Underlayment's should be used with which type of covering?

Underlayment is a critical component in roofing systems, especially for steep-slope coverings. It serves several purposes, including providing an extra layer of protection from water infiltration, acting as a moisture barrier, and acting as a slip-resistant surface for workers during installation.

When using steep-slope coverings—which include materials like asphalt shingles, metal roofs, clay tiles, and others—underlayment is essential. The steep slope angles can lead to water running quickly off the roof, but in certain conditions, water can still seep under shingles or tiles. The underlayment helps manage this potential water intrusion.

In contrast, while asphalt shingles and other specific materials may have unique requirements or recommendations regarding underlayment, the universal guideline is that any steep-slope roofing system should utilize it. This ensures enhanced performance and longevity, making it a best practice across the board rather than limiting it to specific types of roofing materials.