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Posted by: Nathan Keiser

7 Layers of a Roof (Homeowner’s Guide)

Calender 03/18/2024
Clock 7 min READ

When it comes to understanding your home, the roof is one of the most critical components. But what exactly lies beneath those shingles? Let’s peel back the layers of a roof and explore the anatomy of a typical roof to gain a deeper appreciation for its complexity and functionality.

Inside this blog:

Keep reading to learn everything you need to know about the roof that hangs over your home’s head!

Layer 1: Roof Deck


The roof deck serves as the foundation for the rest of the roofing system. It’s typically made of plywood or oriented strand board (OSB) and provides a sturdy base for the other layers to sit on.

Material for the Roof Deck

The roof deck is typically constructed from Plywood or OSB, sturdy materials known for their strength and durability, capable of withstanding the weight of the roofing materials above.

Purpose of the Roof Deck

Serving as the backbone of the roofing structure, the roof deck provides essential structural support, ensuring that the weight of the roofing materials and any external elements, such as snow or wind, is evenly distributed across the entire roof surface.

Importance of the Roof Deck

Without a solid and stable roof deck, the integrity of the entire roofing system could be compromised. It plays a crucial role in maintaining the structural integrity of the roof, preventing sagging or collapsing and ensuring that the roof can withstand the rigors of various weather conditions over time.

Layer 2: Underlayment


The underlayment acts as a secondary barrier against water infiltration and helps protect the roof deck from moisture damage. It’s installed directly on top of the roof deck before the shingles are applied.

Material for Underlayment

Underlayment is typically made from asphalt-saturated felt or synthetic materials engineered to repel moisture effectively and provide an additional barrier against water infiltration.

Purpose of Underlayment

The primary function of underlayment is to provide waterproofing and added protection to the roof deck and structure. It acts as a secondary line of defense against water penetration, safeguarding the interior of the home from potential leaks and water damage.

Importance of Underlayment

Underlayment plays a critical role in maintaining the integrity of the roofing system by helping to prevent leaks and prolonging the life of the roof.

Layer 3: Shingles


Shingles are the most visible part of the roof and serve as the primary layer of protection against the elements. They come in various materials, including asphalt shingles, wood, metal, and composite, each offering its own unique benefits and aesthetic appeal.

Materials for Shingles

Shingles are available in various materials, including asphalt, wood, metal, or composite, allowing homeowners to choose the option that best suits their budget, style, and climate requirements.

Purpose of Shingles

Shingles serve as the outermost layer of the roof, providing essential protection against rain, wind, sunlight, and other environmental elements. Their durable construction helps shield the underlying roof structure from moisture infiltration and damage.

Importance of Shingles

Shingles play a crucial role in enhancing the appearance and weatherproofing of the roof, contributing to both the aesthetic appeal and functionality of the home.

Layer 4: Flashing

Flashing is installed around roof penetrations such as chimneys, vents, and skylights to prevent water from seeping into the seams and causing leaks. It’s typically made of metal and provides a watertight seal at vulnerable areas of the roof.

Materials for Flashing

Flashing is typically crafted from metal, such as aluminum or galvanized steel, known for its durability and resistance to corrosion, ensuring long-lasting protection for your roof.

Purpose of Flashing

Flashing plays a crucial role in redirecting water away from vulnerable areas of the roof, such as valleys, chimneys, vents, and skylights, preventing moisture infiltration and potential water damage.

Importance of Flashing

Properly installed flashing serves as a barrier against leaks and water damage, safeguarding the roof’s integrity and structural components around roof penetrations, thereby extending the lifespan of the entire roofing system.

Layer 5: Ridge Vent


The ridge vent is installed along the peak of the roof to allow for proper attic ventilation. It works in conjunction with soffit vents to create airflow and remove excess heat and moisture from the attic space.

Materials for the Ridge Vent

Ridge vents are commonly constructed from durable materials like plastic or metal, ensuring longevity and resistance to weathering over time.

Purpose of the Ridge Vent

Ridge vents serve as an essential component of attic ventilation systems, allowing hot air and moisture to escape from the attic space, thereby regulating temperature and humidity levels inside the home.

Importance of the Ridge Vent

Proper attic ventilation provided by ridge vents helps prevent moisture buildup, condensation, and mold growth in the attic. This promotes a healthier indoor environment and prolongs the lifespan of the roof by reducing the risk of structural damage caused by excess humidity.

Layer 6: Ice and Water Shield

Ice and water shield is a self-adhesive membrane installed in areas prone to ice dams and water intrusion, such as eaves and valleys. It provides an additional layer of protection against water penetration and helps prevent damage caused by ice buildup.

Materials for Ice and Water Shield

Ice and water shields are typically constructed from durable materials such as rubberized asphalt or synthetic polymers, ensuring flexibility and resistance to cracking or tearing in extreme weather conditions.

Purpose for Ice and Water Shield

Ice and water shields act as a waterproof barrier, specifically designed to provide added protection in vulnerable areas of the roof, such as valleys, eaves, and around protrusions like chimneys or skylights.

Importance of Ice and Water Shield

The presence of ice and water shields is crucial for preventing water infiltration during periods of heavy rain, snowmelt, or ice dams, which can lead to costly water damage and structural issues if left unchecked.

Layer 7: Drip Edge


The drip edge is a metal flashing installed along the edges of the roof to direct water away from the fascia and into the gutters. It helps prevent water from pooling along the roofline and causing rot or water damage to the underlying materials.

Materials for the Drip Edge

The drip edge is typically constructed from corrosion-resistant materials such as aluminum or galvanized steel, ensuring longevity and durability in various weather conditions.

Purpose of the Drip Edge

Acting as a barrier between the edge of the roof and the fascia board, the drip edge directs water away from the roof edge, preventing it from seeping into the underlying structure.

Importance of the Drip Edge

Installing a drip edge is essential for protecting the fascia board and preventing water damage to the roof structure, as it helps to channel water away from the vulnerable areas of the roof, reducing the risk of rot, mold, and decay.

An Empowered Homeowner Understands Their Roof

Understanding the various layers of your roof is essential for proper maintenance and upkeep. By familiarizing yourself with these components, you can better identify any issues and ensure that your roof remains in good condition for years to come.

Get in touch with our roofing experts at Kraft Roofing and experience top quality workmanship and unbeatable customer service. We can’t wait to hear your questions about the roof that hangs over your home’s head. Let’s get the ball rolling on your next roofing project today!

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