What Is Roof Underlayment? A Guide by Tip Top Roofing Service in Scottsdale
When most people think about a roof, they picture the outer layer — shingles, tiles, or metal. But there’s a hidden layer underneath that plays a critical role in protecting your home, especially in Scottsdale’s extreme weather.
That layer is called roof underlayment, and at Tip Top Roofing Service, we believe every homeowner should understand how it works. Whether you’re planning a roof replacement or just doing your research, this guide will help you make smarter choices.
What Is Roof Underlayment?
Roof underlayment is a moisture-resistant or waterproof barrier installed between your roof decking and the final roofing material (such as shingles or tiles). Though it’s invisible once installed, it acts as a secondary line of defense against water leaks, wind-driven rain, and heat intrusion.
In Scottsdale, this extra protection is vital. Monsoons, high UV exposure, and sudden temperature swings can all damage roofs. If your top layer fails, the underlayment helps prevent water from reaching your attic or structural framing.
Why Roof Underlayment Matters in Scottsdale
Here’s how roof underlayment protects your home:
| Benefit | What It Does |
|---|---|
| Water Barrier | Prevents leaks from rain and monsoons |
| Heat Shield | Reduces attic heat and improves energy efficiency |
| Dust Protection | Seals small gaps to block dust and debris |
| Emergency Backup | Protects when shingles or tiles are damaged |
Without a reliable underlayment, even a minor crack in your roof could lead to mold, wood rot, or ceiling stains — problems we see too often during free roof inspections.
3 Main Types of Roof Underlayment We Recommend
Depending on your roofing material, slope, and budget, Tip Top Roofing offers three common types of underlayment:
1. Asphalt-Saturated Felt
One of the oldest materials used, this underlayment is made from organic fibers or fiberglass soaked in asphalt.
| Pros | Cons |
|---|---|
| Budget-friendly | Less durable in high heat |
| Readily available | Can wrinkle or tear |
| Works on steep roofs | Not fully waterproof |
Best for basic roof projects or temporary solutions.
2. Synthetic Underlayment
Made from polypropylene or polyethylene, synthetic underlayment is preferred for most modern homes in Arizona.
| Pros | Cons |
|---|---|
| Tear-resistant | Higher cost than felt |
| UV-resistant | Less breathable than felt |
| Lightweight for faster installation | Quality varies by brand |
We frequently use synthetic underlayment during roof installation for its superior durability and weather performance.
3. Peel & Stick (Rubberized Asphalt)
This self-adhesive underlayment bonds directly to the decking for maximum waterproofing, especially in high-risk areas like roof valleys, chimneys, and skylights.
| Pros | Cons |
|---|---|
| Fully waterproof | Most expensive option |
| Seals around nails | Difficult to reposition once applied |
| Ideal for tricky roof zones | Usually used in sections, not full coverage |
Ideal for Scottsdale’s monsoon season and homes with complex rooflines.
What Is Peel & Stick Underlayment?
Peel & Stick is a rubberized layer with a sticky backing that eliminates the need for nails or staples. It’s commonly applied to:
- Roof edges
- Valleys
- Around vents and skylights
- Flat or low-slope sections
At Tip Top Roofing Service, we often combine Peel & Stick with synthetic underlayment to maximize durability where it’s needed most.
How We Install Underlayment (Step-by-Step)
Here’s a quick look at how our certified team installs your underlayment:
- Inspect & clean the deck – We check for damaged wood or weak spots.
- Roll out underlayment – Starting from the bottom, overlapping rows to shed water.
- Secure – Fasteners are added (except for Peel & Stick, which adheres on its own).
- Add extra layers – In valleys or around chimneys, we apply multiple protective layers.
Every roofing project in Scottsdale gets our full attention to detail to ensure long-lasting performance.
When Should You Replace Roof Underlayment?
Underlayment wears out over time, even if your shingles still look fine.
| Situation | Why You Should Replace It |
|---|---|
| Full roof replacement | Ideal time to install new underlayment |
| Shingles look fine, but there are leaks | Likely the underlayment is damaged |
| Roof is over 15 years old | Especially if using older felt underlayment |
If you’re not sure, a free inspection can confirm its condition.
Best Underlayment for Scottsdale Homes
Given our weather extremes, here’s what we typically recommend:
| Material | Why It Works in Scottsdale |
|---|---|
| Synthetic | Withstands UV and high heat, doesn’t tear easily |
| Peel & Stick | Great waterproofing for vulnerable areas |
| Asphalt Felt | Less effective in long-term Arizona heat exposure |
We tailor every recommendation during your roofing consultation to suit your home’s slope, material, and exposure.
Building Code Compliance in Arizona
Your underlayment must meet local and national standards. At Tip Top Roofing, we use only code-compliant products:
| Standard | Applies To |
|---|---|
| ASTM D226 / D4869 | Asphalt-saturated felt |
| ASTM D1970 | Peel & Stick underlayment |
| UL Class A Fire Rating | High heat and fire resistance |
These certifications ensure your roof is legally safe and insurable in Scottsdale.
Why Homeowners Trust Tip Top Roofing
We aren’t just about quick fixes — we build roofs to last in Scottsdale’s extreme conditions. Our commitment to quality materials, precise workmanship, and honest communication sets us apart.
Whether you’re replacing old underlayment or planning a full roof upgrade, our team is here to guide you.
Book Your Free Roof Inspection
Concerned your underlayment might be failing? Let’s find out — before it leads to leaks or mold. At Tip Top Roofing Service, we offer free roof inspections with zero pressure and clear results.
👉 Call (480) 877‑1643 or
👉 Book Online Now
FAQs About Roof Underlayment in Scottsdale
| Question | Answer |
|---|---|
| What does roof underlayment do? | Protects your home from moisture, dust, and heat under the main roof. |
| Which underlayment is best in Scottsdale? | Synthetic or Peel & Stick for UV and water protection. |
| Can I replace underlayment without removing tiles? | No. Tiles or shingles must be removed first. |
| How much does it cost? | Around $3.50–$6.50 per square foot, depending on material and labor. |
| Is underlayment required in Scottsdale? | Yes, per Arizona building codes. |
| How long does it last? | 15–30 years depending on type and exposure. |
Still have questions? Contact us — we’re here to help!
