If underlayments could talk: which one would outlast the others?

- I’ve actually seen felt last longer than expected in some cases, especially on older homes with good attic ventilation. Not every felt job fails early—sometimes it’s the install, not the material.
-

“My experience is that synthetics cut down on emergency repairs, but you’re paying more up front and maybe not seeing the savings until year 7 or 8.”

That lines up with what I’ve seen, but only if the synthetic is installed right. I’ve inspected a few roofs where cheap synthetics tore at fasteners or degraded from UV before shingles went on.
- Warranties are a headache. Some shingle brands are super strict about underlayment type, but others don’t care as long as it’s code-compliant. Always worth double-checking before you buy.
- For short-term holds or flips, I still see felt as a reasonable choice. If you’re planning to keep the building long-term, synthetic probably makes more sense—but only if you trust the installer to do it right.