What Goes Under Shingles: A Comprehensive Guide


What Goes Under Shingles: A Comprehensive Guide

What Goes Under Shingles A Comprehensive Guide

If you’re a homeowner, you’ve probably heard about the importance of a strong and reliable roof. Your roof is your first line of defense against the elements, and one of the crucial components of any roof is what goes under the shingles.

In this article, we will explore the essential elements that make up the underlayment of your roof and why they are so vital to the overall health and longevity of your roof.

The Role of Roof Underlayment

Before we dive into the specifics of what goes under shingles, let’s discuss the role of roof underlayment. Roof underlayment is a protective layer installed beneath the shingles. It serves multiple critical functions, including:

1. Waterproofing

One of the primary functions of roof underlayment is to provide an additional layer of waterproofing. Shingles can be susceptible to wind-driven rain and snow, and the underlayment acts as a barrier that prevents moisture from seeping into your home.

2. Moisture Control

In addition to waterproofing, underlayment helps control moisture and humidity. It plays a crucial role in preventing condensation in your attic, which can lead to mold and rot.

3. Protection from Ice Dams

In colder climates, ice dams can form on roofs, leading to water infiltration. The underlayment helps prevent this by providing an extra layer of defense against ice and snow.

4. Enhancing Roof Longevity

A well-installed underlayment can significantly extend the lifespan of your roof. It acts as a shield that protects the roof deck from UV rays, which can cause shingles to deteriorate over time.

5. Thermal Insulation

Some underlayment materials offer thermal insulation properties, helping to improve the energy efficiency of your home.


Types of Roof Underlayment

Now that we understand the importance of roof underlayment, let’s explore the various types available:

1. Asphalt-Saturated Felt

Asphalt-saturated felt, also known as roofing felt, is a traditional underlayment material. It is made from a base of cellulose or fiberglass, saturated with asphalt. This type of underlayment is cost-effective and provides good waterproofing.

2. Synthetic Underlayment

Synthetic underlayment is a newer and increasingly popular option. It is made from polyethylene or polypropylene, making it highly resistant to moisture. Synthetic underlayment is lightweight, easy to install, and offers excellent protection against leaks.

3. Rubberized Asphalt

Rubberized asphalt underlayment is a self-adhering material that is highly effective in waterproofing. It is often used in areas prone to high winds and heavy rain. This type of underlayment provides superior protection against leaks and has excellent wind resistance.

4. Peel-and-stick underlayment

Peel-and-stick underlayment is another self-adhering option that is easy to install. It offers superior protection against water infiltration and is commonly used in areas with heavy rainfall and ice dam formation.

5. Insulated Underlayment

Insulated underlayment combines traditional underlayment materials with an added layer of insulation. This type of underlayment helps improve the energy efficiency of your home by reducing heat loss.

Installation and Maintenance

Proper installation and maintenance of your roof underlayment are critical to its effectiveness. Here are some key considerations:

1. Professional Installation

It’s advisable to have your roof underlayment installed by a professional roofing contractor. They have the expertise and experience to ensure it’s done correctly.

2. Regular Inspections

Regularly inspect your roof for any signs of damage or wear to the underlayment. Promptly address any issues to prevent leaks and further damage to your roof.

3. Ventilation

Proper roof ventilation is essential to prevent moisture buildup in your attic, which can affect the underlayment. Ensure your attic is adequately ventilated to maintain the integrity of the underlayment.

4. Replacement

If your roof is being replaced, it’s a good time to assess the condition of the underlayment. Depending on its age and condition, you may need to replace it along with the shingles.


In conclusion, what goes under shingles is a critical component of your roofing system. Roof underlayment serves various essential functions, including waterproofing, moisture control, protection from ice dams, and enhancing the longevity of your roof.

Choosing the right type of underlayment and ensuring proper installation and maintenance are key to a durable and reliable roof. By understanding the role of underlayment, you can make informed decisions about your roofing system and ensure the protection of your home for years to come

Read More: Peel and Stick Roof Underlayment Problems

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