Tar paper, commonly known as roofing felt, remains a foundational underlayment choice for many American roofs. It provides a moisture barrier, helps shed water, and offers a cushion under shingles during installation. As roofing materials evolve, homeowners and professionals look for blends of traditional performance and modern durability. This guide explores the best tar paper options for roofing, factors to consider when choosing underlayment, installation tips, and practical maintenance insights to extend roof lifespan.
What Is Tar Paper And Why It Matters
Tar paper is a moisture-resistant layer installed between the roof deck and shingles. Traditionally made from asphalt-saturated felt, it protects the roof deck from water and wind-driven moisture during construction and in the years before shingles are fully weatherproofed. The right tar paper can reduce damage from wind-driven rain, ice dams, and minor punctures during installation. Today’s choices also include synthetic underlayments that imitate tar paper’s role while offering improved tear resistance and longevity.
Key Types Of Roofing Underlayment Tar Paper
Understanding the major categories helps homeowners pick a product that fits climate, roof pitch, and project timeline. The two broad families are traditional felt (tar paper) and modern synthetic underlayments. Within traditional felt, there are common weight classes that indicate thickness and durability. Synthetic options deliver higher resistance to tearing and quicker installation in many cases, though they may come at a higher upfront cost.
Traditional Felt (Asphalt-Saturated) Tar Paper
- 15-pound felt: Lightweight and economical, suitable for low-slope roofs or temporary protection in mild climates. More prone to tearing under fasteners and extended exposure.
- 30-pound felt: The most common residential choice, offering a balance of cost, durability, and ease of handling. Performs well in average climates and standard roof pitches.
- 60-pound felt: Heavyweight option providing enhanced puncture resistance and longer exposure tolerance, typically used in extreme weather regions or steep pitches.
Synthetic Underlayments
- Fiberglass or polymer-based synthetic: Higher tear strength, faster installation, and better resistance to water and UV exposure. Often lighter and more resilient than traditional felt.
- Self-adhering (ice and water shield) options: Sticky backings provide secure adhesion at eaves and valleys, reducing wind uplift and streamlining installation on roofs with potential ice dam risk.
- High-traction surfaces: Textured or coated surfaces improve footing for roofers and reduce slippage on steep pitches.
Climate and Roof Design Considerations
Choosing the best tar paper depends on local climate, roof slope, and typical weather patterns. Regions with heavy rainfall, snow, or high winds demand underlayments with superior water resistance and faster installation timelines. Steep roofs benefit from underlayment with robust tear resistance to withstand wind-driven debris. In colder climates, ice dam prevention features, such as a self-sealing or self-adhering layer at eaves, can be critical to preventing water intrusion after snowfall.
Performance Factors To Compare
When evaluating tar paper options, homeowners should weigh several performance metrics. Key factors include water resistance, tear strength, UV exposure tolerance, ease of installation, compatibility with chosen shingles, and warranty terms. Remember that underlayment is a temporary protection layer; improper installation or selecting a product with insufficient durability can compromise the entire roofing system over time.
Water Resistance And Exposure Tolerance
Traditional felt is rated for limited exposure time before shingle installation, then covered. Synthetic underlayments often tolerate longer exposure, enabling flexible construction schedules and reducing weather-related delays.
Tear Strength And Puncture Resistance
Roofing projects encounter fasteners, nails, and debris. Higher tear resistance reduces the risk of exposing the deck and may reduce call-backs for repairs due to nail pops or punctures.
Adhesion And Wind Uplift
Self-adhering options provide superior wind uplift resistance, especially on second-story or high-wind roofs. Adhesion quality matters for long-term performance and easier handling during installation.
Compatibility With Shingles
Some shingles pair better with certain underlayments. Asphalt shingles generally work well with traditional felt or synthetic underlayments, while asphalt-free options offer broader compatibility with metal or tile roofing systems.
Installation Tips For The Best Results
Proper installation maximizes underlayment performance. Start by inspecting the roof deck for damage, then ensure clean, dry surfaces before laying tar paper. Install per local codes, typically starting from eave to ridge. Nail or staple at recommended intervals, avoiding over- or under-fastening. For self-adhering products, remove release film and press firmly to ensure full adhesion. At roof penetrations, flashings and sealants should be integrated carefully to prevent leaks. Maintain a clean work area and store underlayment in a dry place to prevent deterioration before installation.
Maintenance And Longevity Considerations
Even with the best tar paper, roof longevity depends on proper installation, ventilation, and subsequent maintenance. Periodic inspections after severe storms can catch punctures or wear early. If a roof deck shows signs of moisture, address the issue promptly to prevent mold and structural damage. When re-roofing, evaluate whether upgrading to a synthetic or self-adhering underlayment provides a longer service life relative to cost and installation time.
Cost And Availability
Tar paper costs vary with material and thickness. Traditional 15- and 30-pound felt remain cost-effective, while 60-pound felt and synthetic underlayments command higher prices but may offset labor and repair costs over time due to durability. Availability depends on region, supplier, and project scale. Homeowners should factor in the local climate and expected exposure duration before selecting a product.
Choosing The Best Tar Paper For Your Roof
For most residential roofing projects in moderate climates, a 30-pound felt offers a solid balance of protection, cost, and ease of use. In harsher climates, or on roofs with heavy exposure, upgrading to a higher weight felt or a synthetic underlayment improves tear resistance and longevity. For eaves and valleys prone to ice dam issues, consider a self-adhering ice-and-water shield to reinforce critical areas. Always verify that the chosen underlayment is compatible with the type of shingles and local building codes.
Frequently Asked Questions
- What is tar paper used for in roofing?
- Is synthetic underlayment better than traditional tar paper?
- How long does tar paper last under normal conditions?
- Can tar paper be installed over existing shingles?