Cedar Shake Roofing: Proper Sheathing and Underlayment

What You'll Need
Cedar shakes
Nail gun or nails and a roofing hammer
Drip edge
Ice and water barrier material
15-pound felt
2 inch galvanized roofing nails
Circular saw

Cedar shake roofing gives an attractive, natural appearance to any home, and it lasts longer than a shingled roof. Cedar shakes last up to 50 years before they need replacing or repair. Cedar shakes are not the same as cedar shingles; they are thicker and have a rougher texture that increases their durability. Cedar shakes are most often made of Western red cedar, and they are more expensive than asphalt shingles. They are also more difficult to lay and are not resistant to fire. In some areas, the cedar shake roof may be prohibited, so check with your local building code enforcement office before you begin installation. All of the materials needed for this project can be purchased at your local home improvement store. 

Step 1 – Preparations

Open the packages of cedar shakes and mix them up to evenly distribute the various colors and sizes. This prevents unattractive patches of the same color on your roof. Now, install the underlayment by nailing a drip edge along the eaves, and then an ice and water barrier material should be installed on the lower part of the roof that overlaps the drip edge.

Step 2 – Nail Down the Felt

Place a strip of 15-pound felt over the area above the barrier material, allowing the bottom edge of the felt to overlap the material. Nail drip edges along the rakes after placing the felt. Use a nail gun or roofing hammer and nails to nail the top edges of the felt into the sheathing about once every 5 to 6 feet.

Step 3 – Cedar Shake Installation

Install the cedar shakes in a single, straight course at a 9-inch exposure, making sure the thicker end of the shakes extend 1/2 inch beyond the drip edge. Let the first shake hang over the drip edge, and then nail it in place. Place another shake at the opposite edge of the roof and nail it down. Tie a string to the thick end of each shake, and align the ends of the remaining shakes with the string as you lay them. Space the cedar shakes 3/8 -inch apart. Lay a second course of cedar shakes directly over the first layer, making sure the ends of each are even. Make sure to overlap the shakes. No joint should be exposed. Then, cover each nail as you continue along the roof. Complete the rest of the roof in the same way.

Step 4 – Apply a Second Layer of Felt

Cut an 18 inch strip of 15-pound felt and place it over the top portion of the shake. Position the bottom edge of the felt 17 inches up from the thick end of the shake and continue up the length of the roof. Lay felt over the top of each course of shakes in the same way. Check your progress from the ground every few courses to make sure you haven't created an undesirable pattern.

Step 5 – Finishing Touches

Cut away any shakes that overlap the ridge of the cedar shake roof with a circular saw, making sure they are even with the ridge. Cut them wherever necessary to make them fit around vents and flashing, and in valleys. Use a circular saw for straight lines and a saber saw for curved lines. Caulk over nails and any exposed holes.