Underlayment Options for Asphalt Roofs

[DarkKnight]

Hey everyone!

How effective are different underlayment types, like synthetic versus felt, at preventing moisture intrusion under asphalt shingles, especially in areas with frequent wind-driven rain?

[Alpha]

Both synthetic and felt underlayments can help with moisture protection, but synthetic usually does a better job, especially in areas with a lot of wind-driven rain. It’s more durable, resists tearing, and sheds water more effectively. It also stays more stable over time, even if the shingles aren’t installed right away.

Felt, especially the heavier #30 type, can still be useful, but it’s more prone to wrinkling and doesn’t hold up as well if it gets wet. For harsher weather conditions, synthetic is generally the better and more reliable choice.

[DarkKnight]

Thanks! Do you still need ice and water shield if you’re already using a high-quality synthetic underlayment?