Roofing Underlayment: Types, Installation, Maintenance, and Choosing the Right Option

by Keira April 25, 2024

written by Keira April 25, 2024

Roofing Underlayment: A Comprehensive Guide

Understanding Roofing Underlayment

Roofing underlayment is a crucial component of any roofing system, providing an additional layer of protection between the roof deck and the shingles. It serves as a waterproof barrier, preventing moisture from seeping into the home and damaging the roof structure. Roofing underlayment also provides insulation, helping to regulate the temperature inside the home.

Types of Roofing Underlayment

There are three main types of roofing underlayment: asphalt-saturated felt, rubberized asphalt, and synthetic.

Asphalt-Saturated Felt

Best for: Inexpensive roof repairs, slate shingles, and tile shingles
Key characteristics: Water-resistant, not waterproof; comes in two standard weights (15 pounds or 30 pounds)

Asphalt-saturated felt is the traditional type of roofing underlayment. It is made of a felt paper saturated with asphalt, providing a basic level of waterproofing. It is a relatively inexpensive option and is suitable for roofs that do not require a high level of waterproofing or durability.

Rubberized Asphalt

Best for: Premium roofing protection, leak prevention, and extreme temperatures
Key characteristics: Waterproof; self-adhering and self-healing; patchable; great for variable climates

Rubberized asphalt is a top-quality roofing underlayment that provides the highest level of waterproofing. It is made of a blend of rubber polymers and asphalt, creating a durable and flexible material. Rubberized asphalt underlayment is self-adhering, making it easy to install and providing a tight seal against moisture. It is also self-healing, meaning that it can repair small punctures or tears over time.

Synthetic

Best for: Durability, tear-resistance, and mold-resistance
Key characteristics: High heat tolerance, recyclable, goes on fast, easy to walk on, reliably water-resistant

Synthetic roofing underlayment is the newest type on the market. It is made of woven or spun polyethylene or polypropylene, providing exceptional durability and tear resistance. Synthetic underlayment is also water-resistant, mold-resistant, and has a high heat tolerance. It is a good choice for roofs that require a high level of protection from the elements.

Choosing the Right Roofing Underlayment

The best type of roofing underlayment for your home will depend on several factors, including:

Climate: Rubberized asphalt is the best choice for extreme temperatures, while asphalt-saturated felt is suitable for more moderate climates. Synthetic underlayment is also a good option for variable climates.
Type of Roof: Rubberized asphalt and asphalt-saturated underlayment are suitable for asphalt shingles, slate, and tile roofs. Synthetic underlayment is recommended for metal roofs due to its heat resistance.
Durability: Synthetic underlayment offers the highest level of durability and tear resistance. Rubberized asphalt is also durable and can be patched if damaged.
Water Resistance: Rubberized asphalt provides the best waterproofing, followed by synthetic and then asphalt-saturated felt.
Cost: Asphalt-saturated felt is the most affordable option, followed by synthetic and then rubberized asphalt.

Installation

Proper installation is crucial for the effectiveness of roofing underlayment. Always follow the manufacturer’s instructions for installation. In general, roofing underlayment should be installed in horizontal rows, starting at the bottom of the roof and overlapping each row by at least 4 inches. The underlayment should be secured with roofing nails or staples.

Maintenance

Roofing underlayment typically requires minimal maintenance. However, it is important to inspect the underlayment periodically for any damage or deterioration. If any damage is found, it should be repaired or replaced immediately to prevent moisture from penetrating the roof.

Additional Tips

Ensure that the roof deck is clean and dry before installing roofing underlayment.
Use a high-quality roofing underlayment that is appropriate for your climate and roof type.
Install the underlayment correctly according to the manufacturer’s instructions.
Inspect the underlayment regularly for any damage or deterioration.

Keira

Keira is a seasoned gardener with a rich background in education and a passion for transforming even the smallest, most challenging spaces into lush, productive gardens. With over two decades of experience in both teaching and gardening, she brings a unique blend of skills and insights to Life Science Art, where she shares her expertise through engaging and informative articles. Keira's journey into gardening began in her early years, inspired by her grandmother's ability to coax vibrant blooms and hearty vegetables from the rocky soil of their family farm. This early exposure to the wonders of gardening planted a seed of curiosity and love for plants that has only grown over the years. Before fully immersing herself in the world of gardening, Keira spent many years as a special education teacher. This role honed her patience, creativity, and problem-solving skills—qualities that have proven invaluable in her gardening endeavors. Her teaching experience also gave her a deep understanding of the diverse needs and capabilities of individuals, which she now applies to helping others learn to garden effectively, regardless of their starting point. Keira specializes in small-space gardening, low-income gardening, and cultivating plants in poor soil conditions. She understands that not everyone has access to vast, fertile lands or unlimited resources, and she is dedicated to making gardening accessible and rewarding for everyone. Living in urban areas or having limited outdoor space shouldn't be a barrier to enjoying the benefits of gardening. Keira has mastered the art of maximizing every inch of available space, whether it's a tiny balcony, a cramped backyard, or a window sill. Her innovative techniques and creative solutions help her readers grow a variety of plants in the most confined spaces. Keira is also a strong advocate for low-income gardening. She believes that everyone should have the opportunity to grow their own food and enjoy the therapeutic benefits of gardening, regardless of their financial situation. Through her articles, she shares practical tips on budget-friendly gardening methods, repurposing household items, and making the most of available resources. Her advice empowers individuals and families to start and maintain gardens without breaking the bank. Not everyone is blessed with rich, loamy soil. Keira's expertise extends to growing plants in less-than-ideal soil conditions. She provides guidance on improving soil quality, selecting hardy plant varieties, and employing sustainable practices to ensure a bountiful harvest, even in challenging environments. Her hands-on experience and proven techniques help gardeners turn even the poorest soil into a thriving garden. Keira's contributions to Life Science Art are invaluable. Her articles cover a wide range of topics, from step-by-step guides on planting and maintaining specific types of gardens to tips on dealing with common gardening challenges. She also delves into the science behind plant growth, soil health, and sustainable gardening practices, making complex concepts accessible to readers of all backgrounds. Beyond her technical expertise, Keira's writing is infused with warmth and encouragement. She understands that gardening is not just about growing plants; it's about fostering a connection with nature, finding peace and fulfillment, and building a community. Her personal anecdotes and down-to-earth advice resonate with readers, inspiring them to embark on their own gardening journeys with confidence and joy. Keira invites you to join her on Life Science Art, where she shares her wealth of knowledge and passion for gardening. Whether you're a seasoned gardener or just starting out, her articles offer valuable insights, practical tips, and the inspiration you need to create your own green oasis. Discover the joys of gardening with Keira as your guide and unlock the potential of your outdoor space, no matter how small or challenging it may be.