How to Shingle a Roof Safely and Efficiently

While different shingle types require slightly varying installation methods, estimating roofing materials is relatively straightforward. Measure each roof section in square feet and add all the areas together to obtain the total square feet. The result represents how much shingle and underlayment material your project requires. Shingles are available in packages that cover approximately 33.3 square feet. Your supplier will likely ask for the number of squares your roof covers. A square is simply the total square feet divided by 100.

You'll also need linear-feet measurements for the ridge shingles that cover the roof's apex, starter shingles for the first row of material, and the drip edge that encircles the roof's perimeter. If necessary, add step and chimney flashing needs and flashing or boots for roof penetrations like intersecting walls, plumbing penetrations, or air vents.

Organizing your roofing project in detail will save time and frustration later in the process.

• Make a plan to locate the dumpster near the site but not directly under the roof. 

• Roofing materials are heavy and can be awkward to handle. Plan on having at least one other person on site and working with you to help carry and install materials. The extra person can also hold ladders and assist with tool organization.

• Ensure you have enough air compressor hose to reach all roof areas.

• Move patio furniture and other items from around the home. 

• Place several tarps below the work area to catch demolition debris and waste materials.

• Clear a convenient outdoor location to place new materials.

Use your measurements and plan to order the materials and supplies listed above. Add about 10% to 20% extra roofing materials to your order. Explain the precise drop-off locations to the dumpster provider and materials delivery supplier.

Most municipalities require you or your roofing company to obtain a building permit for roof replacements. Additionally, many locations require a special permit to place a dumpster in the street if that's your only option. Apply for and obtain the necessary permits for your project well before starting work.

Part of knowing how to install shingles is becoming familiar with the building codes related to roofing. Depending on the building code in your location, you may be able to leave one layer of shingles under a new one. However, in most cases, removing the existing shingles is best when replacing your roof.

• Use a shingle stripper shovel tool to remove the majority of existing shingles and underlayment, starting at the ridge and prying them off as you work toward the eaves. Take extra care not to step on loose materials. Use a claw hammer to remove any nails left behind.

• Remove the drip edge flashing around the perimeter, as it will experience damage in the shingle removal process. Also, remove any flashing that suffers damage during the step. In many cases, it's advisable to simply replace all the roof flashing every time you replace your roof shingles.

Install the drip edge flashing by cutting it to the appropriate length with tin snips and securing it with manually-driven roofing nails through its top flange and into the roof deck. Allow a ½-inch space between the lower drip edge flange and the existing fascia.

Install other roof flashings as appropriate for your roof, including penetration boots, chimney and skylight flashing, kick-outs, and valley protection flashing. Install step flashing as necessary, depending on your roof's specific needs.

Roof deck protection needs vary by climate, location, and the building code in your area. Roof deck protection is available in self-adhesive rolls that protect against ice and water intrusion near the eaves, synthetic underlayments, and roofing felt. Install the necessary underlayments using a tacker hammer stapler according to the manufacturer's instructions starting at the bottom and working your way up the roof.

Install the shingle starter strips at the roof's lowest edge using coil nails and an appropriate nail gun. Extend the edge of the strips 1/2 inch past the drip edges. Continue along all the eaves to meet the building code and up each rake if you wish to provide additional weather protection.

Snap a chalk line representing the top edge of the first row of shingles across the roof. Consult the manufacturer's nailing pattern requirements and your local building code for the correct number of nails per shingle in your location. Lay the first shingle in place on the chalk line and use your roofing nailer to secure it to the roof deck.

• Install the next and subsequent shingles directly next to the first one before installing them all the way across the roof.

• Snap another chalk line representing the top edge of the next row of shingles. 

• Install the second and remaining courses, staggering the shingle edges by six inches from one row to the next. 

• Continue to the roof's ridge. Overlap the roof apex with the top of the last row of shingles. Cut away material to accommodate the ridge vent if your home has that feature.

Center and bend ridge shingles over the top of each roof ridge. Nail them in place approximately one inch from the edge, depending on the shingle manufacturer's requirements, until you reach the end of the ridge. Cover any exposed roofing nails in the cap shingles with spots of roofing cement.