Best Way to Shingle a Valley

Best Way to Shingle a Valley

Shingling a valley is a crucial part of roof installation. It ensures proper water runoff and protects against leaks. The technique and materials you use matter significantly. Here’s a detailed look at the best ways to shingle a valley.

Understanding Roofing Valleys

Roofing valleys are the lines where two roof planes intersect. They carry a higher volume of water. Good shingling keeps water away from the roof deck. There are primarily two methods: open valleys and closed valleys.

Open Valley

Open valleys use metal flashing. Shingles end a few inches short of the valley center. This metal is visible and directs water down the valley.

• Install metal flashing first.
• Make sure to center it in the valley.
• Nail the flashing every 12 inches.
• Ensure no nails are within 6 inches of the valley center.

Closed Valley

Closed valleys cover the valley entirely with shingles. There are two main methods here: woven valleys and closed-cut valleys.

Woven Valley

• Lay shingles from one slope, then overlap with the opposite slope.
• Intertwine the shingles in the valley.
• Creates a continuous, interwoven pattern.

Closed-Cut Valley

• Install shingles on one roof plane first.
• Extend them across the valley.
• Apply shingles on the adjacent plane and cut them along the valley centerline.
• The lower shingle layer is hence covered by the upper ones.

Step-by-Step Shingling Process

Here’s a step-by-step guide for each method.

Open Valley Technique

1. Start with an underlayment. Install waterproof underlayment along the valley.
2. Place the metal flashing. Center it in the valley and secure with roofing nails.
3. Lay shingles. Place shingles as you would normally do, stopping at least 6 inches from the valley center.
4. Clip the corners of the shingles facing the valley to prevent water from being directed under shingles.

Closed-Cut Valley Technique

1. Begin with an underlayment. Cover the valley entirely, just like in the open valley method.
2. Install shingles on one side. Let them extend across the valley onto the adjacent roof plane.
3. Place shingles on the other roof plane. Ensure they reach and cover the valley’s center.
4. Trim the top shingles. Cut them exactly along the valley centerline. This creates a neat, finished look.
5. Seal the seam with roofing cement to prevent water infiltration.

Woven Valley Technique

1. Lay an underlayment across the valley.
2. Shingle the first roof plane. Let the shingles overlap into the valley.
3. Shingle the second roof plane. Interweave shingle layers across the valley, creating a seamless look.
4. Press firmly to ensure no gaps form where water could seep through.

Key Considerations

Keep a few things in mind for effective valley shingling.

• Materials: The quality of your shingles and flashing matters. Invest in high-grade materials.
• Weather: Work on dry days. Wet conditions make shingles slippery and adhesives ineffective.
• Tools: Keep essential tools on hand: roofing nails, hammer, utility knife, roofing cement, and chalk line.
• Safety: Use proper safety gear. Working on a roof comes with inherent risks.

Common Mistakes to Avoid

Avoid these common errors for a durable roofing valley.

• Incorrect Nail Placement: Nails too close to the valley center compromise the flashing or shingles. Maintain at least six inches distance.
• Insufficient Overlapping: Ensure shingles overlap adequately to prevent water penetration.
• Poor Sealing: Unsealed seams or flashing edges can lead to leaks. Use roofing cement where necessary.
• Ignoring Manufacturer Instructions: Follow shingle and flashing manufacturers’ guidelines. Deviation could void warranties.

Maintenance Tips

Proper maintenance extends the lifespan of your roofing valley.

• Inspect valleys regularly, especially after harsh weather.
• Clear debris promptly. Leaves and twigs can trap moisture.
• Check for damage and repair immediately.
• Trim overhanging branches to reduce debris.

These steps ensure your valley remains functional and leak-free for years. Applying the correct technique with attention to detail makes all the difference.