10/30/2026
Roof underlayment, the eave layer, the wood deck: most of a roof is out of sight once the shingles go on.
A shingle roof is built in layers, from the wood up:
The deck. Wood sheathing gives everything above it something solid to fasten to.The eave. The lower edge of the roof often gets its own layer. In areas with a history of ice forming along the eaves, an ice barrier is typically installed at the roof edge.Underlayment. Shingles are the main barrier against water. Underlayment is the second one, there for water that gets past them, like wind-driven rain or meltwater backing up in winter.Shingles. They go on last, each course overlapping the one below so water runs down and off.Caps. Shaped cap shingles close the hips and ridge, where roof planes meet.
Tip: when you compare roof quotes, ask what goes down before the shingles and what’s used along the eaves. Two quotes can look alike on the surface and differ underneath.
Questions about what goes under your roof? Visit novalisroofingandsiding.com or call (973) 635-1165.