Roofing Installation: Complete Guide

Overview

Typical Duration: 1-2 weeks
DIY Difficulty: ⭐⭐⭐⭐☆ (4/5)
Typical Cost: $8,000-$20,000 (2,000 sq ft house, 30 squares)
When to Hire: Most owner-builders hire this out
Required Inspection: Generally no separate inspection (part of framing)

Roofing is the most important weather protection for your entire investment. A quality roof installation protects everything you've built and everything you'll build. Rushing this phase or cutting corners leads to expensive water damage.

The biggest challenge is working at heights safely. Falls from roofs are the leading cause of construction injuries. If you're not comfortable with heights or don't have proper safety equipment, hire this out.

When This Phase Happens

Roofing should happen immediately after roof framing is complete.

Must be complete first:

Roof framing complete
Roof sheathing installed and nailed properly
Chimney chases framed
Any skylight openings framed
Roof vents positioned

Can happen in parallel:

Window and door ordering
Rough-in trade scheduling
Siding material selection

What comes after:

Window and door installation
Siding installation
Rough-in trades begin

Should You DIY This Phase?

DIY If:

Comfortable working at heights with safety equipment
Have 2-3 helpers available
Roof pitch under 6:12 (walkable without special equipment)
Simple roof design (no valleys, dormers, or complex angles)
Weather forecast is stable for 3-5 days
Have or can rent proper safety equipment

Hire Out If:

Afraid of heights or no safety equipment
Roof pitch over 8:12 (too steep to work safely)
Complex roof with multiple valleys and dormers
Want speed (pros do in 2-3 days vs 1-2 weeks DIY)
Can't get weather-stable period
Want warranty protection

My recommendation: Hire this out unless you have roofing experience and proper safety equipment. Professional crews work fast (protecting your house quickly), have proper insurance, and warranty their work.

I've seen owner-builders spend 2 weeks installing a roof that pros would do in 2 days, all while risking serious injury. The $4,000-$6,000 labor cost buys you safety, speed, and expertise.

Roofing Material Options

1. Asphalt Shingles (Most Common - 80% of homes)

Cost: $90-$120 per square installed ($2,700-$3,600 for 30 squares) Lifespan: 20-30 years Pros: Affordable, widely available, easy DIY, many colors Cons: Shorter lifespan than alternatives, less wind resistant Best for: Budget-conscious builds, standard residential

2. Architectural Shingles

Cost: $120-$160 per square installed ($3,600-$4,800 for 30 squares) Lifespan: 25-40 years Pros: Better appearance, longer warranty, more wind resistant Cons: More expensive, heavier (check framing capacity) Best for: Higher-end appearance, better warranty

3. Metal Roofing

Cost: $350-$600 per square installed ($10,500-$18,000 for 30 squares) Lifespan: 40-70 years Pros: Very long life, fire resistant, energy efficient Cons: Much more expensive, requires special installation skills Best for: Long-term ownership, rural/mountain settings

4. Tile or Slate

Cost: $600-$1,200+ per square installed ($18,000-$36,000+ for 30 squares) Lifespan: 50-100+ years Pros: Extremely durable, beautiful, fire resistant Cons: Very expensive, very heavy (requires engineered framing), complex installation Best for: High-end homes, specific architectural styles

This guide focuses on asphalt shingles (most common for owner-builders). Concepts apply to other materials with adjustments.

Materials Needed

Roofing Materials (30 squares = ~3,000 sq ft roof area)

Roofing Materials for 30 Squares (~3,000 sq ft roof area)
Item	Quantity	Typical Cost	Notes
Asphalt shingles	33 squares	$2,000-$3,300	Order 10% extra for waste
Synthetic underlayment	10 rolls	$500-$800	Better than felt paper
Ice and water shield	6 rolls	$300-$500	Eaves, valleys, penetrations
Drip edge (aluminum)	250 LF	$200-$350	Eaves and rakes
Ridge cap shingles	50 LF	$150-$250	Or cut from field shingles
Roofing nails (1-1/4")	30 lbs	$150-$225	Coil nails for nailer
Roof cement	6 tubes	$50-$90	Sealing and repairs
Valley flashing	80 LF	$200-$350	Metal or specialty shingles

Ventilation Components

Ventilation Components
Item	Quantity	Typical Cost	Notes
Ridge vent	40 LF	$120-$200	Continuous ridge preferred
Soffit vents	30 pieces	$150-$250	1:150 ventilation ratio
Roof vents (turtle vents)	4-6 vents	$80-$150	If not using ridge vent
Bathroom/kitchen exhaust caps	3-4 caps	$90-$150	Penetration flashings

Tools Required

Essential:

Roofing nailer (coil nailer) - rent $40-$60/day
Air compressor - rent $50-$80/day
Utility knife and plenty of blades
Chalk line
Tape measure (25 ft)
Tin snips for metal work
Flat pry bar
Hammer for hand nailing

Safety equipment (CRITICAL):

Roof harness and rope (OSHA required over 6 feet)
Roof brackets and staging - $150-$300/week rent
Toe boards for steep roofs
Non-slip shoes
Hard hat
Safety glasses

Nice to have:

Shingle cutter (cuts shingles cleanly)
Roofing hatchet
Magnetic sweeper (cleanup)
Nail apron

Specialized (rent):

Roof jacks and staging - $150-$300/week
Safety harness system - $80-$150/week
Ladder hoisting system - $100-$200/week
Dumpster or roof tear-off trailer - $400-$600/week

Step-by-Step Process

Days 1-2: Preparation and Underlayment

Roof preparation

Sweep roof deck clean of debris
Check for protruding nails (pound flush)
Verify sheathing is secure (add nails if needed)
Install drip edge at eaves (before underlayment)
Mark roof penetrations (vents, chimneys, skylights)

Ice and water shield installation

Install ice and water shield at all eaves (first 3-6 feet depending on climate)
Install at all valleys (36" wide centered on valley)
Install around all penetrations (chimneys, pipes, vents)
Install at sidewalls and anywhere water can enter
Overlap minimum 6 inches at seams

💡Pro Tip

Ice and water shield is expensive but critical. It's self-sealing around nails and creates waterproof barrier. Don't skip this - it prevents 90% of leak issues.

Underlayment installation

Start at eaves, working toward ridge
Roll out synthetic underlayment horizontally
Overlap 6 inches at horizontal seams
Overlap 6 inches at vertical seams (upper over lower)
Staple or nail per manufacturer specs
Keep taut but not stretched
Extend 3-6" past rake edges

Drip edge completion

Install drip edge at rakes (over underlayment)
Overlap sections 2 inches
Nail every 12 inches
Ensure proper overhang (1" beyond fascia)

Days 3-7: Shingle Installation

Layout and planning

Snap chalk lines for starter course alignment
Snap vertical lines every 4 feet for shingle alignment
Plan valley treatment (woven or cut)
Identify all penetrations and plan flashing

Starter course (critical for wind resistance)

Install starter shingles along eaves
- Use starter strip shingles OR
- Cut tabs off 3-tab shingles and reverse
Overhang drip edge 1/2" to 3/4"
Nail 3-4" up from edge (prevents nail exposure)
Seal down with roof cement if high wind area

First course installation

Install first full course over starter
Begin at rake edge (left or right, stay consistent)
Overhang rake edge 1/2" to 3/4"
Nail with 4 nails per shingle (6 in high wind areas)
- Place nails just below adhesive strip
- Don't overdrive (breaks seal)
- Don't under-drive (nail heads exposed)
Verify alignment with chalk lines

Subsequent courses

Offset each course per shingle pattern (typically 6" offset)
Maintain straight horizontal lines (check every 5 courses)
Maintain straight vertical seams (check every 4 feet)
Work across and up systematically
Don't work too far ahead in one area (can cause cupping)

⚠️Warning

Proper nailing is critical. Nails must hit sheathing (not just skip sheathing). Overdriven nails break the seal. Under-driven nails don't seal. Improper nailing is the #1 cause of shingle failure.

Nailing pattern for standard 3-tab shingle:

4 nails per shingle (6 in high wind zones)
1" from edges
Just below adhesive strip
Into solid sheathing
Straight in (not angled)

Days 5-7: Valleys, Penetrations, and Ridge

Valley installation (two methods):

Open valley (most waterproof):
- Install metal valley flashing
- Shingles cut and sealed to flashing
- 4-6" exposed valley center
- Seal all edges with roof cement
Woven valley (faster but less preferred):
- Shingles woven across valley
- No metal flashing
- Requires precise cutting and sealing
- Better for low-pitch roofs

💡Pro Tip

Use open metal valleys for best performance. Yes, they cost $200-$400 more, but valley leaks are the most common roof failure point.

Pipe boot installation:

Slide boot over pipe
Shingles below boot go under boot base
Shingles above boot go over boot base
Nail boot flange
Seal with roof cement
Never caulk around pipe (must allow movement)

Chimney flashing:

Install step flashing up sides (one piece per shingle course)
Install counter flashing into mortar joints
Seal with appropriate sealant (not roof cement on metal)
This is complex - consider hiring if you have chimney

Ridge cap installation:

Cut ridge cap shingles from field shingles OR use manufactured ridge cap
Begin at ends, work toward center
Overlap 5-6 inches
Nail each side of ridge (2 nails per cap shingle)
Last piece at center: cut to size and cement down

Ridge vent installation (if using):

Cut 1-2" slot along ridge (template provided with vent)
Install ridge vent over slot
Install ridge cap shingles over vent
Seal properly at ends

Final Day: Cleanup and Inspection

Quality checks:

Walk entire roof checking for:
- Exposed nail heads (seal with cement)
- Unsealed edges (apply cement)
- Proper alignment
- Secure flashings
- All penetrations properly sealed
Check from ground for straight lines

Cleanup:

Remove all debris from roof
Clean gutters if installed
Magnetic sweep of ground (picks up dropped nails)
Haul away packaging and waste

Code Requirements

Key IRC roofing requirements:

IRC R905.2.7 - Shingle fasteners: Minimum 4 fasteners per strip shingle, 6 in high wind areas (110+ mph)
IRC R905.2.8.5 - Ice barrier: Required where average daily temp in January is 25°F or less. Minimum 24" inside wall line.
IRC R905.2.7 - Underlayment: Required over entire roof deck. One layer minimum, two layers in high wind/freeze areas.
IRC R806 - Ventilation: Minimum 1:150 ratio (1 sq ft vent per 150 sq ft attic). Can reduce to 1:300 with proper balanced intake/exhaust.
IRC R905.2.4 - Slope: Asphalt shingles minimum 2:12 pitch (some require 4:12 minimum - check manufacturer)
IRC R905.2.8.2 - Valleys: Valleys require additional underlayment or ice shield

Subcontractor Considerations

If hiring roofing contractors (recommended):

What to look for:

Licensed and insured (verify workers comp)
Experience with residential roofing (5+ years)
Provides written warranty (workmanship and materials)
Can show recent similar projects
Uses quality materials (knows shingle brands and grades)
Includes all flashing and underlayment in quote
Proper safety equipment for crew

Typical pricing:

Tear-off and reshingle: $300-$450 per square ($9,000-$13,500 for 30 squares)
New construction (no tear-off): $250-$350 per square ($7,500-$10,500 for 30 squares)
Add for complex roof: +20-40% for multiple valleys, dormers, steep pitch
Shingle upgrade: +$30-$60 per square for architectural vs 3-tab

What's typically included:

All materials (shingles, underlayment, flashing, vents)
Labor for installation
Cleanup and disposal
Warranty (1-2 years workmanship, manufacturer warranty on shingles)

Timeline:

Lead time to book: 1-3 weeks (longer in spring/fall)
Duration once started: 2-4 days for typical residential roof
Weather delays: Plan for 2-3 weather days

Red flags:

No insurance certificate provided
Can't provide references
Pressure to use "leftover materials from another job"
Requires large deposit (10-25% is reasonable)
Will start "tomorrow" (good roofers are booked 2-4 weeks out)
Knocking on door after storm (many storm-chasers are scammers)

Common Mistakes

1. Working Without Safety Equipment

Why it's a problem: Falls from roofs cause serious injury or death. You can't build if you're in the hospital or dead. How to avoid: Use proper harness and rope system. Use roof jacks on steep roofs. Work in good conditions only. Cost if you don't: Injury, death, medical bills, project shutdown.

2. Roofing Over Wet Sheathing

Why it's a problem: Traps moisture, causes wood rot, mold growth, premature shingle failure. How to avoid: Only roof when sheathing is completely dry. Wait after rain. Check weather forecast. Cost if you don't: $8,000-$20,000 roof replacement, structural repairs.

3. Improper Nailing

Why it's a problem: Shingles blow off in wind, leak, fail prematurely. This is the #1 cause of roof failure. How to avoid: Use proper nail placement (just below adhesive strip). Nail into solid sheathing. Don't overdrive or under-drive. Cost if you don't: $5,000-$15,000 roof replacement, leak damage.

4. Skipping Ice and Water Shield

Why it's a problem: Leaks at eaves (ice dams), valleys, penetrations. Water damage to structure and interior. How to avoid: Install ice shield at all code-required areas plus any vulnerable spots. Yes, it's expensive - install it anyway. Cost if you don't: $2,000-$10,000 leak repairs, water damage remediation.

5. Poor Valley Installation

Why it's a problem: Valleys are the most likely leak point. Improper installation guarantees leaks. How to avoid: Use metal valley flashing. Install ice shield under valley. Cut shingles properly and seal well. Cost if you don't: $1,000-$3,000 per valley to repair, water damage.

6. Inadequate Ventilation

Why it's a problem: Shortens shingle life by 30-50%, causes ice dams, leads to mold in attic. How to avoid: Follow 1:150 ventilation ratio (or 1:300 with balanced system). Use ridge vent and soffit vents. Cost if you don't: Premature roof failure, $8,000-$15,000 early replacement.

7. Mixing Shingle Lots

Why it's a problem: Color variations create ugly striping pattern visible from ground. How to avoid: Order all shingles from same lot. If using multiple lots, blend bundles during installation. Cost if you don't: Ugly roof, potential full replacement for aesthetic fix.

8. Not Offsetting Shingles Properly

Why it's a problem: Creates "racing stripes" or alignment issues. Looks terrible, may leak. How to avoid: Follow manufacturer offset pattern (typically 6" for 3-tab, varies for architectural). Check alignment frequently. Cost if you don't: $5,000-$12,000 to tear off and reinstall correctly.

9. Improper Chimney Flashing

Why it's a problem: Chimney leaks are extremely common and cause extensive damage. How to avoid: Use proper step flashing and counter flashing. Seal with appropriate materials. Consider hiring a pro for this. Cost if you don't: $2,000-$8,000 chimney leak repairs, interior water damage.

10. Roofing in Extreme Temperatures

Why it's a problem: Shingles don't seal in cold (under 40°F), become brittle and crack. In extreme heat (over 90°F), shingles are too soft and damage easily. How to avoid: Roof when temps are 50-85°F. If must work in heat, work early morning. Don't roof in winter. Cost if you don't: Poor adhesion, cracked shingles, walking damage, premature failure.

Quality Checkpoints

Before moving to next phase, verify:

[ ] All shingles properly nailed (4-6 nails each)
[ ] Straight horizontal lines across roof
[ ] Proper shingle offset maintained
[ ] All valleys properly flashed and sealed
[ ] All penetrations (pipes, vents) properly flashed
[ ] Ridge vent or ridge cap properly installed
[ ] Drip edge installed at eaves and rakes
[ ] Ice and water shield at all required locations
[ ] Underlayment properly installed (no gaps or exposed deck)
[ ] No exposed nail heads (all sealed)
[ ] No shiners (nails missing sheathing)
[ ] Proper ventilation installed (meets 1:150 ratio)
[ ] All roof vents, caps installed
[ ] Chimney flashing complete and sealed
[ ] Cleanup complete (no nails on ground)
[ ] Gutters cleared of debris
[ ] View from ground shows straight, professional appearance

Budget Breakdown

Example for 30-square roof (2,000 sq ft house, ~3,000 sq ft roof):

Budget Breakdown for 30-Square Roof (2,000 sq ft house)
Item	Cost	Notes
Materials
Shingles (33 squares)	$2,000-$3,300	10% waste factor included
Underlayment	$500-$800	Synthetic preferred
Ice and water shield	$300-$500	Eaves, valleys, penetrations
Drip edge	$200-$350	Eaves and rakes
Valley flashing	$200-$350	Metal valleys
Ridge vent	$120-$200	Continuous ridge
Soffit vents	$150-$250	Intake ventilation
Pipe boots and caps	$150-$250	4-6 penetrations
Nails and cement	$200-$350	Bulk quantities
Labor (if hiring)
Installation labor	$4,500-$7,500	$150-$250 per square
Equipment (if DIY)
Roofing nailer rental	$200-$300	5 days
Compressor rental	$250-$400	5 days
Safety equipment rental	$150-$250	Harness, jacks, staging
Dumpster	$400-$600	Debris removal
Total (DIY)	$5,020-$7,650	Materials and equipment
Total (Hired)	$8,520-$13,650	Materials and labor

💡Pro Tip

Many owner-builders hire roofing out. The $3,500-$6,000 labor premium buys expertise, speed (2 days vs 2 weeks), safety, and warranty. This is often money well spent.

Timeline Tips

Best season: Late spring through early fall. Avoid extreme heat, cold, or wet seasons.

Weather considerations:

Must have 3-5 day dry forecast
Temperature 50-85°F ideal
No work in high winds (15+ mph is difficult, 25+ is dangerous)
Morning start in hot weather (shingles soft by afternoon)
Plan for 1-2 weather delays

Scheduling with other trades:

Complete roofing before scheduling interior trades
Windows and doors can install immediately after roof
Siding can begin after roof complete
Getting roof on fast is critical path item

What Comes Next

After completing roofing:

Window and door installation - Make house weathertight
Exterior finishing - Siding, trim, exterior doors
Rough-in trades - Can begin once weathertight
Gutters - After siding complete

Typical gap between phases: Windows can start immediately

Link to: Windows and Doors Phase

Related Resources

Need Roofing Help?

Roofing is critical to protecting your investment. If you're unsure about any aspect of roof installation, a consultation or hiring a professional is worthwhile.