Asphalt-Saturated Felt Roof Underlayment

Tamko No. 30 UL ASTM Asphalt Saturated Organic Felt Roof Underlayment 36 in x 72 ft, 216 sq ft

Coverage area216 sq.ft.
Underlayment typeAsphalt-Saturated Felt
Unrolled length72 ft
Application methodNail/Staple

Pickup on Fri, Apr 10 from Miami, FL

Overview
Articles

Asphalt Saturated Felt Roof Underlayment

When it comes to protecting your roof investment, what happens beneath your shingles matters just as much as what sits on top. Asphalt saturated felt serves as your roof's critical second line of defense, providing essential protection against moisture infiltration and extending the life of your entire roofing system.

What Is Asphalt Saturated Felt Underlayment?

Asphalt saturated organic felt is a time-tested roofing underlayment that's been protecting homes for over a century. This traditional material consists of organic paper or fiberglass mats that are thoroughly saturated with asphalt-based compounds, creating a water-resistant barrier between your roof deck and primary roofing materials.

Felt Type	Weight (per 100 sq ft)	ASTM Classification	Typical Applications
15-pound Felt	11.5-12.5 lbs (ASTM) / 7.6-8.8 lbs (Non-ASTM)	Type I (D226)	Light residential, temporary protection
30-pound Felt	26.4-27.3 lbs (ASTM) / 15.7-19.9 lbs (Non-ASTM)	Type II (D226)	Standard residential, commercial applications

Understanding ASTM Standards for Quality Assurance

Not all felt underlayment performs equally. The key to reliable protection lies in choosing products that meet established industry standards. ASTM D226 specifications cover asphalt-saturated organic felt used in roofing and waterproofing.

Standard	Type	Minimum Weight	Key Requirements
ASTM D226	Type I (#15)	11.5 lbs/100 sq ft	Higher tear resistance, water absorption limits
ASTM D226	Type II (#30)	26.4 lbs/100 sq ft	Superior durability, enhanced protection
ASTM D4869	Type I (#15)	8.0 lbs/100 sq ft	Basic performance requirements

Benefits and Advantages of Asphalt Saturated Felt

✅ Key Advantages

Cost-Effective: ~$5.00/square vs. $7-10/square for synthetic
Proven Track Record: 100 years of reliable performance
Effective Moisture Barrier: Excellent seepage protection
Breathability: Allows vapor transmission while blocking water
Fire Rating Support: Helps achieve Class A/C ratings

⚠️ Considerations

UV Sensitivity: Requires immediate shingle coverage
Weight: Heavier than synthetic alternatives
Temperature Sensitivity: Can crack in cold, leach in heat
Tear Susceptibility: More prone to installation damage

Cost-Effective Protection

The primary advantage of asphalt-saturated felt remains its affordability. Felt underlayment costs around $5.00 per square (100 square feet), while synthetic alternatives range from $7.00-$10.00 per square. For budget-conscious homeowners, this price difference can translate to significant savings on large roofing projects.

Proven Track Record

ASTM D226 30# asphalt saturated organic roofing felt has been a trusted roofing underlayment for over 100 years. This extensive history provides confidence in the material's ability to protect residential and commercial structures across diverse climate conditions.

Effective Moisture Barrier

When used under asphalt shingles, felt serves as a secondary water-resistant membrane against wind-driven rain, providing protection when individual shingles are damaged or dislodged. The material's asphalt saturation creates excellent seepage barrier properties, particularly effective when applied in thicker 30-pound configurations.

Installation Best Practices and Professional Tips

Installation Phase	Requirements	Best Practices
Pre-Installation	Clean, dry roof deck	Store rolls upright, check weather conditions
Low-Slope Roofs (2:12-4:12)	19-inch overlap minimum	Double layer coverage across entire roof
Steep Roofs (>4:12)	2-inch overlap minimum	Ensure consistent water shedding
Valley Installation	Vertical section first	Start bottom, overlap 2 inches, seal cuts
Post-Installation	Immediate shingle coverage	Protect from UV and weather exposure

Pre-Installation Requirements

Successful felt installation begins with proper preparation. The roof deck must be clear of all debris and moisture prior to installing the felt, and rolls should be stored upright in a dry location, never installed when wet or over a wet roof deck.

Overlap and Fastening Techniques

Proper overlap ensures continuous protection. With low-slope roofs (2:12 up to 4:12), roofers overlap felt courses by at least 19 inches, doubling the layer of underlayment across the entire roof, while steeper roofs require upper courses to overlap lower ones by 2 inches.

Comparing Felt vs. Synthetic Underlayment Options

Feature	Asphalt Saturated Felt	Synthetic Underlayment
Cost per Square	~$5.00	$7.00-$10.00
Coverage Efficiency	14 rolls for 2,700 sq ft home	3 rolls for 2,700 sq ft home
UV Resistance	Poor - immediate coverage required	Excellent - 6-12 months exposure
Tear Resistance	Moderate - prone to damage	High - withstands foot traffic
Water Absorption	Can absorb and wrinkle	Water-resistant, wrinkle-free
Installation Safety	Slippery surface	Non-slip surface with guides
Weight	Heavy - challenging to handle	Lightweight - easier installation

🏠 Case Study: Residential Installation Success

A homeowner in the Midwest chose 30-pound ASTM D226 asphalt saturated organic felt for their 2,400 square foot ranch home renovation. The project required 24 rolls of felt, installed by certified contractors following manufacturer guidelines.

Project Detail	Specification	Result
Home Size	2,400 sq ft ranch	✅ Complete coverage achieved
Felt Used	24 rolls ASTM D226 30#	✅ No material waste
Performance Period	3 years post-installation	✅ Zero moisture infiltration
Weather Events	Multiple severe storms	✅ No damage or leaks
Cost Savings	vs. Synthetic underlayment	💰 $800 saved
Installation Time	Professional crew, 1 day	⏱️ Completed on schedule

The cost savings compared to synthetic alternatives allowed budget allocation toward premium architectural shingles, creating an optimal balance of protection and aesthetics.

— Midwest Homeowner, 2021-2024 Performance Review

Choosing the Right Felt for Your Project

Project Type	Recommended Felt	Key Considerations
Budget-Conscious Residential	ASTM D4869 #15	Immediate shingle installation required
Standard Residential	ASTM D226 #30	Better tear resistance and durability
Severe Weather Zones	ASTM D226 #30 or Synthetic	Enhanced protection against wind-driven rain
Solar Panel Installations	ASTM D226 #30	Coordinate with solar contractors
Metal Roofing	Consider Synthetic	Better heat resistance properties

Frequently Asked Questions

How long can asphalt saturated felt be exposed before shingle installation?

#15 felt should not remain exposed longer than a month, while #30 felt can extend up to two months, though immediate coverage is always recommended.

Can I install felt underlayment myself?

While possible for experienced DIYers, professional installation ensures proper techniques, code compliance, and warranty protection. Improper installation can void manufacturer warranties and compromise roof performance.

What's the difference between perforated and non-perforated felt?

ASTM D226 covers asphalt-saturated organic felts with or without perforations. Perforated versions allow additional breathability but may sacrifice some water resistance. Choose based on specific climate requirements and manufacturer recommendations.

Does felt work with solar panel installations?

Yes, quality asphalt saturated felt underlayment provides excellent protection for roofs with solar panel systems. Ensure proper coordination between roofing and solar contractors for optimal installation sequencing.

How do I identify quality felt products?

Look for ASTM compliance markings, check actual weight specifications rather than just nominal ratings, and purchase from reputable suppliers who provide product documentation and technical support.

Ready to Choose the Right Underlayment?

Get professional advice on selecting the best asphalt saturated felt for your roofing project. Our experts can help you balance cost, performance, and durability requirements.

View Our Felt Products