How to Install Roof Shingles: A Complete Step-by-Step Guide
Asphalt shingle roof installation is the process of fastening overlapping shingle courses to a prepared roof deck over underlayment and flashing, working from the eave to the ridge. The work follows 6 stages: safety setup, roof preparation, underlayment and flashing, layout, shingle coursing, and final inspection. Asphalt shingles protect residential, multi-family, and commercial buildings, and they last 20 to 30 years (InterNACHI).
The main parts of the system are the roof deck, drip edge, ice and water shield, underlayment, flashing, starter strip, field shingles, ridge caps, and roof deck ventilation. This guide covers each stage, manufacturer instructions, common mistakes, and the point where a roofing contractor in Morris County, NJ, is the safer choice.
Why Choose Asphalt Shingles?
Asphalt shingles are the most common roof covering in the United States, used in more than 80 percent of home roofing and re-roofing projects (Home Innovation Research Labs, 2018). Five benefits explain that share:
Lower material cost: New asphalt shingle roofs cost $3.44 to $12 per square foot ($37 to $129 per m²) installed, and a 2,000 sq ft (186 m²) home runs $6,885 to $23,993 (This Old House, March 2026).
Service life of 20 to 30 years: Three-tab shingles last about 20 years, and architectural shingles last about 30 years (InterNACHI).
Simple installation: Roofers cut shingles with a hook-blade knife and fasten them with roofing nails.
Wide product range: Three-tab, architectural, and impact-resistant lines fit rental properties and custom homes. Hidalgo Brothers compares the two main types in its guide to architectural vs. 3-tab shingles.
Brand choice: GAF, Owens Corning, CertainTeed, Atlas Roofing, IKO, TAMKO, and Malarkey all sell asphalt shingle lines.
Asphalt shingle roofing suits pitched roofs. Flat and low-slope roofs need a different system, covered on the flat roofing page.
Tools and Materials You'll Need
Asphalt shingle installation needs 8 tool groups and 10 material groups. Gather them before the first shingle goes down.
Tools
Roofing nail gun or hammer
Flat pry bar and shingle shovel
Hook-blade utility knife
Tin snips and chalk line
Tape measure and framing square
Circular saw for decking cuts
Ladder with stabilizer, roof brackets, and tie-off anchors
Magnetic sweeper
Materials
Asphalt shingles (3-tab or architectural)
Starter strip shingles
Synthetic underlayment or felt
Ice and water shield
Drip edge (aluminum or steel)
Step flashing, valley flashing, and pipe boots
Hip and ridge cap shingles
Roofing nails (galvanized steel, stainless steel, or aluminum)
Roofing cement
Ridge vents and intake vents
Nails need a shank of 12 gauge or thicker and a head 3/8 in (9.5 mm) wide, according to Owens Corning's Duration installation instructions. Those instructions recommend nails that meet ASTM F1667, the standard specification for driven fasteners.
1. Taking the Necessary Safety Precautions
Falls are the main roofing hazard, so 4 safety steps come before any roof work. Complete all four before climbing.
1.1. Clean the Work Area
Clear tools, toys, and debris from the ground below the work zone. Cover landscaping beside the house with tarps. Set ladders on firm, level ground. Mark a drop zone, so family members and pets stay clear.
1.2. Check the Weather Forecast
Schedule the job for a dry stretch with low wind. GAF installs leak barriers only when the deck is dry and the air is between 45°F and 120°F (7°C to 49°C), and it advises hand-sealing shingles in fall and winter (GAF). Owens Corning tells installers to use extra care when handling shingles below 40°F (4°C).
1.3. Wear the Right Clothes
Wear soft rubber-soled shoes, work gloves, safety glasses, and hearing protection for nail gun work. Add a hard hat and fall-arrest gear tied to a roof anchor on any steep roof or high eave.
1.4. Use Ladders Appropriately
Extend the ladder at least 3 ft (0.9 m) above the roof edge, and set its base about one-quarter of the ladder's working length away from the wall (a 4:1 ratio). The Occupational Safety and Health Administration (OSHA) sets both rules in 29 CFR 1926.1053. The same rule requires the climber to face the ladder, and OSHA guidance calls for three points of contact at all times.
2. Preparing the Roof
Roof preparation takes 5 tasks, and the shingles do not go down until all 5 are done.
2.1. Calculate Your Roof's Square Footage
Measure the length and width of each roof plane and multiply. A roofing square covers 100 sq ft (9.3 m²). A 6:12 pitch adds about 12% to the footprint area, so a 2,000 sq ft (186 m²) footprint measures about 2,236 sq ft (208 m²) of roof. Add 10% for waste at hips, valleys, and cuts, and the order comes to about 25 squares. The bundle wrapper lists the coverage per bundle.
2.2. Remove Large Pieces of Debris
Remove satellite dishes, antenna mounts, and loose gutter hardware. Pull stray nails with the flat bar. Bag trash from the roof surface before tear-off starts.
2.3. Carefully Remove Old Roofing Materials (Tear Off)
Strip the old roofing to the deck, so hidden rot and moisture damage show before the new roof goes on. Work from the ridge down in sections and protect landscaping with tarps. Check the product instructions and local code before keeping any old layer. Hidalgo Brothers handles tear-off as part of roof replacement in Morris County.
2.4. Check and Fix the Roof Decking for Any Damage
Walk the deck and mark soft spots, delaminated panels, and rot. Replace damaged boards with the same thickness of decking. Fasten loose boards to the rafters with ring-shank nails. A solid deck holds nails and keeps shingles flat.
2.5. Ensure Proper Roof Deck Ventilation
The National Roofing Contractors Association (NRCA) recommends 1 sq ft (0.09 m²) of net-free ventilation area for every 150 sq ft (14 m²) of attic floor in heating and mixed climate zones (NRCA). Balance intake vents at the eaves with exhaust vents at the ridge. Ventilation removes moisture and heat that age the shingles from underneath.
3. Installing Roofing Underlayment and Flashing
Underlayment and flashing form the water-shedding layers under the shingles, and they go on in 5 steps.
3.1. Install Drip Edge Along the Eaves
The International Residential Code (IRC) requires underlayment over the drip edge along the eaves and under the drip edge along the rakes (IRC R905.2.8.5, quoted by Journal of Light Construction). Metal drip edge sends water past the fascia and protects the deck edge. What a drip edge does and why a roof needs one is covered in a separate Hidalgo Brothers guide.
3.2. Apply Ice and Water Shield
Cover the eaves with a self-adhering membrane in cold climates. The International Building Code (IBC) ice barrier provision runs from the lowest roof edge to at least 24 in (600 mm) inside the exterior wall line, using a self-adhering polymer-modified bitumen sheet or two bonded layers of underlayment (Building Enclosure). Ice dam protection of this kind matters in Morris County winters. Check the adopted New Jersey code with the local building department.
3.3. Install Roofing Underlayment
Roll synthetic underlayment or felt over the rest of the deck from the eave upward. Owens Corning sets standard slopes at 4:12 and steeper, and slopes from 2:12 up to 4:12 need double-overlap underlayment or a self-adhered barrier with metal drip edge. Follow the lap lines printed on the underlayment, and fasten it per the product instructions. FEMA Technical Fact Sheet 7.3 states "Always use underlayment."
3.4. Install New Flashing
Install step flashing at sidewalls, valley flashing in valleys, and pipe boots at plumbing vents. Lap each piece over the shingle course below it. Replace old flashing instead of reusing it. Signs your roof flashing needs repair lists the failure patterns to check.
3.5. Covering the Joints and Valleys
Line open valleys with ice and water shield and metal valley flashing. Cut shingle edges along a straight chalk line and seal them with roofing cement. Seal flashing joints with the sealant the flashing maker specifies.
4. Mapping Out Your Shingle Layout
Layout controls straight courses and a clean ridge line.
4.1. Snap Chalk Lines for Straight Shingle Courses
Snap a vertical line at the center of the roof and horizontal lines up the slope at the exposure listed on the shingle wrapper. Check the distance to the ridge, and adjust the exposure slightly across several courses, so the last course meets the ridge evenly.
5. Installing Your Roof Shingles
Shingle installation runs bottom-up from the eave to the ridge in 5 steps.
5.1. Install the Starter Strip
Place purpose-made starter shingles along the eave with the sealant strip facing up. Owens Corning specifies 5 fasteners per starter shingle, placed 2 to 3 in (50 to 75 mm) up from the eave edge. With drip edge, the starter overhangs the eave and rake by 1/4 to 3/4 in (6 to 19 mm). The starter strip seals the bottom edge of the first course against wind-driven rain.
5.2. Lay the First Course of Shingles
Align the first course with the starter and the chalk line. Drive each nail flush with the shingle surface, in the nailing zone printed on the shingle. Overdriven nails cut the mat, and high nails let tabs lift.
5.3. Continue Coursing up the Roof
Offset each course so no vertical joint lines up with the joint below. Work in a stair-step pattern across the roof to keep courses straight. Nails must penetrate at least 3/4 in (19 mm) into the deck or pass through it by 1/4 in (6 mm), according to Owens Corning. FEMA Technical Fact Sheet 7.3 calls for roofing nails instead of staples and for six nails per shingle at eaves in high-wind regions, which FEMA defines as design wind speeds above 90 mph (145 km/h).
5.4. Flash All Penetrations and Valleys
Flash all penetrations and valleys before the next course covers them. Slide step flashing under each sidewall course, set pipe boots over vent pipes, and seal the boot base.
5.5. Install Ridge Cap Shingles
Bend each cap shingle over the ridge and fasten one nail on each side. FEMA notes that hips and ridges need longer nails, since the shingles are thicker there. Install ridge vents first on ventilated ridges, and keep nails out of the vent channel.
6. Product-Specific Installation Instructions
Each shingle line publishes its own installation instructions, and the printed instructions in the bundle govern the nailing pattern, exposure, and warranty terms. Atlas Roofing, GAF, Owens Corning, CertainTeed, IKO, TAMKO, and Malarkey each print instructions for their lines. Five differences show up across the instructions:
Nail count: Owens Corning requires 6 fasteners per shingle plus 4 spots of roofing cement per shingle on steep slope and mansard applications above 21:12 (60 degrees).
Nail placement: Each line prints a nailing zone on the shingle, and nails outside the zone void the pattern.
Hand-sealing: GAF calls for a quarter-sized dab of roofing cement under each shingle in cold weather, on slopes steeper than 21:12, and on mansard roofs.
Starter course: Each maker names its own starter product, and Owens Corning requires an Owens Corning starter.
Hip and ridge: Makers sell matching hip and ridge caps, such as Atlas Pro-Cut and Atlas StormMaster hip and ridge shingles.
Re-roofing over asphalt shingles falls under the same rule: the product instructions and local code decide whether an old layer can stay.
Installing Clay Tiles, Metal Panels, and Wood Shakes
Clay tile, metal panels, and wood shakes each follow a different installation method from asphalt shingles.
Clay tiles: Clay weighs far more than asphalt shingles, so a structural review of the deck and framing comes first.
Metal panels: Standing-seam panels use concealed clips, and through-fastened panels use gasketed screws. Hidalgo Brothers lists metal as a 40 to 70 year option on its roof installation page.
Wood shakes and shingles: Wood needs gaps for expansion and treatment for fire resistance in wildfire zones.
7. Final Inspection and Cleanup
A final inspection covers 6 checks.
Walk the roof and check course alignment, nail placement, and sealant bond.
Verify that ridge caps, flashing, and pipe boots are sealed and lapped correctly.
Sweep the roof and gutters with a magnetic sweeper to collect stray nails.
Inspect the ground, driveway, and landscaping for debris.
Photograph the finished roof from four angles for your records.
Confirm that ridge vents and soffit vents are open.
Schedule a roof inspection after the first major storm to catch early problems.
8. Common Mistakes to Avoid During Asphalt Shingle Installation
There are 8 common mistakes in asphalt shingle installation.
Overdriven nails: They cut the shingle mat.
High nailing: Nails above the nailing zone let tabs lift in wind.
Skipped starter strip: The first course edge stays exposed to wind-driven rain.
Stacked joints: Aligned joints create leak paths and a wavy roof line.
Short underlayment laps: Water reaches the deck.
Reused flashing: Corroded flashing fails early.
Missing hand-seal in cold weather: Tabs stay loose when the sealant strip does not activate.
Blocked ridge vents: Caps nailed through the vent channel stop airflow.
9. When to Call a Professional
Hire a roofing contractor when any of these 6 conditions apply.
The roof is steep, or the eave sits high above the ground.
The deck needs structural repair or new framing.
The home sits in a high-wind or wildfire zone with strict code requirements.
The project includes skylights, solar panels, dormers, or complex valleys.
You lack fall-protection equipment and roofing experience.
The manufacturer or your municipality requires a licensed installer or a permit.
Hidalgo Brothers LLC installs and replaces roofs for homeowners in Morris County, NJ. The roof installation page lists the process, and the service areas page lists the towns served. For project planning, read how much a full roof replacement costs in New Jersey and how to choose a trustworthy roofing contractor in NJ. Call (973) 525-6835 or request a free estimate. The office is at 350 W Dewey Ave, Wharton, NJ 07885, open Monday to Friday 8am to 6pm and Saturday 9am to 3pm.
10. Ensuring Success: Best Practices and Compliance
Code compliance and manufacturer instructions govern a correct asphalt shingle roof installation.
10.1. Region-Specific Considerations
Cold climates: Ice dam protection at eaves and valleys, plus hand-sealing in fall and winter.
Coastal climates: FEMA calls for stainless steel nails within 3,000 ft (900 m) of saltwater.
High-wind zones: Six nails per shingle at eaves and hand-sealed rakes.
Wildfire zones: Class A fire-rated assemblies.
10.2. Training and Resources
FEMA and the Insurance Institute for Business and Home Safety (IBHS) publish free guidance for roofers:
FEMA Technical Fact Sheet No. 7.3, Asphalt Shingle Roofing for High-Wind Regions
FEMA Technical Fact Sheet No. 7.2, Roof Underlayment for Asphalt Shingle Roofs
FORTIFIED Home, a program of IBHS
International Residential Code, Chapter 9, Roof Assemblies
10.3. Compliance
New Jersey municipalities adopt the building code and set permit rules, so confirm permit and inspection requirements before tear-off.
11. Final Thoughts
Asphalt shingle roof installation rewards preparation over speed. Safety setup, deck repair, roof deck ventilation, underlayment, flashing, and layout decide how the roof performs. Follow the printed instructions for the shingle line, add ice dam protection at the eaves, and nail inside the printed nailing zone. A licensed roofing contractor handles the full asphalt shingle roof installation process for homeowners who prefer to stay off the roof. Regular roof inspections and maintenance help a new roof reach its 20 to 30 year range, and how long an asphalt shingle roof lasts in NJ explains the local factors.
12. FAQ: How to Install an Asphalt Shingle Roof
How much does asphalt shingle roof installation cost?
Asphalt shingle roof installation costs $3.44 to $12 per square foot ($37 to $129 per m²), or $6,885 to $23,993 for a 2,000 sq ft (186 m²) home (This Old House, March 2026). Architectural shingles cost more than 3-tab, and tear-off, deck repair, and steep slopes add to the total.
How long does an asphalt shingle roof last?
An asphalt shingle roof lasts 20 to 30 years: about 20 years for 3-tab shingles and about 30 years for architectural shingles (InterNACHI). Hot climates shorten shingle life.
Can I install asphalt shingles over existing shingles?
Maybe, depending on the product instructions and local code. Tear-off to the deck exposes hidden rot and moisture damage, so many roofers strip the old roof first.
How many nails per shingle do I need?
The count depends on the product and the slope. Owens Corning requires 6 fasteners per shingle above 21:12, and FEMA calls for six nails per shingle at eaves in high-wind regions. Use roofing nails, never staples.
Can I install asphalt shingles in cold weather?
Yes, with extra care and hand-sealing. Owens Corning calls for extra care below 40°F (4°C), and GAF advises hand-sealing with a quarter-sized dab of roofing cement under each shingle in fall and winter. GAF recommends storing shingles above 70°F (21°C) the day before installation.
How long does installation take?
Most Hidalgo Brothers installations take one to three days, and metal and low-slope work take longer (Hidalgo Brothers roof installation).
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