When it comes to building a long-lasting roof in a climate like Kerala’s—where high humidity, intense rainfall, and strong sun are common—shingle underlayments are just as crucial as the shingles themselves. Acting as the unseen layer of protection between your roof deck and shingles, underlayments play a key role in both waterproofing and breathability.
But here’s the twist: these two goals often conflict with each other. So, how do modern underlayments manage to balance breathability and water resistance, and why does it matter?
Let’s explore the science behind it—and how choosing the right solution from Scaffs India can extend your roof’s lifespan and performance.
What is a Shingle Underlayment?
A roofing underlayment is a protective sheet installed beneath your shingles. Its primary purpose is to act as a secondary moisture barrier, protecting the roof structure in case shingles are damaged or displaced.
There are three main types:
Asphalt-saturated felt (traditional)
Synthetic underlayments (modern)
Self-adhered waterproof membranes
Breathability vs. Waterproofing: The Roofing Paradox
🌧️ Waterproofing: Keeping Moisture Out
Waterproofing is non-negotiable. The underlayment must prevent:
Wind-driven rain from penetrating the roof deck
Leaks caused by ice dams or heavy rain pooling
Water damage due to shingle granule loss or failure
Advanced options like self-adhered membranes and synthetic underlayments offer exceptional waterproofing while resisting rot and fungal growth—perfect for humid Kerala conditions.
💨 Breathability: Letting Moisture Escape
But a roof also needs to “breathe.” Why?
Trapped moisture inside the roofing system (from indoor humidity or condensation) must escape to prevent:
Rotting timber
Mould growth
Premature deterioration
That’s why breathable synthetic underlayments are now favoured—they allow vapour to escape without letting water in.
✅ The best underlayments are both vapour-permeable and water-resistant—a perfect balance engineered through advanced material science.
Real-World Performance in Kerala’s Climate
In regions like Kerala with high rainfall and humidity, roof underlayments need to work double-time. Here’s what happens if you choose the wrong type:
| Underlayment Type | Breathability | Waterproofing | Suitability in Kerala |
|---|---|---|---|
| Asphalt Felt | Low | Moderate | ❌ Outdated, absorbs water |
| Synthetic Breathable | High | High | ✅ Best for long-term use |
| Self-Adhered Membrane | Low-Moderate | Excellent | ✅ Use in valleys, edges |
For long-term durability and thermal performance, Scaffs India’s roofing systems incorporate high-quality, climate-specific underlayment technologies.
Why This Matters for Energy Performance (EPC)
A well-ventilated, breathable roofing system reduces attic humidity, which:
Improves HVAC efficiency
Minimises mould and insulation damage
Supports a better Energy Performance Certificate (EPC) score
In contrast, a non-breathable roof traps moisture, increasing your energy consumption and decreasing your home’s thermal performance.
Upgrade your EPC potential with breathable roof systems like:
Borja Tech Tiles with advanced water resistance
Best Practices When Choosing Underlayment
✔️ Use synthetic breathable membranes for large surface areas
✔️ Install self-adhered waterproof barriers at vulnerable spots (valleys, eaves, skylights)
✔️ Combine with Scaffs India accessories like ridge vents and moisture guards
✔️ Pair with high-performance shingles like Designer Roofing Shingles
Why Scaffs India Roofing Systems Are Built to Breathe
At Scaffs India, we don’t just sell roofing shingles—we deliver complete roofing ecosystems designed for Kerala’s weather extremes.
Whether you’re building a modern A-Frame Cottage, Mudroom Cottage, or upgrading a traditional villa, our team ensures the right underlayment supports your aesthetic goals, energy savings, and roof longevity.
Conclusion
The science of shingle underlayments lies in balancing water protection with breathability—especially in high-humidity climates. With the right materials and expert installation, your roof won’t just survive Kerala’s weather—it will thrive.
🛠️ Looking for a leak-proof yet breathable roofing solution?
👉 Explore Our Roofing Services
📞 Contact Scaffs India for a site assessment
🔗 View Our Completed Roofing Projects