behind the render, causing it to crack and come away in large sections. We stripped it back to the original masonry and replaced it with a breathable lime render. Within weeks, the walls began to dry out naturally, allowing the home to regulate moisture as it was meant to”

How to Avoid Damp & Plastering Mistakes

✅ Check your home’s age – Older buildings = breathable plaster needed.
✅ Think about moisture – If walls feel damp, avoid waterproof finishes.
✅ Ask an expert – Don’t let a builder convince you K Rend is "better" for old homes—it’s not!

Final Thoughts – What’s the Right Plaster for You?

💡 For old houses: Use lime or clay to prevent moisture buildup.
💡 For modern houses: You can use gypsum inside and K Rend outside.
💡 Not sure? Always choose breathability—it’s better to be safe than sorry!

🚀 Need expert advice on plastering your home? Get in touch for a free consultation, and I’ll help you find the right solution!