How Much Roof Coating Should I Use On My Roof?

Tile roofs are one of the most durable and attractive roofing systems for Tucson homes, often lasting 50 years or more. But while the clay or concrete tiles themselves can last decades, the underlayment beneath them is the true workhorse. This layer is what keeps water out, protects the roof deck, and ensures the tiles do their job. When the underlayment fails, leaks begin—often long before the tiles show visible wear.

For any homeowner working with a Tucson roofing company on a tile roof replacement, choosing the right underlayment is critical. Modern synthetic options such as Polyglass TU-Max and Poly-Tech XPU offer major advantages over outdated 30- or 40-lb felt paper. Below, we’ll explore why underlayment matters, and compare TU-Max vs. XPU so you can make an informed decision with your roofer.

Why Synthetic Underlayment is Essential for Tucson Tile Roofs

The desert climate puts extreme stress on roofing systems. Tile roofs in Tucson face:

• Intense UV exposure that quickly breaks down asphalt-based felt paper.
• High heat cycles that cause expansion and contraction.
• Monsoon storms that deliver heavy rains and micro wind bursts that can cause tiles to be lifted off your roof.

Because of these conditions, most traditional roof paper fails in 15–25 years, even if the tiles themselves look fine. A reputable roofing contractor in Tucson will almost always recommend replacing the underlayment when doing a tile roof replacement.

Comparing Two Leading Synthetic Underlayments

There are numerous synthetic underlayment options for home owners.  Those homeowners who want to completely ensure their home is protected for the longest periods of time, there are two primary options: Polyglass TU-Max and Poly-Tech XPU.  Until this year there was truly only one option but Poly-Tech released its 50-year peel and stick underlayment that has become a direct competitor to TU-Max.  Both underlayments are well worth using and both have their pros and cons.

Polyglass TU-Max

Polyglass TU-Max is a high-performance, SBS-modified bitumen underlayment designed specifically for tile roofs, especially in high-heat conditions. It combines asphalt with polymers, creating a durable, flexible sheet.

Pros:

• Excellent waterproofing due to SBS-modified bitumen.
• Self-healing around fasteners, reducing leak risk.
• Strong adhesion to the roof deck.
• Proven track record in desert environments.
• 30-Year Warranty.

Cons:

• Heavier than some other synthetics.
• Typically rated for 30 years, not lifetime.

TU-Max is a solid choice if you want a dependable, well-tested underlayment that balances cost with performance. Many Tucson roofers trust TU-Max for its reliability in the desert climates.

Poly-Tech XPU

Poly-Tech XPU is a synthetic, peel-and-stick underlayment built with advanced polymers. It’s engineered to withstand longer lifespans and more extreme conditions than traditional asphalt-based products.

Pros:

• Self-healing around fasteners, reducing leak risk.
• 50-year rated product, designed to outlast most roof systems.
• Exceptional UV resistance, ideal for Arizona’s sun exposure.
• Lighter weight which makes it easier to install.
• Adheres very quickly to roof deck.

Cons:

• Higher upfront cost compared to TU-Max.
• Much stickier which requires a more careful installation.

For homeowners seeking the longest-lasting solution for a tile roof replacement, XPU is quickly becoming the gold standard. Many forward-thinking roofing companies in Tucson prefer XPU for its durability and longevity.

Which Underlayment is Right for You?

Replacing the underlayment on a tile roof is not optional—it’s essential for the long-term performance of your roofing system. Both Polyglass TU-Max and Poly-Tech XPU are excellent modern solutions that far outperform outdated felt paper. TU-Max offers a strong balance of cost and reliability, while XPU delivers unmatched longevity and heat resistance for Tucson’s unique climate. You cannot go wrong with either of these choices.

The decision often comes down to budget vs. lifespan:

• TU-Max: Excellent performance, lower cost, 30-year rating.
• XPU: Higher upfront investment, but superior long-term protection with a 50-year rating.

A trustworthy Tucson roofer will explain both options and provide clear estimates. While TU-Max is a reliable, proven choice, XPU often delivers the best value over time, especially if you plan to live in your home for decades.

Work With a Tucson Roofing Company Experienced in Tile Roofs

Tile roof replacements are highly specialized projects. They require careful tile removal, removal of the old underlayment and battens, inspection of the wood decking and replacing rotted wood as needed, reinstallation of the new underlayment and battens, and reinstallation of the tiles.  This is an arduous process so it is important to choose your contractor wisely.  Working with a certified, experienced roofing contractor in Tucson ensures:

• Proper installation of TU-Max or XPU according to manufacturer specifications.
• Identification of hidden damage to decking, valleys, or battens.
• Ensuring proper roofing codes are followed.
• A warranty that protects your investment from a roofing contractor that will honor the warranty.

Why Choose Desert Sky Roofing?

Finally, why choose us?  Choose Desert Sky Roofing for your roofing needs because we truly care about you and your roof.  We want to provide the best solution for you. We will never sell you something you do not need and we will ensure your roof is repaired properly and up to code.  If you want a roofing company that will do it right the first time, give us a call!