Roof installation showing ice and water barrier and synthetic underlayment Choosing the right roof underlayment is a critical step in any roof replacement or new roofing project, especially for steep slope roofing common in Michigan. The underlayment acts as a protective barrier beneath the shingles or tiles, shielding your home from water infiltration, ice dams, and wind-driven rain. With several options available—felt paper, low-grade synthetic underlayment, high-grade synt
