Roofing Staples for Tar Paper: A Practical Guide for American Homes

Tar paper, or roofing felt, remains a common underlayment in many American roofing projects. Choosing the right staples is essential for secure attachment, durability, and ease of installation. This guide explains what to look for in roofing staples for tar paper, how to select the appropriate size and material, and best practices to ensure a long-lasting roof underlay.

Understanding Tar Paper And Staples Compatibility

Tar paper is a lightweight, asphalt-impregnated felt that provides a water-resistant barrier beneath roofing shingles. Its flexibility and texture demand fasteners that hold firmly without tearing the paper. Staples must penetrate the felt without causing excessive weakening or rust over time. If staples are too short or too narrow, they may loosen in wind or during expansion and contraction with temperature changes. In contrast, oversized or overly sharp points can split the paper, reducing its effectiveness.

Material matters. Galvanized steel staples resist corrosion in humid or coastal environments, extending the life of the underlayment. For roofs exposed to heavy moisture or salt spray, stainless steel staples offer superior long-term durability. The crown width and leg length influence hold strength and nailing depth into the roofing deck or sheathing.

Choosing The Right Roofing Staples For Tar Paper

Gauge and length: A common choice is 15- to 16-gauge staples with leg lengths ranging from 1/4 inch to 3/8 inch. For tar paper, a leg length of 1/4 inch is typically sufficient when attaching to an sheathing like plywood or board decking. If the substrate is thicker, or if a more wind-resistant installation is required, 3/8 inch legs provide additional bite.

Crown width: A narrow crown (around 3/16 inch) helps prevent tearing and allows for tight, even rows. Some projects benefit from a wider crown (up to 7/32 inch) for improved holding power, especially in high-wind areas.

Material: Galvanized staples are standard for tar paper, offering reliable rust resistance in typical American climates. Stainless steel staples are preferred in coastal regions or areas with high salinity or harsh exposure. Avoid plain steel staples in damp conditions, as they rust and may stain or degrade the underlayment.

Tip: Choose staples labeled for roofing or outdoor use, and verify they are compatible with the stapler or nailer being used. Some pneumatic tools have specific staple gauges and crown widths.

Installation Tips For Tar Paper With Staples

Proper alignment matters. Start near the lower edge of the roof and work upward, placing staples about every 8 to 12 inches along the felt seams. Along vertical joints, place staples at regular intervals to prevent movement during wind uplift.

Prepare the surface. Ensure the roof deck is clean, dry, and free of debris before applying tar paper. Any moisture or dust can reduce staple grip and lead to loosening over time. If tar paper is oversized or has gaps, trim carefully to avoid exposing the deck.

Tool setup matters. Use a roofing stapler or hammer with a broad, clean stapling face to avoid denting the tar paper. Test a few staples on a scrap piece to confirm the depth and pull resistance before proceeding across the entire area. Maintain consistent staple depth so the crown sits flush with the surface.

Wind considerations. In high-wind zones, follow local code or manufacturer recommendations for fastener density and edge nailing rather than relying solely on staples. For roof edges and eaves, increase fastener frequency to reduce the risk of uplift.

Common Mistakes And Safety

Overdriving staples can tear tar paper and create weak spots. Underdriving leaves staples protruding, which can snag shingles during installation. Always aim for a flush seat with the tar paper without tearing the material.

Assuming staples alone are enough may lead to future problems. Tar paper underlay should be installed with other roofing components in proper sequence, including drip edge and flashing where applicable.

Safety first. Wear eye protection and gloves, and use fall protection when working on sloped roofs. Keep tools organized to prevent accidental foot or hand injuries.

Maintenance, Longevity, And When To Replace

A well-fastened tar paper layer resists wind uplift and water infiltration, extending roof life. Periodic inspection after severe weather helps identify loose or damaged areas. If staples show signs of rust, corrosion, or the tar paper begins to peel near fasteners, replacement may be prudent. Replacing tar paper typically involves removing and re-fastening adjacent sections with fresh staples of the appropriate material and length.

Age and exposure influence decisions. Tar paper that has endured consistent moisture, UV exposure, or mechanical stress may become brittle or lose its adhesive properties. In such cases, re-laying a new underlayment with proper fasteners ensures continued protection.

Choosing A Qualified Installer And Local Codes

Local building codes may specify staple type, size, and spacing for tar paper underlayment. A licensed roofing professional can confirm material compatibility with existing roofing systems and ensure adherence to wind uplift requirements and fire codes.

Key Takeaways For Homeowners

• Opt for galvanized or stainless steel staples designed for roofing underlayment.
• Typical choices: 15–16 gauge, 1/4 to 3/8 inch leg length, narrow crown around 3/16 inch.
• Ensure proper tool compatibility and correct staple depth to avoid tearing or protrusion.
• Follow local codes for staple density, especially in high-wind regions.
• Regularly inspect tar paper after severe weather and replace if damage is evident.