When it comes to roofing, most people focus on the visible part—shingles. However, there is much more to your roof than meets the eye. A roof is made up of several important layers working together to protect your home from the elements. So, what is under roof shingles, and why does it matter? In this article, we'll dive into the various layers beneath your shingles and explain how they contribute to your roof's strength, longevity, and weather resistance.
1. The Role of Roof Shingles
Before we get into what is under roof shingles, it's essential to understand the role of shingles themselves. Shingles are the outermost layer of the roof that protects the home from rain, snow, wind, and UV radiation. They also add aesthetic value, giving your home a distinct look. But shingles alone cannot do all the work. Beneath the surface, there are multiple layers that support the shingles and ensure your roof functions effectively.
2. What Is Under Roof Shingles? An Overview of Key Layers
Now, let's explore what is under roof shingles and how these hidden components come together to form a complete roofing system. Each layer plays a crucial role in waterproofing, insulation, and protecting the structural integrity of your home.
a. Roof Decking (Sheathing)
The first and most essential layer under your roof shingles is the roof decking, also known as sheathing. This layer forms the base of the roof and is usually made from plywood or oriented strand board (OSB). Roof decking provides structural support and acts as a foundation to which the other roofing materials, including shingles, are attached.
Why It’s Important:
- Provides structural stability
- Acts as the base for other roofing layers
- Distributes weight evenly across the roof
Without a strong roof deck, the entire roofing system could fail, leading to serious structural problems.
b. Underlayment
Directly on top of the decking is the underlayment, which is a critical waterproofing layer. Typically made of felt (asphalt-saturated) or synthetic materials, the underlayment serves as an additional moisture barrier. It helps prevent water from seeping through the shingles and reaching the roof decking.
Why It’s Important:
- Adds an extra layer of waterproofing
- Provides protection if shingles are damaged
- Helps with insulation and energy efficiency
Choosing a high-quality underlayment is vital because it plays a crucial role in preventing leaks and damage caused by moisture.
c. Ice and Water Shield
In regions where cold weather is a concern, an ice and water shield is often installed beneath the underlayment, particularly in vulnerable areas like roof valleys and eaves. This layer is a self-adhering membrane that provides extra protection against ice dams and heavy rainfall, which can cause water to back up under the shingles.
Why It’s Important:
- Prevents leaks caused by ice dams
- Offers additional moisture protection in areas prone to water pooling
- Protects vulnerable areas such as valleys, eaves, and around chimneys
For homeowners in colder climates, the ice and water shield is a critical component of what is under roof shingles.
d. Drip Edge
A drip edge is a metal flashing installed along the edges of the roof to guide water away from the fascia and into the gutters. It helps prevent water from pooling on the roof’s edge and protects the underlying layers from moisture damage.
Why It’s Important:
- Directs water away from vulnerable areas of the roof
- Protects the fascia and underlying roof layers from water damage
- Improves overall roof durability
Without a properly installed drip edge, water can seep under the shingles and damage the roof deck, leading to costly repairs.
e. Roof Flashing
Roof flashing is typically made of metal (aluminum, steel, or copper) and is installed around areas where the roof meets vertical surfaces, such as chimneys, skylights, and vents. Flashing ensures that water does not leak into these junction points, where leaks are more likely to occur.
Why It’s Important:
- Seals roof penetrations and prevents water from entering
- Protects critical areas of the roof from leaks
- Adds to the overall weatherproofing of the roof
Flashings are often overlooked, but they play a critical role in what is under roof shingles and how your roof stays leak-free.
3. The Importance of Ventilation
Another important consideration when asking what is under roof shingles is proper roof ventilation. While ventilation isn't a physical layer under the shingles, it plays a key role in ensuring that moisture and heat don't build up in the attic, which can cause damage to the roofing materials.
a. Ridge Vents and Soffit Vents
Ridge vents are installed along the top ridge of the roof, while soffit vents are located under the eaves. These vents work together to promote airflow, which helps regulate the temperature and moisture levels in the attic.
Why It’s Important:
- Prevents heat and moisture buildup in the attic
- Extends the life of the roofing materials
- Helps improve energy efficiency by reducing cooling costs
Without proper ventilation, heat and moisture can cause mold, rot, and damage to the structural components of your roof.
4. Insulation: Supporting the Roofing System
Insulation is another key element of what is under roof shingles. It helps maintain a comfortable indoor temperature and prevents heat loss through the roof. Insulation is typically installed in the attic space, but it plays a vital role in the overall performance of the roof by working in tandem with the roofing materials.
a. Types of Insulation
- Fiberglass Batt Insulation: Commonly used in residential homes, this type of insulation is cost-effective and easy to install.
- Spray Foam Insulation: Offers a higher R-value (insulation rating) and provides better air sealing compared to traditional fiberglass.
Why It’s Important:
- Reduces energy costs by improving temperature regulation
- Protects the roof by preventing temperature extremes
- Minimizes the risk of ice dams in colder climates
Proper insulation works with ventilation to keep your roof in good condition and ensure energy efficiency.
5. The Importance of Regular Roof Inspections
Knowing what is under roof shingles is only part of the equation. Regular inspections and maintenance are crucial to ensuring the longevity of your roofing system. Over time, elements like the underlayment or flashing may degrade, leading to potential leaks or damage. By scheduling regular roof inspections, you can catch problems early and avoid costly repairs.
a. Professional Roof Inspections
A professional roofer will check for:
- Damaged or missing shingles
- Leaks or signs of water damage
- Problems with flashing, drip edges, or vents
- Moisture buildup or signs of mold in the attic
b. Self-Inspection Tips
If you're not ready for a professional inspection, you can conduct a basic check by:
- Looking for cracked, curled, or missing shingles
- Inspecting gutters for granule loss (from asphalt shingles)
- Checking the attic for signs of leaks or moisture
Regular maintenance helps keep the layers under your shingles functioning correctly and extends the life of your roof.
6. Why Understanding What Is Under Roof Shingles Matters
Knowing what is under roof shingles allows you to better understand how your roof functions and why it’s important to keep all layers in good condition. Each layer works together to protect your home from weather and other elements. Without a solid foundation, even the highest-quality shingles won’t last as long as they should.
For example, if the roof deck is damaged or the underlayment is compromised, water can infiltrate your home, causing mold, rot, and structural issues. Similarly, poor ventilation or insufficient insulation can lead to temperature extremes that damage your roof over time.
7. Conclusion
In conclusion, the answer to what is under roof shingles involves multiple layers that each play a critical role in protecting your home. From the roof decking and underlayment to flashing and ventilation, these components work together to ensure your roof remains durable and effective against the elements. By understanding these layers and conducting regular maintenance, you can extend the life of your roof and prevent costly repairs down the line.
Whether you’re planning a new roof installation or simply want to maintain your current one, knowing what is under roof shingles helps you make informed decisions about materials and roofing services.
FAQs
What is under roof shingles?
Under roof shingles are layers like the roof decking, underlayment, ice and water shield, drip edge, and flashing that work together to protect your home.Why is underlayment important?
Underlayment acts as a waterproof barrier that prevents water from seeping into the roof decking, protecting your home from leaks.How does roof flashing prevent leaks?
Flashing seals areas where the roof meets chimneys, vents, and other vertical surfaces, preventing water from entering these vulnerable spots.What role does ventilation play in the roofing system?
Ventilation helps regulate temperature and moisture levels in the attic, which extends the life of roofing materials and improves energy efficiency.Do I need an ice and water shield for my roof?
Ice and water shields are essential in colder climates where ice dams and heavy rainfall can lead to leaks and water damage.How often should I inspect my roof?
It’s recommended to have your roof professionally inspected at least once a year and after major storms to ensure all layers are intact.