Key Questions Homeowners Should Ask Their Roofing Contractor About Tile Underlayment Installation

When installing or replacing the underlayment of a tile roof, it's crucial to ensure that every aspect of the job is performed to the highest standards. Many homeowners believe that their tile roof will last a lifetime, but the reality is that the tiles themselves may last 50 years or more, while the underlayment—the actual waterproofing layer—often needs replacing after 15-20 years. To avoid costly leaks and damage, it's important to ask the right questions when hiring a roofing contractor. Here are the key questions every homeowner should ask, along with recommendations from the Tile Roofing Institute.

1. How Far Do You Overlap the Underlayment?

One of the most important technical questions you can ask is about the overlap of the underlayment. The underlayment acts as a barrier to water, and how it is layered determines how well it will protect your home.

• Why It Matters: Some contractors may only overlap the underlayment by a few inches, which meets basic code but can cause problems in the future. Over time, the edges of the underlayment can curl up, allowing water to penetrate.
• Tile Roofing Institute Recommendation: The Tile Roofing Institute recommends overlapping the underlayment by at least half its width, creating a "double underlayment" effect. This method ensures that even if one layer is compromised, the other layer remains intact, offering superior protection.

2. What Type of Underlayment Do You Use?

The type of underlayment used is a critical factor in determining the longevity of your roof, especially in Arizona's hot climate. Traditional felt underlayment was once the standard, but advancements in materials have provided more durable options.

• Why It Matters: The hot Arizona sun can quickly deteriorate low-quality underlayment, leading to early leaks and costly repairs.
• Tile Roofing Institute Recommendation: The Tile Roofing Institute suggests using SBS-modified bitumen felt underlayment in hot and dry climates like Arizona. This type of underlayment is reinforced with rubber to self-seal around nails and other penetrations, providing superior waterproofing. The self-seal is very important, as it creates a strong seal between the nails and the surface; whereas others leave a small hole because the surface doesn't close around the nail. It can handle the heat better and lasts up to 20-30 years.

3. How Do You Handle Roof Penetrations Around Chimneys and Vents?

Chimneys, vents, skylights, and other penetrations are common weak points on a roof. Improper sealing in these areas can lead to significant water damage over time.

• Why It Matters: These areas are prone to leaks, especially if not sealed with high-quality flashing and underlayment.
• Best Practice: Make sure your contractor uses specialized flashing and reinforces it with a self-adhering underlayment around all penetrations to create a watertight seal. A high-quality SBS-modified bitumen underlayment, as recommended by the Tile Roofing Institute, is ideal for sealing around roof penetrations.

4. How Do You Tie Into Other Roof Surfaces?

If your home has different roofing materials, such as transitioning from a tile roof to a foam or flat roof, the connection points between the two must be watertight to prevent leaks.

• Why It Matters: Different roofing materials expand and contract at different rates, making these transition points vulnerable to leaks.
• Best Practice: Contractors should use transition flashing and integrate both roofing systems carefully. The Tile Roofing Institute recommends using a combination of high-quality underlayment and flashing to create a seamless connection between the materials, ensuring long-lasting waterproofing.

5. What Is Your Process for Ensuring the Roof Is Completely Watertight?

It's important to ask your contractor about their overall process for ensuring that your roof will be fully watertight, especially in areas prone to water penetration.

• Why It Matters: Even a small oversight in installation can result in costly water damage.
• Best Practice: The contractor should follow Tile Roofing Institute guidelines by using double layers of underlayment in high-risk areas like valleys and along the roof's edge. These areas are where water tends to collect, and a double layer of SBS-modified underlayment ensures that even in the event of a failure in one layer, the second layer will still provide protection​.

6. Do You Offer a Warranty or Follow-Up Inspections?

The final question to ask is whether your contractor offers a warranty or conducts follow-up inspections to ensure the roof remains in good condition.

• Why It Matters: Even the best installation can experience wear and tear over time, especially in Arizona's extreme climate.
• Best Practice: Contractors should provide a warranty on both the materials and workmanship. Some may even offer yearly inspections, which can catch minor issues before they become major problems​.

Tile roofs can last a lifetime, but only if the underlayment—the critical waterproofing layer—is properly installed and maintained. Asking the right questions and choosing a contractor who follows the Tile Roofing Institute’s best practices can ensure your roof performs optimally for decades. By investing in quality materials like SBS-modified bitumen underlayment and ensuring proper installation, you can prevent leaks, avoid costly repairs, and protect your home for years to come.

Ready to protect your tile roof? Contact TraVek Roofing today at 0480-367-1171 to discuss your underlayment needs and ensure your roof is built to last in Arizona’s harsh climate.