Roofing underlayment is the protective layer installed between your roof decking and your shingles. It serves as a secondary water barrier and helps protect your home if wind-driven rain, ice, or damaged shingles allow water to get beneath the roofing material. (https://portlandroofingco.com/recent-work/)
Not all underlayments are the same. Each type offers different levels of protection, durability, and cost.
15-Pound Felt Underlayment
Advantages
- Most economical option
- Long history of use in residential roofing
- Provides basic water resistance
Disadvantages
- Tears more easily during installation
- Absorbs moisture
- Can wrinkle when wet
- Shorter lifespan than synthetic products
Best For
- Budget-conscious roofing projects
- Simple roof designs
- Detached garages, sheds, and outbuildings
- Situations where building codes allow its use
30-Pound Felt Underlayment
Advantages
- Thicker and more durable than 15-pound felt
- Better resistance to tearing
- Improved moisture protection
- More stable during installation
Disadvantages
- Heavier to install
- Still absorbs moisture
- Not as durable as synthetic underlayments
Best For
- Homes needing a traditional felt system
- Steeper roofs
- Areas with moderate weather exposure
Standard Synthetic Underlayment
Synthetic underlayment has become the industry standard for many residential roofing projects. https://portlandroofingco.com/contact/
Advantages
- Much stronger than felt
- Lightweight and easier to install
- Highly resistant to tearing
- Water resistant
- Lies flatter on the roof deck
- Better performance during rainy installation periods
Disadvantages
- Higher cost than felt
- Protection level varies by manufacturer
Best For
- Most residential roof replacements
- New construction
- Homes in the Pacific Northwest
- Homeowners seeking better protection without a major upgrade
Upgraded Deck Defense Underlayment
Deck Defense is a premium synthetic underlayment designed to provide enhanced protection and durability compared to standard synthetic products.
Advantages
- Superior tear resistance
- Excellent traction for installers
- Better moisture protection
- More durable during extended exposure
- Helps provide a stronger roofing system
Disadvantages
- Higher initial investment
Best For
- Homes with complex roof designs
- Higher-end roofing systems
- Long-term homeowners
- Areas with heavy rain and wind exposure
Ice & Water Shield
Ice & Water Shield is a self-adhering waterproof membrane that seals around nails and provides the highest level of leak protection available beneath shingles.
Advantages
- 100% waterproof
- Self-sealing around roofing nails
- Superior leak protection
- Protects vulnerable roof areas
- Excellent defense against wind-driven rain and ice dams
Disadvantages
- Highest cost
- More difficult to remove during future roof replacements
Best For
- Roof valleys
- Eaves and overhangs
- Around chimneys and skylights
- Low-slope roof sections
- Areas prone to ice dams
- Homes in wet climates like Oregon and Washington
Which Underlayment Should Your Roof Have?
Basic Protection
15-pound or 30-pound felt
- Rental properties
- Outbuildings
- Budget-focused projects
Good Protection (Most Homes)
Standard synthetic underlayment
- Most residential roofs
- Typical Portland-area homes
- Excellent balance of cost and performance
Better Protection
Upgraded Deck Defense
- Long-term homeowners
- Higher-value homes
- Roofs exposed to heavy weather
Best Protection
Full synthetic or Deck Defense system with Ice & Water Shield in critical areas
- Valleys
- Roof penetrations
- Eaves
- Low-slope sections
This is the system many professional roofing contractors recommend because it provides excellent overall protection while targeting the most leak-prone areas with the highest level of waterproofing.
Portland Roofing Company’s Recommendation
Each home is as unique as it’s owner and there is not one standard way we would recommend for everyone. We provide free estimates so reach out and we can get all of the necessary information to let you know what we would recommend just for you! (https://app.acuityscheduling.com/schedule/5e3b2ef3)
Remember: Shingles are your roof’s first line of defense. Underlayment is your home’s backup protection when severe weather, aging shingles, or unexpected damage occur. Investing in quality underlayment can help prevent costly repairs and provide added peace of mind for years to come.
