Replacing an Asphalt Roof? 3 Things to Get Right First

Before you replace an asphalt roof, three decisions do most of the work: the roofing system you install, the contractor who installs it, and the cost and warranty you agree to. Get those three right and you buy 25 to 30 years of quiet protection. Get them wrong and you can be back on a ladder, or on the phone with your insurer, far sooner than you should be.

Most people do not think much about their roof until it makes them. A stain blooms on a bedroom ceiling after a hard rain. Shingle grit shows up in the gutters. A neighbor's tear-off gets you looking up at your own curling, faded shingles for the first time in years. That moment, when a roof goes from background to front-of-mind, is exactly when good information matters most, because a roof replacement is one of the largest and longest-lasting investments a home will ask of you.

This guide walks through how to know it is time, the three things that decide whether the project lasts, and the questions worth asking before you sign anything.

How do you know it is time to replace an asphalt roof?

An asphalt roof is usually ready for replacement when it is near the end of its lifespan or showing several signs of failure at once. Roof damage is a slow process, so it pays to catch it before a leak reaches the inside of the home. Watch for:

• Age. 3-tab asphalt shingles last about 15 to 20 years; architectural shingles about 25 to 30. If your roof is 15-plus years old, get it inspected annually.
• Curling, cracking, or missing shingles, especially across broad areas rather than a single spot.
• Granules in the gutters or bald patches on shingles, a sign the protective surface is wearing off.
• Interior clues: ceiling or attic stains, peeling paint, damp walls, or daylight through the roof boards.
• Sagging or soft spots, which can point to moisture in the decking underneath.

You will not know for certain until a professional gets on the roof. A free, honest inspection tells you whether you are looking at a targeted repair or a full roof replacement, and it is the right first step before any decision about cost.

The 3 things that decide whether your new roof lasts

1. The roofing system, not just the shingles

A quality roof is a system, not a bundle of shingles. The shingles you see are one layer of several that keep water out, and skipping the hidden parts is how corner-cutting estimates get cheap. A complete asphalt roof includes:

• Underlayment over the decking as a secondary water barrier.
• Ice-and-water shield at the eaves, valleys, and penetrations, essential in Pennsylvania and New Jersey winters where ice dams form.
• Proper flashing at chimneys, walls, and valleys, where most leaks actually begin.
• Drip edge along the eaves and rakes. Some contractors omit it to lower a bid, which invites rot and leaks.
• Balanced attic ventilation, which lets heat and moisture escape so shingles do not cook from below and decking stays dry. Poor ventilation quietly shortens a roof's life.

Shingle grade matters too. Architectural (dimensional) shingles cost a little more than flat 3-tab shingles but last roughly a decade longer, resist wind better, and look far richer on the house, which is why they are the standard choice for most homes today. And it is worth comparing systems before you commit: asphalt shingles deliver the best value for most homeowners, while metal roofing and metal shingles cost more upfront but last for generations.

2. The contractor you hire

The single biggest variable in a roof's real-world lifespan is who installs it. The same shingle can last 30 years or fail in 10 depending on workmanship, so the contractor is a bigger decision than the brand. Look for:

• Manufacturer certification. Top-tier status, such as Owens Corning Platinum Preferred, is held by a small share of contractors and unlocks the strongest available system warranties. Exteriors by Global Home is an Owens Corning Platinum Preferred contractor.
• Proper licensing and insurance. Confirm state registration and current liability and workers' compensation coverage. GHI is licensed in PA (PA008490), NJ (13VH01194900), and DE, and has held an A+ BBB rating since 2004.
• A written, itemized estimate that lists the full system, tear-off, decking allowance, flashing, drip edge, and ventilation, not a single lump sum.
• Reasonable deposit terms. A deposit larger than about 30% is rarely necessary; be cautious of anyone demanding most of the cost upfront.

Multiple estimates are not about finding the cheapest number, they are about understanding the range of solutions and spotting the bid that quietly leaves out the parts that keep water out.

3. The cost, warranty, and financing

Price only means something once you know what is in it. A typical asphalt roof replacement runs about $5,000 to $15,000 nationally, with larger, steeper, or more complex roofs higher; full replacements across shingle and metal systems fall in the $10,000 to $40,000+ range in our own cost guides. What moves your number is roof size and pitch, how many old layers must be torn off, the condition of the decking underneath, and the system you choose.

Two warranties should come with the job, and they are not the same thing:

• Manufacturer (material) warranty covers defects in the shingles themselves.
• Workmanship warranty covers the installation. Exteriors by Global Home backs projects with the applicable manufacturer warranties plus our Platinum Plus Labor Warranty.

A new roof also returns real value, homeowners commonly recoup a large share of the cost at resale, and financing can spread the investment over time so the right system is not out of reach.

Asphalt vs. metal: a quick comparison

If you plan to stay in the home for decades, the longer life of standing seam or metal shingle can win on cost of ownership. For most homeowners on a shorter horizon, architectural asphalt remains the smart value.

The bottom line

A roof replacement is not the place to chase the lowest bid. Focus on the full system, hire a certified and properly insured contractor, and make sure the cost is transparent and the warranty is in writing. Do that, and your new asphalt roof will protect the home, and everything under it, for the next 25 to 30 years.

Exteriors by Global Home has installed and replaced roofs across Pennsylvania and New Jersey since 2001. If your roof is showing its age, request a free, no-obligation estimate and we will inspect it, explain your options honestly, and give you a written price built for your home. Not sure we cover your town? See our service areas.

Frequently asked questions

How long does an asphalt roof last?

3-tab asphalt shingles typically last 15 to 20 years; architectural shingles about 25 to 30. Ventilation, installation quality, and climate all affect the real number.

How much does it cost to replace an asphalt roof?

Roughly $5,000 to $15,000 nationally for a typical shingle roof, with complex or larger roofs higher; full roof replacements across shingle and metal systems run $10,000 to $40,000+ in our cost guides. Roof size, pitch, tear-off, decking condition, and system choice drive the price.

Should I repair or replace my asphalt roof?

Localized damage on a roof still within its lifespan usually means a repair. Widespread wear, multiple leaks, or a roof past 20 years generally points to replacement. An inspection settles it.

Is asphalt or metal roofing better?

Architectural asphalt offers the best balance of cost and lifespan for most homes. Metal costs more upfront but lasts 40 to 70 years and can pay off for long-term owners.

Is a new roof covered by homeowners insurance?

Often only when the damage is from a sudden, qualifying event like storm, wind, or hail. Normal aging is generally not covered; document damage and check your policy.

How long does a roof replacement take?

Most asphalt roofs are done in one to three days once materials arrive; size, complexity, weather, and decking repairs can extend it.