The Roof Replacement Process, Step by Step (2026)

A new roof is a big project, and most homeowners have never watched one happen. So the day the crew shows up, the noise and the flying debris can feel alarming, even when everything is going right. The truth is that a quality roof replacement follows the same clear order every time, from the first inspection to the last nail swept off your driveway. This guide walks you through all 12 steps so you know exactly what to expect, how long it takes, and how to tell a good crew from a bad one.

Quick answer: A roof replacement follows the same order every time: a free inspection and written estimate, then you choose materials and sign a contract. The roofer pulls permits, delivers materials, and protects your property. The crew tears off the old roof, inspects and repairs the decking, then installs drip edge, underlayment, and ice-and-water shield, flashing, shingles, and a ridge vent. They finish with a full cleanup, a magnetic nail sweep, a final inspection, and your warranty paperwork. Most asphalt roofs take one to three days.

The 12 steps of a roof replacement, at a glance

Before we go deep, here’s the whole job in order. A reputable roofer hits every one of these, even if they don’t narrate each step out loud. Knowing the sequence is the easiest way to spot a crew that’s skipping work to cut corners.

Key takeaway: Every quality replacement runs through these 12 steps in order. If a quote or a crew skips tear-off, decking inspection, new flashing, or fresh underlayment, you’re buying a shortcut that will cost you later.

Now let’s break each one down so you know what good work actually looks like.

Step 1: Inspection and a written estimate

Every roof replacement starts with a real inspection, not a number scribbled from the curb. A pro climbs onto the roof or flies a drone, checks the shingles, flashing, valleys, and ventilation, looks in your attic for leaks and daylight, and measures the roof in squares. (A roofing square is 100 square feet; see our explainer on what a roofing square is.) Then they put it all in a written, itemized estimate.

A good estimate is specific. It lists the tear-off, the exact shingle brand and line, the underlayment and ice-and-water shield, new flashing, ventilation, cleanup, and both warranties. It also flags the things nobody can price exactly yet, like rotted decking, usually as a per-sheet rate.

Key takeaway: A trustworthy quote is detailed and in writing. A one-line “$14,000 for a new roof” with no breakdown is a warning sign, not a deal.

This is also the moment to compare a few pros instead of trusting the first one. Onward matches you with a few vetted local roofers so you get fair, written quotes side by side, without handing your number to ten cold-callers. You can get a free quote in about 60 seconds, or read our full guide on how much a roof costs first.

Step 2: Choosing materials and signing the contract

Once you’ve picked a roofer, you’ll choose your materials. For most homes that means an asphalt shingle line and a color, but you might also weigh upgrades like architectural shingles, an impact-resistant class 4 product, or a metal roof. Your roofer should bring samples and show you how colors look against your siding and trim.

Then comes the contract, and this is the document that protects you. Read it closely before you sign. A solid roofing contract spells out:

1. The exact materials and brands, down to the shingle line and underlayment type.
2. The full scope: tear-off, decking repair rate, flashing, ventilation, and cleanup.
3. The total price and a milestone-based payment schedule.
4. Start and finish dates, plus who pulls the permit.
5. Both a workmanship (labor) warranty and the manufacturer (material) warranty, in writing.

Watch the deposit. A modest down payment to order materials is normal; a demand for a large cash payment up front is a red flag. Our guide on how to hire a roofer covers contract terms and deposits in detail.

Key takeaway: If a price, material, date, or warranty isn’t written in the contract, it doesn’t exist. Never rely on a verbal promise.

Step 3: Pulling permits

Most towns require a building permit to replace a roof, and your contractor should pull it, not you. The permit triggers a code inspection that confirms the work was done right, which is exactly the protection you want as a homeowner.

Permit rules vary by city and county, and so does the timeline. In some areas a roofing permit is same-day; in others it takes a week or more, which can push your start date. Your roofer should know the local process cold and build it into the schedule.

Here’s the part to pay attention to: if a roofer asks you to pull the permit, or suggests skipping it to save money, walk away. According to Bob Vila’s guidance on roofing permits, unpermitted work can fail inspection, void warranties, and cause headaches when you sell the home. A licensed pro handles this without blinking. Every roofer in the Onward network is license-verified through The Onward Shield, so permit dodging isn’t on the table.

Key takeaway: The contractor pulls the permit. Anyone trying to skip it is often unlicensed or trying to avoid the inspection that protects you.

Step 4: Material delivery and protecting your property

A day or two before tear-off, a truck drops your shingles and materials, often loading them right onto the roof or staging them in the driveway. Crews sometimes deliver early in the morning, so this is when you’ll want cars moved out of the way.

The day work starts, a good crew spends real time on site prep before a single shingle comes off. Per installation guidance from manufacturers like IKO, careful prep is what separates a clean job from a damaged yard. That prep includes:

• Tarping shrubs, flower beds, and the lawn around the house to catch debris.
• Leaning plywood against the walls and covering the AC unit.
• Protecting the driveway and positioning a dumpster or dump trailer for haul-away.
• Closing the gutters off or planning to clean them out at the end.

If a crew starts ripping shingles with no tarps down and no protection in place, that tells you how much they’ll care about the rest of the job.

Key takeaway: Watch the first 30 minutes. A crew that protects your landscaping, driveway, and AC before tear-off is a crew that respects your home.

Step 5: Tearing off the old roof

Tear-off is the loud, messy heart of the project. The crew strips your home down to the bare decking, pulling off old shingles, underlayment, and flashing and dropping it into the dumpster below. On a typical home, tear-off runs about four to six hours, and the hammering and scraping will be constant.

Why tear off at all instead of laying new shingles over the old ones? A full tear-off lets the crew inspect the decking, install fresh underlayment and flashing, and gives you the longest-lasting result. Roof-overs are sometimes legal but they hide problems, add weight, and can shorten the life of the new roof, which is why most quality contractors and manufacturers recommend a full tear-off.

Expect dust to drift into the attic and the whole house to feel like it’s under a drum line. This is normal. What’s not normal is the crew tearing off more roof than they can cover before the end of the day or before rain.

Key takeaway: Full tear-off down to the deck is the gold standard. A “roof-over” that buries the old shingles is cheaper today and a problem tomorrow.

Step 6: Inspecting and repairing the decking

With the roof stripped bare, the crew inspects the decking, the plywood or OSB sheets nailed to your rafters. This is the foundation everything else sits on, and it has to be solid. They walk it, feeling for soft, spongy, or rotted spots, and look for water stains, mold, and sagging.

Any bad boards get cut out and replaced with new sheathing. This is the most common “surprise” cost on a roof job, because nobody can see rotted wood until the old roof is off. That’s why a good estimate lists decking repair as a per-sheet rate up front, so you’re not blindsided by the price.

Here’s where being reachable matters. If the crew finds widespread rot, they should stop and call you before piling on charges. A pro shows you photos and explains the fix; a bad actor quietly inflates the count and surprises you on the final bill.

Key takeaway: Decking repair is priced per sheet because no one can see rot until tear-off. Insist on photos and a call before any major repair charge is added.

Step 7: Drip edge, underlayment, and ice-and-water shield

Now the waterproofing base goes down, and the order matters. These layers are your roof’s real defense against water; the shingles on top are mostly the armor.

• Drip edge is metal flashing along the eaves and rakes. It directs water off the roof and into the gutter instead of behind it, and gives the shingles a clean edge to sit on. Fine Homebuilding notes that proper drip edge placement is one of the details that separates careful installers from sloppy ones.
• Ice-and-water shield is a self-sticking, waterproof membrane installed along the eaves, in the valleys, and around penetrations. In cold-winter regions, code often requires it along the eaves to fight ice dams. There’s a long-running debate (covered well by Fine Homebuilding and the NRCA) about whether it goes over or under the drip edge at the eaves; a good crew follows code and the manufacturer’s instructions.
• Underlayment is the layer that covers the rest of the deck. Most pros now use synthetic underlayment instead of old felt because it’s tougher and grips better.

Key takeaway: The underlayment and ice-and-water shield are what actually keep your house dry. Cutting corners here is invisible on day one and disastrous after the first hard freeze or wind-driven rain.

Step 8: Flashing the chimney, valleys, and vents

Flashing is the thin metal that seals every spot where your roof meets something else: chimneys, sidewalls, skylights, plumbing vents, and the valleys where two roof planes join. These joints are where the large majority of roof leaks start, so this step quietly makes or breaks the whole job.

A quality crew installs new flashing rather than reusing old, rusted pieces or just gunking up the seams with caulk. Each penetration takes time. Chimneys, skylights, and valleys often need custom-bent flashing, which is part of why a cut-up roof with lots of features takes longer than a simple gable. Our deeper explainer on flashing walks through each type.

Reused flashing and caulk-only “repairs” are among the most common shortcuts in the trade. They look fine the day the crew leaves and leak two seasons later, long after the cheap roofer is gone.

Key takeaway: New flashing at every joint is non-negotiable. If a quote reuses old flashing or relies on caulk, expect leaks around your chimney and valleys down the road.

Step 9: Installing the shingles

With the waterproofing and flashing done, the crew installs the actual roofing. They start with a starter strip along the eaves, then work up the roof in overlapping rows, nailing each shingle by the manufacturer’s pattern. Nail placement matters more than it sounds: too high or too few nails and shingles blow off in the first big wind, and it can void the warranty.

For asphalt shingles, this is usually the fastest-moving part of the job once the prep is done. Other materials take longer. Metal roofing and tile require specialized fastening and more careful handling, which is one reason they can stretch a one-day asphalt job into three or more.

*For an average home; varies by roof size, pitch, complexity, and weather.

Good installers follow the shingle maker’s exact specs, because that’s what keeps the manufacturer warranty valid. See our overview of types of shingles to understand your options.

Key takeaway: Nail count and placement decide whether your shingles survive the next windstorm. A crew that nails to the manufacturer’s spec protects both your roof and your warranty.

Step 10: Ridge vent and ridge cap

Near the end, the crew finishes the peak of the roof. They cut a slot through the sheathing along the ridge, install a ridge vent, and cap it with matching shingles, called ridge cap. The ridge vent lets hot, moist air escape from your attic while intake vents at the eaves pull cooler air in.

This matters more than most homeowners realize. Good attic ventilation keeps your shingles cooler so they last longer, lowers your summer cooling load, and cuts the risk of ice dams and attic moisture in winter. A quality replacement is the natural time to fix weak ventilation, so ask your roofer whether your current setup is balanced. Our roof ventilation guide explains how intake and exhaust work together.

Key takeaway: A ridge vent isn’t an upsell, it’s part of a complete roof. Skipping ventilation shortens shingle life and invites moisture problems in the attic.

Step 11: Cleanup and the magnetic nail sweep

The job isn’t finished when the last shingle is nailed. A professional crew breaks down the site, hauls every scrap of debris to the dumpster, clears the gutters of granules and nails, and does a full walk of your property.

The signature move is the magnetic nail sweep: the crew rolls a large magnet over your driveway, walkways, and lawn to pick up stray nails before they end up in a tire or a paw. Many pros do it twice. Then you should do your own slow walk of the perimeter before letting kids or pets back outside, since a stray nail in the grass is easy to miss.

A clean site is one of the clearest signs of a quality crew. Per homeowner-prep guidance from manufacturers and contractors alike, debris and nails left behind are the number-one post-job complaint, and they’re completely avoidable.

Key takeaway: No magnetic nail sweep, no finished job. Do your own walk of the yard and driveway before pets and kids go back out.

Step 12: Final inspection and warranty paperwork

Finally, the work gets checked and you get your paperwork. In most areas, a municipal building inspector visits to confirm the new roof meets code; this is the inspection your permit paid for. Your contractor (or a project manager) should also do a final walkthrough with you, pointing out the work and answering questions.

Then you should receive, in writing:

• The workmanship warranty from the roofer, covering installation defects (often 1–10+ years).
• The manufacturer warranty from the shingle maker like GAF or Owens Corning, covering material defects.
• Any registration paperwork needed to activate an enhanced manufacturer warranty.
• A final invoice and lien waivers showing suppliers and subs were paid.

Hold your final payment until the work passes inspection, the site is clean, and you have the warranty documents in hand. Our guide on roofing warranties explains what each one actually covers.

Key takeaway: Don’t make the final payment until the roof passes inspection, the yard is clean, and both warranties are in your hands in writing.

How long does the whole thing take?

Most asphalt shingle roofs on an average home are replaced in one to three days. A simple single-story gable roof can be done in a day; a larger, steeper, more cut-up roof often takes two or three. Metal and tile run longer, sometimes a week.

A few things stretch the timeline:

• Weather. Rain, high wind, or extreme heat pauses work for safety and proper installation.
• Roof complexity. Steep pitches, multiple valleys, dormers, chimneys, and skylights all add custom flashing and slow, careful work.
• Surprise decking rot. Replacing damaged boards adds hours.
• Crew size. A six-person crew moves far faster than three.
• Material lead times. Special-order shingles, metal, or tile can add days or weeks before the job even starts.

Expect a loud, disruptive day or two. Tear-off and nailing are constant noise, and your home will vibrate. It’s temporary, and a good crew keeps it as short and clean as possible.

Key takeaway: Plan for one to three days of asphalt work, longer for metal or tile, and build in a buffer for weather and any rotted decking found during tear-off.

Your roof replacement prep checklist

You don’t have to do much, but a little prep keeps your stuff safe and the crew moving. Run through this the day before:

• Cars: Move vehicles out of the driveway and away from the house. Deliveries can come early, and debris falls farther than you’d think.
• Driveway and yard: Clear patio furniture, the grill, potted plants, toys, and decor within about 15 feet of the house.
• Attic: Cover or move stored boxes; dust and small debris can sift through the deck, and vibration can shift stacked items.
• Inside: Take framed photos, mirrors, and fragile items off the walls and high shelves on the top floor. Hammering shakes the house.
• Pets: Keep pets indoors, away from the work zone, for the whole job and until you’ve checked the yard for nails.
• Kids: Plan for young kids to be elsewhere or in a ground-floor room far from the noise. The yard is off-limits during the work.
• Neighbors: Give a heads-up 2–3 days ahead about the noise and reduced street parking. Neighbors with pets or kids will thank you.
• Access: Make sure the crew can reach the roof, an outdoor outlet, and any attic access they need.

Key takeaway: The two prep steps homeowners skip most are clearing the attic and warning the neighbors. Both take five minutes and save real headaches.

Good crew vs. bad crew: what to watch for

You can read a roofing crew within the first hour, and again at the end. Here’s the side-by-side that homeowners wish they’d seen before they signed.

The single best protection is hiring a vetted pro in the first place. This is exactly the fear Onward exists to remove. Every roofer we match you with passes The Onward Shield, our six-point check: state license verified, liability and workers’ comp insurance verified, a background and track-record check, a required written workmanship warranty, real reviews from finished jobs plus the BBB, and a re-check every single year. Nearly 1 in 3 roofers who apply don’t get in. And every matched job is backed by The Onward Promise, our homeowner-protection guarantee. We never sell your info or hand it to ten callers; we send your details to only a few matched pros so you can compare fair written quotes and pick.

Key takeaway: The cleanest way to guarantee a good crew is to hire one that’s already vetted. Verify the license and insurance yourself, or let Onward’s six-point Shield do it for you.

The bottom line

A roof replacement isn’t a mystery once you know the order: inspect and quote, choose materials and sign, permit, prep, tear off, repair the decking, lay drip edge and underlayment and ice-and-water shield, flash every joint, install the shingles, vent the ridge, clean up with a nail sweep, and finish with a final inspection and your warranties. The work that protects your home most, the decking, underlayment, flashing, and ventilation, is the work you can’t see once the shingles go on. That’s exactly why hiring a crew you can trust matters more than the lowest bid.

Your next step is simple. Get a few fair, written quotes from vetted local pros, compare the scope, not just the price, and pick the one who does every step right. Onward makes that part easy and free.

Get a free quote and get matched with vetted local roofers →