Advancements in asphalt shingles enables them to last longer today than ever before. One problem that can call for premature shingle replacement is the underlayment. The average felt underlayment has the potential to absorb moisture, which can damage the roof deck. Subsequently, moisture can cause the underlayment to swell, which can telegraph to the shingles, creating a roof that appears warped or wrinkled.
Over time, roofing felts can become brittle and more prone to cracking and failure before the shingles need to be replaced. Roofing felts are also weaker than high-performance underlayments and can easily be damaged during installation as roofers walk on the unprotected felts.