Roofing felt, or underlayment, is a vital layer that protects your roof structure from moisture, wind, and other environmental elements. At GreenGo Roofing, we know that delays in roofing projects happen—whether due to weather, scheduling, or material supply issues. In such cases, homeowners and contractors often wonder how long roofing felt can be left exposed without compromising the integrity of the roofing system. Here, we break down the details on exposure limits, factors that impact roofing felt durability, and what you can do to protect it when timelines are unpredictable.
Understanding Roofing Felt and Why It’s Important
Roofing felt is designed to shield the roof deck from moisture, acting as a secondary barrier before shingles or tiles are installed. GreenGo Roofing emphasizes that while felt is essential for roof integrity, it’s not designed for prolonged exposure to the elements. If roofing felt is exposed too long without the final roofing layer, it can degrade, absorb moisture, and lose its effectiveness—ultimately impacting the life of your roof.
Types of Roofing Felt We Use at GreenGo Roofing
We work with two main types of roofing felt, each with different durability and exposure limits:
Asphalt-Saturated Felt
Asphalt-saturated felt, or “tar paper,” is a traditional choice that provides water resistance and basic protection. However, in our experience, it’s more susceptible to UV degradation and moisture absorption, meaning it’s best to cover it within a short time after installation.
Synthetic Roofing Felt
Synthetic felt, made from durable polymers, offers greater UV, wind, and water resistance. For Arizona’s intense sun and unpredictable weather, GreenGo Roofing often recommends synthetic felt, which can withstand longer exposure periods if project delays are likely.
How Long Roofing Felt Can Be Left Exposed
The duration roofing felt can be left exposed depends largely on the type used and environmental factors. Here’s what we’ve seen work well for each type:
Asphalt-Saturated Felt: Exposure Limits
Under typical Arizona conditions, we recommend covering asphalt-saturated felt within 7 to 10 days. Sun, rain, and wind in the area can quickly break down the material if left exposed too long. Asphalt felt may tolerate slightly longer in mild climates, but here in Arizona, prompt covering is crucial.
Synthetic Felt: Extended Exposure Limits
Synthetic felt can generally be left exposed for up to 90 days or more, depending on the brand and quality. Some high-quality synthetic underlayment’s we use at GreenGo Roofing can withstand exposure for up to 180 days, which is invaluable when timelines are unpredictable.
Factors That Affect Roofing Felt Durability
Several environmental and situational factors influence how long roofing felt can remain exposed without compromising its quality:
Weather Conditions
UV exposure, rain, and wind are the primary concerns. Arizona’s high UV exposure can quickly degrade standard asphalt felt, while rain and monsoon winds put strain on any exposed underlayment. At GreenGo Roofing, we monitor weather patterns closely and always recommend covering felt if rain is forecasted.
Installation Quality
A well-installed underlayment lasts longer. Our team ensures that every felt layer is properly secured, overlapping edges and sealing seams, to protect against wind, moisture, and UV damage.
Roof Slope and Position
The slope and orientation of your roof can also impact felt exposure time. Roofs with a steeper pitch shed water faster, reducing the risk of moisture pooling on the felt. South-facing roofs in Arizona may also have shorter exposure tolerances due to prolonged sun exposure.
Potential Risks of Prolonged Roofing Felt Exposure
Leaving roofing felt exposed longer than recommended can result in several issues. Here’s what we at GreenGo Roofing monitor for and suggest you look out for as well:
UV Degradation
Sunlight exposure weakens asphalt-based materials, causing them to become brittle and prone to tearing. Once this happens, the felt’s waterproofing capability is significantly reduced, and it’s more vulnerable to damage during shingle installation.
Moisture Absorption and Mold Growth
Roofing felt is water-resistant, not waterproof. In Arizona’s monsoon season, rainfall can saturate exposed felt, leading to mold and reducing the felt’s effectiveness as a barrier.
Physical Damage from Wind or Debris
Strong winds can lift improperly fastened felt, tearing it or creating gaps. Additionally, Arizona’s dust storms can create small abrasions on the felt, weakening it over time.
GreenGo Roofing’s Tips
If your roofing project faces delays, here are GreenGo Roofing’s top recommendations to protect exposed felt:
Temporary Covering Solutions
For projects facing delays, tarps, breathable covers, or plastic sheeting are effective at shielding roofing felt from UV rays and rain. We recommend securing these covers to avoid wind-related issues. This approach is particularly helpful if rain or storms are expected.
Proper Installation Practices
Our GreenGo Roofing team ensures that roofing felt is installed with secure fastenings and overlapping seams to minimize water and wind intrusion. Installing felt properly from the start can extend its durability if it needs to be exposed temporarily.
Signs Your Roofing Felt Needs Replacement
If roofing felt has been exposed beyond its ideal timeframe, it’s essential to inspect it. GreenGo Roofing advises checking for:
- Brittleness or Cracking: This is a clear sign of UV damage, especially in asphalt felt.
- Water Marks or Wrinkling: Moisture exposure can cause the felt to warp or wrinkle, compromising its function.
- Visible Tears or Loosened Edges: Wind and foot traffic can cause visible damage, indicating that replacement may be necessary.
Our Recommendations for Managing Delays
When roofing projects experience delays, we take extra steps to protect your investment:
Weather Monitoring and Scheduling Flexibility
We keep a close eye on Arizona’s weather conditions and schedule work to minimize exposure risks. For example, we aim to avoid felt installation before forecasted storms and arrange temporary protection if delays are anticipated.
Quality Material Choices for Long-Lasting Protection
Choosing the right underlayment matters. At GreenGo Roofing, we recommend synthetic felt for projects where exposure is likely to be prolonged, ensuring your roof has the best protection possible during any waiting period.
Clear Communication and Client Education
Homeowners may not realize the importance of underlayment exposure limits. We make it a priority to communicate these limits clearly and offer alternatives or protective measures if delays arise.
Getting Started with GreenGo Roofing
Leaving roofing felt exposed for extended periods requires careful planning, especially in regions with extreme weather conditions like Arizona. Asphalt-saturated felt should generally be covered within a week to prevent UV and moisture damage, while synthetic felt offers more flexibility, allowing up to several months of exposure when needed. By choosing high-quality materials, following proper installation practices, and taking protective steps during delays, GreenGo Roofing ensures that your underlayment remains effective until your roof is fully completed. Our goal is to protect your investment and ensure the long-term performance of your roofing system.
