Asphalt-Saturated Felt Underlayment: What You Need to Know
Roof underlayment can be made of asphalt-saturated felt, rubberized asphalt or non-bitumen synthetic. Asphalt-saturated felt is perhaps the most popular choice. It is one of the most common underlayments used by residential roofers and can consist of either an organic or fiberglass substrate. Of the two, organic, having a cellulose base, is much more common.
