Underlayment sits directly on top of the roof deck and below shingles or another finished roofing material. It provides a secondary layer of protection when water gets past the outer roof covering.
Why It Matters
Good underlayment helps protect the home during wind-driven rain, snow, and installation transitions. It is especially important in valleys, along eaves, around penetrations, and anywhere water is more likely to collect.
Common Problems
Underlayment problems can include torn material, improper overlaps, missed fasteners, poor integration with flashing, or using the wrong product for vulnerable areas of the roof.
Exterior Echelon Notes
Exterior Echelon reviews underlayment as part of the full roof system, especially where it connects with drip edge, valleys, flashing, and ice-dam protection.
