Asphalt paper, commonly known as roofing felt or tar paper, is a staple underlayment used in many shingle roofing projects. Home Depot offers several grades and brands of asphalt-saturated paper and synthetic underlayments, making it a go-to source for homeowners and contractors. This guide explains what asphalt paper is, the options available at Home Depot, how to choose the right product, installation tips, and practical buying advice to ensure a durable roof deck and effective moisture protection.
What Asphalt Paper Is And How It Works
Asphalt paper is a paper-based underlayment saturated with asphalt or asphalt-like resins. It acts as a secondary moisture barrier and helps seal the roof deck from wind-driven rain during installation. Traditional tar paper typically comes in weights such as 15-pound or 30-pound, indicating its tear resistance and thickness. Some products labeled as “self-adhesive” include a pressure-sensitive adhesive layer for easier attachment and a quicker seal at overlaps. Home Depot stocks both traditional felt and newer synthetic underlayments, giving installers options for different climates and shingle types.
Popular Types And Specifications Available At Home Depot
Understanding options helps ensure the right product for a given roof and climate. The following are common categories you’ll find at Home Depot:
- Felt Paper (Tar Paper) – Traditional asphalt-saturated paper, often 15# or 30#, used as a secondary moisture barrier under asphalt shingles. Less expensive but less resistant to tearing in windy conditions.
- Roofing Underlayment (Synthetic) – A polymer-based underlayment that provides higher tear resistance, better water resistance, and lighter weight than felt.
- Self-Adhering Underlayment – Features a pressure-sensitive adhesive layer and a release film for quick, durable installation; particularly advantageous in windy or cold installations.
- Underlayment Thickness – Weight-based or mil-based specifications. Heavier products often offer greater puncture resistance and longevity in demanding climates.
- Water-Resistance Features – Many synthetic underlayments advertise higher permeance resistance and UV resistance, extending protection during temporary weather exposure.
When shopping at Home Depot, look for brands commonly carried in the U.S. market, such as GAF, Owens Corning, CertainTeed, and other reputable roofing suppliers. Each product page will list application guidelines, climate suitability, and installation instructions.
How To Choose The Right Asphalt Paper For A Home Project
Selecting the correct underlayment depends on roof slope, climate, and local building codes. Consider these decision factors:
- Climate And Weather – In wet or windy regions, heavier felt or synthetic underlayment with strong tear resistance and moisture barrier properties is advisable.
- Shingle Type – Conventional asphalt shingles typically pair with standard felt or mid-range underlayments, while hail-prone areas might benefit from advanced synthetic underlayments with superior puncture resistance.
- Roof Slope – Low-slope roofs may require more durable underlayments and careful installation to prevent water infiltration during rain delays.
- Installation Time Frame – Self-adhering underlayments reduce wind risk during installation and may be preferred in areas with frequent gusts or limited labor.
- Code Compliance – Some municipalities specify minimum underlayment standards. Check local building codes and Home Depot product pages for compatibility.
Installation Tips For Asphalt Paper And Underlayment
Proper installation is crucial to maximize the effectiveness of asphalt paper. The following best practices help ensure a durable roof deck:
- Surface Preparation – Ensure the roof deck is dry, clean, and free of protrusions that could damage the underlayment.
- Overlap And Fastening – Overlap edges per product instructions (commonly 19 to 24 inches for felt; synthetic underlayments may have different overlap requirements). Align wraps to prevent air pockets and secure with corrosion-resistant roofing nails in recommended spacing.
- Ventilation And Drying Time – Allow adequate drying time after installation if weather conditions require. Self-adhering products can simplify fastening but need clean contact surfaces.
- Temperature Considerations – Cold temperatures can hinder adhesion for self-adhesive products. Warm weather improves seal formation and overall performance.
- Edge And Ridge Details – Use appropriate transitions and sealants at eaves, rakes, valleys, and ridges to prevent water intrusion.
Pros And Cons Of Asphalt Paper Versus Synthetic Underlayment
Choosing between traditional felt and synthetic underlayment often comes down to cost, climate, and performance expectations. Key considerations:
- – Traditional felt generally costs less upfront but may require more labor due to tearing and replacement concerns in windy conditions.
- Durability – Synthetic underlayments offer higher tear resistance, better puncture protection, and longer service life in challenging environments.
- Water Protection – Synthetic products typically provide superior water shedding and UV resistance, reducing exposure time during construction.
- Ease Of Installation – Self-adhering underlayments can streamline installation but may come with higher material costs and temperature sensitivity.
Buying Guide: What To Look For At Home Depot
Home Depot stocks a range of underlayments and roofing papers. When shopping, review product specifications carefully and consider the following:
- Weight And Ply – 15# or 30# felt, or synthetic equivalents, indicating tear resistance and thickness.
- Self-Adhesive Option – For faster sealing at overlaps and edges, particularly in windy locations.
- Warranty And Manufacturer Claims – Check warranty terms and whether the product is recommended for your shingle type and climate.
- Availability – Some items may be seasonally stocked; online ordering with in-store pickup offers flexibility for scheduling.
- Compatibility – Ensure the product is compatible with local building codes and the intended roofing system.
Maintenance, Damage Prevention, And Replacement Considerations
Underlayment is not a long-term roofing surface; it protects during installation and early life of the roof. Consider these maintenance notes:
- Damage Checks – Inspect after heavy wind, hail, or heavy rain. Replace damaged sections promptly to avoid leaks.
- Moisture Exposure – Prolonged moisture exposure can degrade traditional felt; synthetic options tolerate moisture better during construction.
- Ventilation – Proper attic ventilation helps extend roof system life and prevent moisture buildup that can affect underlayment performance.
Frequently Asked Questions
What is asphalt paper used for in roofing?
Asphalt paper serves as a secondary moisture barrier, protecting the roof deck before shingles are installed and helping seal the roofing system against wind-driven rain.
Can Home Depot cut or customize underlayment?
Most Home Depot locations offer standard packaging. Some stores may provide cutting services or guidance, but oversized orders are typically handled via online purchasing with in-store pickup.
Is self-adhering underlayment worth it?
For projects in windy regions or colder seasons, self-adhering underlayment can save labor time and provide a tighter seal, though it may have higher upfront costs and temperature sensitivity during installation.