Roofing Felt 15 vs 30: Which is Better for Your Project?: Fast-Track Guide to Choosing the Right Roofing Felt for Your Needs

Choosing the right roofing felt is a crucial step in ensuring the longevity and effectiveness of your roofing system. When comparing Roofing Felt 15 vs 30, homeowners and professionals alike often want to know: which is the better option for your specific project? The numbers "15" and "30" refer to the weight of the roofing felt per square (a roofing square covers 100 square feet), commonly designated as #15 (15-pound) and #30 (30-pound). Here’s a breakdown to help you make an informed decision.

Roofing Felt 15:

15-pound roofing felt is lighter and thinner, making it easier to handle and install. It offers basic water resistance and is typically used as underlayment for lighter roofing materials or where budget is a primary concern. It's a popular choice for sheds, garages, or lower-cost projects where the roof won’t experience as much wear and tear.

Roofing Felt 30:

30-pound roofing felt is almost twice as thick, providing enhanced durability and protection against water. It’s more resistant to tearing and is better suited for areas exposed to harsher climates or for roofing materials that remain exposed for longer during installation. Contractors often recommend #30 felt for residential homes or steeply pitched roofs where additional strength is beneficial.

Which Is Better for Your Project?

Your choice depends on the structure, climate, budget, and roofing material:

1. Weather Resistance: #30 felt offers superior moisture and wind resistance, ideal for regions with heavy rain, snow, or wind.
2. Project Type: Use #15 for smaller, lower-cost projects, and #30 for residential homes or commercial buildings requiring greater protection.
3. Installation Difficulty: #30 felt’s thickness can make it slightly harder to work with, but comes with added benefits.
4. Cost: #15 is generally cheaper, but #30’s added durability may save money in repairs long-term.

As a designer, selecting the right materials is about balancing aesthetics, functionality, and longevity. Just as thoughtful planning is integral to a well-designed space, choosing the appropriate underlayment is essential for a roof’s structural integrity. Before making a final decision, consider investing in digital project management or roof planning tools that help visualize the structure, detect potential design or water drainage issues, and optimize material use. Integrating visual planning with material selection streamlines the overall design process and leads to a more resilient, well-performing roof.

Tips 1:

Always check your local building codes before purchasing roofing felt. Some municipalities or insurance policies may specify the minimum weight or type required for certain roof pitches or structures.

FAQ

Q: What is the main difference between Roofing Felt 15 and 30?

A: The primary difference is thickness and durability. #30 felt is heavier, thicker, and more resistant to moisture and tears than #15 felt.

Q: Can Roofing Felt 15 be used for homes?

A: Yes, but it's typically recommended for lighter-duty applications. For added protection, especially in areas with severe weather, #30 felt is preferred.

Q: Is Roofing Felt 30 more expensive to install?

A: Material costs are higher for #30 felt, and it may take slightly longer to install due to weight, but the increased lifespan and durability can offset the upfront costs.

Q: Does roofing felt type affect shingle lifespan?

A: Using a higher-quality felt like #30 can provide better protection for your shingles and underlying roof deck, potentially prolonging their lifespan.

Q: Should both felts be used together?

A: Generally, you choose one or the other based on your requirements; double layering is not common except in specific high-risk zones or where required by code.