Fastening cedar siding correctly is crucial for its longevity, stability, and aesthetic appeal, preventing issues like cupping, splitting, and nail stains. Proper nailing techniques ensure the wood can expand and contract naturally with changes in moisture and temperature.
Key Principles for Fastening Cedar Siding
The method of fastening depends largely on the siding's width and orientation. Careful attention to nail type, placement, and spacing is essential for a successful and durable installation.
1. Choosing the Right Fasteners
Selecting appropriate nails is paramount to prevent staining and ensure a secure, lasting installation.
- Material: Always opt for stainless steel or hot-dipped galvanized nails. These materials resist corrosion, which is vital to prevent unsightly black stains (iron oxide) from leaching into the cedar, especially in wet conditions. Aluminum nails are also a suitable option.
- Type: Use ring-shank or spiral-shank nails for superior holding power in wood.
- Head: Small-diameter heads, such as those found on casing or siding nails, are preferred as they can be easily concealed or set flush with the surface.
- Length: Nails should be long enough to penetrate the framing or furring strips by at least 1 to 1.5 inches to ensure adequate holding strength.
2. Nailing Techniques by Siding Width
The width of your cedar siding dictates the optimal nailing pattern to accommodate natural wood movement without damage.
For Narrow Siding (Up to 6 inches wide)
- For siding patterns up to 6 inches wide, use a single nail per stud.
- Place this nail approximately one inch up from the lap (the overlap point) of the siding piece. This allows the lower, unnailed edge to move freely, significantly reducing the risk of cupping or splitting.
For Wide Siding (8 inches and wider)
- For siding patterns 8 inches wide and wider, you should face nail each piece.
- Use two nails per piece at each framing member.
- Position these nails 2 ½ to 3 inches apart horizontally. This specific spacing is critical to allow for the dimensional movement (expansion and contraction) of wider boards without causing the wood to split.
3. Fastening Vertical Cedar Siding
When cedar siding is installed vertically, the fastening method adapts to the orientation:
- Vertical siding should be securely nailed to horizontal blocking or furring strips. These horizontal supports provide the necessary attachment points for the vertical boards, ensuring stability and proper air circulation behind the siding.
4. General Installation Best Practices
Beyond specific nailing patterns, consider these additional tips for a successful cedar siding installation:
- Pre-drilling: For thin boards, when nailing close to ends or edges, or in very cold weather, pre-drilling pilot holes can effectively prevent the wood from splitting.
- Nail Depth: Ensure nails are driven flush with the siding surface. Avoid over-driving nails, which can crush the wood fibers and diminish their holding power, or under-driving, which leaves nail heads exposed.
- Moisture Content: Install cedar siding with an appropriate moisture content, typically between 10% and 12%, to minimize significant movement after installation.
Summary of Nailing Guidelines
| Siding Width | Nailing Method | Nail Placement |
|---|---|---|
| Up to 6 inches | Single Nail (per stud) | Approximately 1 inch up from the lap |
| 8 inches and wider | Face Nail (Two Nails per stud) | 2 ½ to 3 inches apart |
| Vertical Applications | N/A | To horizontal blocking or furring strips |
For more detailed guidance on cedar siding installation, including preparation and finishing, consult comprehensive resources such as those provided by industry associations. For example, the Western Red Cedar Lumber Association offers valuable insights and guides.
