For rolled roofing applications, the best nails are typically galvanized roofing nails featuring an annular ring shank and a large head. These specific features are crucial for ensuring superior holding power, resistance against wind uplift, and preventing the material from tearing over time.
Essential Characteristics of Rolled Roofing Nails
When securing rolled roofing, the nails must meet specific criteria to ensure long-lasting performance and prevent common issues like uplift and leaks.
- Corrosion Resistance: This is paramount for any outdoor roofing application to prevent rust, which can compromise the nail's integrity and stain the roofing material.
- Galvanization: Nails should be galvanized, meaning they are coated with zinc to prevent rust. There are two primary methods:
- Hot-Dipped Galvanized: Offers superior, long-lasting corrosion resistance, making them ideal for harsh or humid climates.
- Electro-Galvanized: Provides good protection for less severe conditions and is often more cost-effective.
- While the galvanized coil nail is a very common and economical choice for general roofing, particularly for shingle applications where its smooth shank is suitable for nail guns, rolled roofing requires enhanced features beyond just galvanization to provide optimal security.
- Galvanization: Nails should be galvanized, meaning they are coated with zinc to prevent rust. There are two primary methods:
- Shank Type for Superior Grip:
- Annular Ring Shank: This is the preferred choice for rolled roofing. The series of rings on the shank provides significantly better pull-out resistance compared to smooth shanks. This mechanical locking action is crucial for preventing the rolled material from lifting or tearing, especially in windy conditions or areas prone to temperature fluctuations.
- Unlike the smooth shank found on many common shingle nails (such as the galvanized coil nail), the ring shank mechanically locks into the wood, offering a far more secure hold for the continuous rolled material.
- Head Size for Tear Prevention:
- Large Flat Head: Nails specifically designed for rolled roofing typically have a larger head (e.g., 3/8" or 7/16" diameter). This wider surface area distributes the pressure more evenly across the rolled material, minimizing the risk of the nail head pulling through or tearing the roofing over time due to thermal expansion and contraction or foot traffic.
- Appropriate Length:
- 1-inch: Generally suitable for a single layer of rolled roofing over standard decking.
- 1 1/4-inch to 1 1/2-inch: Recommended for multiple layers, thicker rolled roofing materials, or when fastening to thicker sheathing.
Recommended Nail Types for Rolled Roofing
- Galvanized Ring Shank Roofing Nails: These combine the necessary corrosion protection with the superior holding power of a ring shank and the wide head to secure the material effectively. They are the standard and most reliable choice for most rolled roofing installations.
- Plastic or Metal Cap Nails (Optional for Enhanced Security): For maximum tear-out resistance and hold-down, especially on low-slope roofs or in high-wind areas, cap nails can be used. These have an integrated plastic or metal cap that further spreads the load, providing an even larger bearing surface and preventing blow-offs.
Nail Features Comparison
Feature | Smooth Shank Nail (Common for Shingles) | Annular Ring Shank Nail (Ideal for Rolled Roofing) |
---|---|---|
Holding Power | Good for individual shingles | Excellent, highly resists pull-out |
Shank Texture | Smooth, relies on friction | Series of rings for mechanical lock |
Primary Use | Asphalt shingles, general fastening | Rolled roofing, decking, subflooring |
Cost | Generally less expensive | Slightly more expensive due to specialized design |
Pull-Through | Higher risk with continuous or softer roofing materials | Significantly lower risk |
Best Practices for Installing Rolled Roofing Nails
Correct installation is as important as choosing the right nail to ensure the longevity and performance of your rolled roofing system.
- Nail Spacing: Always follow the manufacturer's recommendations for nail spacing, which is typically every 2-3 inches along the edges and every 6-12 inches in the field of the material.
- Proper Penetration: Nails should fully penetrate the roofing material and firmly seat into the decking, ideally by at least 3/4 inch into the wood substrate.
- Avoid Over- or Under-Driving:
- Over-driven nails can cut through the roofing material, compromising its integrity and creating potential leak points.
- Under-driven nails will not hold the material securely, leading to flapping, detachment, and potential wind damage.
- Nailing Pattern: Begin nailing from the lower edge of the roof and work upwards, ensuring proper overlap of layers and nailing through both layers where specified by the roofing material manufacturer. For more information on roofing practices, consult resources like the National Roofing Contractors Association (NRCA) https://www.nrca.net/.
Selecting the right nails—specifically galvanized, large-headed, annular ring shank nails—is critical for the longevity and performance of your rolled roofing system, providing the necessary resistance to wind, water, and material movement.