Underlayment, like felt paper, acts as sheathing between the roof deck and any humidity that creeps beneath the shingles. If you live in a chilly local climate, you may have an additional barrier to prevent ice dams from forming in Wintertime. This barrier is often sold as self-adhesive sheeting that https://www.furniturelb.com/tips-for-choosing-the-best-roofing-company-in-carol-stream-il-expert-advice-for-homeowners/