How to Shingle a Valley Roof

Roof lines create dramatic effects and add to the overall style and feel of a home. When it comes time to put shingles on a valley roof, special care and attention is needed to keep the valley free from leaks. Remember, more water travels through the valley on a roof than any other part of the roof.

Difficulty: Moderate

Instructions

Things You'll Need:

• Shingles
• Hammer or nail gun
• Metal snips
• Carpenter's apron
• Shingles
• Roofing cement
• Copper or aluminum flashing
• Nails
• Chalk Line
• #90 mineral surface roofing
• Tin snaps
• Ladder
• Rope for safety

1. Mark the valley with a chalk line. The lines should go 9 inches and 18 inches on either side of the valley. Lines are parallel with the valley.

2. Lay an 18-inch-wide piece of flashing down the middle of the valley, using the lines as a guide. Mark the end of the flashing according to the angle at the edge of the roof.

3. Cut the flashing to match the angle of the roof line.

4. Nail the flashing down to the roof by placing nails along the outer edge of the flashing.

5. Spread roofing cement along the outer edges of the flashing to seal the flashing and cover the nails.

6. Lay a 36-inch-wide piece of waterproof roofing material centered along the valley. Mark the end of the material along the roof edge as you did with the flashing material.

7. Cut the end of the roofing material to match the roof edge and then nail down the material in the valley. Nails go on the outer edges.

8. Lay a shingle (don't nail it) along one side of the valley so at least 1/3 of the shingle crosses to the other side of the valley.

9. Mark the top two corners of the shingle and measure the marks from the valley. Create a chalk line parallel to the valley with the measurements from the first shingle.

10. Place another set of chalk lines 3 inches from either side of the valley. Do not place any nails inside the 3-inch line toward the valley.

11. Nail the first shingle into place with the shingle pressed into the valley.

12. Install a second shingle on the opposite side of the roof to create an "x" with the first shingle at the roof edge.

13. Install shingles up the valley in a straight line with the first shingle using the chalk line as a guide. You won't criss-cross any more shingles.

14. Lay a fresh set of chalk lines on top of the shingles 3 inches on either side of the valley.

15. Add the shingles to the roof from the side away from the valley. When you reach the chalk line at the valley, cut the last shingle to fit in place. The shingles should not cross the chalk line at the valley.

Tips & Warnings

• Wear soft-soled shoes to avoid damaging the roof.
• The valleys should have a mineral-surfaced, roll roofing material covering the area as part of the leak prevention system.
• Make sure you secure a rope around your waist to provide protection against falling.
• Valleys will leak if you don't properly apply the flashing and other leak prevention materials.