When choosing roofing felt, one common question is whether to use 15W or 30W. Both options have their advantages, but the best choice depends on your specific roofing project. This guide will help you understand the differences between 15W and 30W roofing felt and when to use each.
1. What is Roofing Felt?
Roofing felt, also called underlayment, is a protective layer installed between the roof deck and the shingles or other roofing materials. It provides a waterproof barrier, reduces roof wear, and adds an extra layer of durability to your roofing system. Felt underlayment typically comes in rolls and is available in 15 lb (15W) and 30 lb (30W) varieties.
2. Key Differences Between 15W and 30W Roofing Felt
| Feature | 15W Roofing Felt | 30W Roofing Felt |
|---|---|---|
| Thickness | Thinner | Thicker |
| Strength | Moderate strength | Stronger and more durable |
| Tear Resistance | More likely to tear | Less likely to tear |
| Weight | Lightweight | Heavier |
| Cost | Lower cost | Higher cost |
| Application | Best for lighter-duty roofs | Ideal for more demanding roofs |
3. Advantages of 15W Roofing Felt
- Lightweight: Easier to handle and install, making it suitable for DIY projects.
- Cost-Effective: More affordable, making it a good option for budget-conscious homeowners.
- Good for Simple Roofs: Works well for roofs with gentle slopes or where heavy-duty protection isn’t critical.
4. Advantages of 30W Roofing Felt
- Durability: The thicker material is stronger and more resistant to tearing during installation or in high winds.
- Better Waterproofing: Provides enhanced protection against water infiltration.
- Long-Lasting: More suitable for roofs that are exposed to severe weather conditions or heavy foot traffic during installation.
- Professional Use: Preferred by roofing professionals for its reliability and strength.
5. When to Use 15W Roofing Felt
15W roofing felt is best for:
- Lightweight Roofing Projects: Such as small sheds, detached garages, or low-slope roofs.
- Short-Term Roofing: Temporary or low-cost solutions where the roof isn’t expected to face extreme weather conditions.
- Budget-Friendly Options: Projects where cost is a primary concern.
6. When to Use 30W Roofing Felt
30W roofing felt is recommended for:
- Harsh Weather Conditions: Areas prone to heavy rain, snow, or strong winds.
- High-Traffic Roofs: Roofs where contractors or maintenance crews will frequently walk during or after installation.
- Long-Term Roofing: Durable and reliable for high-quality, long-lasting roofs.
- Steeper Slopes: Offers better grip and tear resistance, ideal for steep or complex roof designs.
7. Synthetic Underlayment vs. Felt
It’s worth noting that synthetic underlayment is becoming a popular alternative to traditional felt. While felt is time-tested, synthetic materials offer even greater durability, tear resistance, and lightweight properties, albeit at a higher cost.
Conclusion
The choice between 15W and 30W roofing felt depends on your specific roofing needs. If you’re working on a lightweight, budget-friendly project, 15W felt may suffice. However, for better durability, waterproofing, and resistance to tears, 30W felt is the superior option. Always consider factors such as climate, roof type, and your budget when making your decision. For more demanding roofing projects, investing in 30W felt is often the wiser choice, ensuring long-term protection and reliability.
