Storm Or Hail Damage? We Can Help! Learn More About Our Emergency Storm Services & Call Now For Relief.

Storm Or Hail Damage? We Can Help! Learn More About Our Emergency Storm Services & Call Now For Relief.

Why Roof Underlayment Is A Must Have For Every Homeowner

Posted on September 20, 2023

Why Roof Underlayment Is A Must Have For Every Homeowner

Your roof serves as your home’s defense against the elements. However, in the event that the roofing material becomes compromised, the roof underlayment steps in to protect your home.

An underlayment is a water-resistant sheet that is installed on the roof deck. Its main purpose is to shield your house from weather-related damage and potential fire hazards. Without this barrier, your home could be vulnerable to water infiltration, mold growth, and other issues.

In this article, we will delve into the details surrounding roof underlayments, including what they are and how they function, the various types available, how to choose the appropriate option for your specific needs, and valuable tips for proper installation and maintenance.

By following these guidelines you will be able to choose and install the perfect underlayment for your home.

What Is Underlayment and Why Is It Important?

Underlayment is a layer installed on the roof deck, beneath the shingles, tiles, or metal panels. It acts like an umbrella shielding your roof from rain, snow, and ice.

Underlayment is an important roofing component that plays a role in stopping leaks. If your roofing material is damaged, the underlayment acts as a barrier preventing water from entering your home. Additionally, underlayment helps prevent mold growth and provides insulation for your home. Not only that, it can also extend the lifespan of your roof by up to 20 years.

Moreover, investing in high-quality underlayment can enhance your home’s resale value if you decide to move.

The Benefits Of Installing Roof Underlayment

Now, let’s see a few of the benefits of using underlayment:

1. Waterproofing:

The underlayment serves as a barrier against water infiltration. If severe weather damages your shingles or tiles, the underlayment prevents water from seeping into your home. This effectively safeguards both your roof and the interior of your house, saving you from major repairs.

2. Mold Prevention:

Damp environments can foster the growth of mold and mildew. Without underlayment, moisture can penetrate your roof creating an environment for mold to thrive. Mold infestation can lead to structural problems, allergies, and various health issues.

3. Insulation:

Additionally, underlayment contributes to insulation within your home. A layer of insulation beneath the roof enhances interior comfort levels and boosts energy efficiency. Consequently, you can enjoy your home while reducing utility expenses.

4. Fire resistance:

Some types of underlayment possess fire-resistant properties. In case of a fire, this feature helps safeguard your home by minimizing the risk of damage.

5. Combatting Ice Dams:

If you live in an area where ice dams are common, it is important to have a good quality underlayment installed on your roof. This will help to protect your home from water damage and other problems caused by ice dams.

Different Types Of Roof Underlayment

There are many types of underlayment to choose from, and below we’ll cover three main types:

1. Traditional Asphalt-Saturated Felt

Precision 17

This is a water-resistant underlayment made from either asphalt-saturated paper or fiberglass. It comes in two thicknesses: #15 and #30. The #30 variant is generally stronger and more resistant to damage during installation and severe weather conditions. It works best with asphalt shingles.

2. Synthetic Underlayment

Precision 18

Made from materials like fiberglass or polypropylene, synthetic underlayment is lightweight, tear-resistant, and provides protection against water. The manufacturing process may vary across brands, which can affect its performance. Therefore it is important to do research and consult a contractor to choose the right materials for your home. 

3. Rubberized Asphalt Underlayment

Precision 19

Although it may be more expensive, rubberized asphalt underlayment offers the best solution for preventing leaks. It consists of a blend of asphalt and rubber polymers, and self-adheres to the roof deck creating a seal. Its durability allows it to expand and contract without being damaged, making it an ideal choice for slate shingles.

How To Choose The Right Roof Underlayment For Your Home

Choosing the right underlayment can be difficult due to the variety of options available on the market. However, consider these factors to make the right choice for your specific needs.

Factor 1: Roof Slope

First and foremost, roof slope is key in selecting underlayment. Steep roofs require slip-proof materials like rubberized asphalt. For low-slope or flat roofs, synthetic underlayment is suitable as it resists ponding water.

Factor 2: Climate

Secondly, select a durable, weather-resistant underlayment, like a synthetic underlayment, for areas with tough weather. It’s tear-resistant and withstands extreme temperatures.

Factor 3: Lifespan

If you’re looking for a temporary roofing solution, felt paper could be suitable. For a long-lasting choice, synthetic underlayment is recommended, as it lasts up to 40 years.

Factor 4: Local Building Codes and Warranties

Additionally, it’s also important to consider local building codes and warranties when choosing underlayment. Some types of roofing materials may require installation over specific types of underlayment for the warranty to remain valid.

Here are some additional tips:

  • If you’re unsure which type of roof underlayment is right for your home, talk to a professional roofing contractor.

  • Always follow the manufacturer’s instructions carefully when installing roof underlayment.

  • Make sure to store the underlayment in a cool, dry place until you’re ready to install it.

How To Install Roof Underlayment

Installing underlayment is an important part of protecting your home from the elements. It helps to keep water out and prevent leaks, which can cause serious damage to your roof and home interior.

Tools and Materials:

  • Underlayment 
  • Roofing nails
  • Nail gun
  • Utility knife
  • Flashing tape or caulk

Installation Instructions:

  1. First, clear the roof of any debris and old roofing material.

  2. Measure and cut the underlayment material to fit the dimensions of your roof.

  3. Next, start at the bottom edge of your roof and lay the underlayment horizontally, overlapping each layer by at least 6 inches.

  4. Nail down the underlayment using a nail gun.

  5. Continue laying and nailing down the underlayment until you reach the top of the roof.

  6. Finally, seal around vents and chimneys with flashing or caulk to prevent leaks.


  • Use a nail gun to secure the underlayment. This is more accurate and efficient than using a hammer.

  • Properly space the nails about 6 inches apart. This will ensure that the underlayment is securely fastened to the roof deck.

  • If you are unsure about how to install an underlayment or if you don’t have the necessary tools and experience, it is best to hire a local roofing company.

Common Mistakes To Avoid When Installing Roof Underlayment

While adding that extra layer of defense to your house can be a rewarding DIY project, there are a few common mistakes you’ll want to steer clear of. One such error is not taking the time to properly prepare the roof deck before starting the underlayment installation. If there are old nails or other debris left on the surface, they can puncture your new underlayment and create potential leak points. Always clean and inspect your roof deck for any damage before beginning the installation.

Another mistake many homeowners make is overlapping the underlayment in the wrong direction. The correct method is to start at the bottom of the roof and work your way up, ensuring that each new layer overlaps with one below it. This ensures that water will flow down without getting trapped underneath subsequent layers, ultimately protecting your home from potential water damage.

And remember, never rush through this process – patience and attention to detail can save you from costly repairs down the line.

Tips For Maintaining Your Roof Underlayment

Preserving the quality of your roof underlayment ensures the longevity of your roofing system. Consider these maintenance tips:

  • Inspect your roof regularly and clean it when needed.

  • Moreover, trim any trees or shrubs that are close to your home.

  • Have your roof inspected by a qualified roofing contractor at least once a year.

  • If you live in an area with severe weather conditions, you may need to have your roof inspected more often.

  • Also, if you are planning to have your roof repaired or replaced, it is a good idea to replace your underlayment at the same time.

Here are a few additional tips:

  • When inspecting your roof, look for any signs of moisture damage.

  • If you are cleaning your roof yourself, be careful not to damage the underlayment.

  • When trimming trees or shrubs, be careful not to let branches fall on the roof.

By following these tips, you can keep your roof underlayment in good condition and extend its lifespan.

Summing  Everything Up

Roof underlayment is an important part of your roofing system. It protects your home from the elements and extends the lifespan of your roof. Selecting and maintaining the right underlayment is crucial for the best home protection. 

If you are looking for a professional roofing company in Pataskala, Ohio, look no further than our team at Bristlewood Roofing & Remodeling. With years of experience, we can help you inspect your roofing system and suggest the best underlayment for your home. 

Moreover, we can also help you replace or install a new underlayment. Remember, a well-maintained roof keeps your home safe and secure. So, give us a call today at (614) 307-5881!