Black Felt Roofing Paper: A Practical Guide for Shingle Roofs

Black felt roofing paper, also known as tar paper or asphalt-saturated felt, is a foundational layer in many traditional shingle roof assemblies. This guide explains what black felt roofing paper is, the different types and grades, installation basics, benefits and limitations, maintenance tips, and how to choose the right product for U.S. rooftops. Readers will learn how this material contributes to moisture protection, roof durability, and overall cost efficiency when used correctly.

What Is Black Felt Roofing Paper?

Black felt roofing paper is a lightweight, asphalt-saturated fabric designed to act as a secondary weatherproof layer beneath shingles. It is produced from organic or fiberglass mat coated with asphalt, giving it flexibility, water resistance, and tear strength. In many older and some newer installations, this layer serves as a temporary or permanent underlayment that helps shed moisture during rain and protects the roof deck before shingles are laid. Its black color is characteristic of asphalt-saturated products and helps hide imperfections beneath the final roofing surface.

Types And Grades

Roofing felt comes in several varieties, with the most common being organic (paper) and fiberglass-based products. Organic felt is made from wood pulp and provides good nail-holding capacity but can degrade faster in prolonged moisture. Fiberglass felt uses glass fibers and offers greater tear strength and dimensional stability with improved fire resistance. Common weight options include 15 lb, 30 lb, and 40 lb per 100 square feet, though some regions use equivalent metric ratings. In modern U.S. roofs, 15 and 30 lb felt are frequently used, while higher grades may be reserved for specific climate conditions or code requirements. A newer alternative is synthetic underlayment, which provides similar moisture protection with higher durability, but many projects still rely on traditional black felt for its cost efficiency and familiarity.

Installation Basics

Proper installation of black felt roofing paper is essential for effective performance. Start by inspecting the roof deck for damage and ensure clean, dry conditions before applying the underlayment. Roll out the felt horizontally from eave to ridge with a slight overhang over the drip edge, typically 4 to 6 inches. Each row should be lapped by at least 2 to 4 inches to ensure overlap and water shedding. Secure with corrosion-resistant staples or roofing nails, placing fasteners about 6 to 8 inches apart in the field and 3 to 4 inches from the edges. At rake edges, open valleys, and around chimneys or penetrations, ensure proper cuts and additional folds to maintain a continuous barrier. Do not install over wet or damp surface, and avoid walking on exposed felt to minimize tearing.

Benefits And Limitations

Benefits include an extra layer of moisture protection, improved shingle alignment, and a buffer against minor roof deck imperfections. It can simplify installation and improve long-term durability when paired with modern shingles, especially in areas with moderate weather. Limitations include reduced effectiveness in extreme heat or prolonged sun exposure, potential rapid deterioration if moisture penetrates, and a perception of being obsolete in regions with access to high-quality synthetic underlayments. In some U.S. markets, building codes are shifting toward synthetic or rubberized underlayment, so homeowners should verify local code requirements before choosing black felt.

Maintenance And Safety

Maintenance is generally minimal once the roof is installed correctly. Inspect the roof after severe weather for lifted edges, tears, or exposed sections, and repair promptly to prevent moisture intrusion. Keep gutters clear so that water can drain away and does not back up onto the underlayment. For safety, wear appropriate footwear and avoid working on steep pitches without proper fall protection. When replacing or repairing shingles, ensure the underlayment remains intact and inspect for any compromised areas that may require resealing or reapplication.

Choosing The Right Felt For Your Roof

To select the appropriate black felt roofing paper, consider climate, roof pitch, and local building codes. In hot, sunny climates, UV exposure can degrade felt more quickly, making higher-quality or synthetic alternatives appealing. For wet or mixed climates, a felt with thicker weight and robust tear resistance can offer better protection during construction and in the maintenance phase. Always check the current local regulations and manufacturer specifications for weight, material composition (organic vs fiberglass), and compatibility with your chosen shingles. If in doubt, consult a licensed roofing professional who can tailor the underlayment choice to your home’s design and climate.