Home Improvement Exterior Remodel Roof

The Basics of Roof Replacement

Cost, Materials, Replacement Options, and How It Works

Construction workers on a roof of home

Steven Puetzer / Photographer's Choice RF / Getty Images

Roof replacement is one of the most important of all major home repairs. You have many things to consider when replacing a roof, but you never want to let an old roof fail; water can destroy the inside of your home, from the attic insulation down through the painstakingly remodeled kitchen, right on through to the basement family room with a big-screen TV. Fewer home problems can be more disastrous than a failed roof.

Roof replacement is not something to take lightly, nor is it a repair you should delay. It's not too difficult to replace or repair a single shingle, but if one shingle fails, it's a good idea to inspect your roof to check the rest of its integrity.

You might also need a permit in your state or locality to repair a roof, depending on the size of the area and the type of repairs. A permit may also be required when reroofing. When you sense that your roof is nearing the end of its useful life, brush up on these basics before soliciting bids from roofing contractors.

Signs You Need a New Roof

Certain signs will let you know when your home needs a new roof. Here are few of the most important indications.

  • Curling shingles: Shingles tend to curl in one of two ways—either on their edges, called cupping, or in the middle, called clawing. This warping can eventually lead to leaks.
  • Gutter granules: If you spot loose granules in your gutters while cleaning the need for a new roof may be imminent. These are the remnants of materials that are on top of your shingles protecting your roof from sun damage.
  • Cracked shingles: Damaged or missing shingles are a tale-tell sign sections of your roof may be compromised. Usually these can be repairs but if there are several areas in need, it may be time to replace the entire roof.
  • Old Age: If your roof is well over 20 years old, your home may be in store for a new one. Most asphalt shingle roofs are in need or repair or replacement once this old.
  • Attic Light: If significant light beams are coming through your attic ceiling or you spot water stains, it may be time for a new roof. A roofing professional can assess your roof and let you know if you need a new one.

Roof Replacement Cost

How much it costs to replace a roof in your state depends on your choice of roofing materials, the roofing contractor you choose, the pitch (steepness or your roof), and the square footage of your roof.

Roofing Costs by Type

The type of materials used greatly influences the cost of the roof. Rock-bottom, a three-tab composite roof for a small home may cost as little as $6,000, according to Angi. Replacing a typical roof using architectural asphalt shingles costs between $3 and $6 per square foot nationally, including demolition, permit fees, waste disposal, and cleanup. Not everyone gets asphalt shingles; other materials vary. Architectural shingles or slate will raise the overall cost. The national average for roof replacement ranges from $4 to $11 per square foot.

Typical Average Costs of Different Roofing Options
 Material Average Cost
 Three-tab asphalt shingles  $6,000 to $13,000
 30-year shingles  $9,000 to $15,000
 50-year shingles  $11,000 to $20,000
 EPDM rubber  $8,000 to $14,000
 TPO or PVC membrane  $10,000 to $15,000
 Wood shingles  $14,000 to $25,000
 Steel shingles  $14,000 to $25,000
 Aluminum shingles  $15,000 to $28,000
 Standing-seam steel roofing  $23,000 to $30,000
 Natural slate  $25,000 to $50,000
 Concrete tile  $20,000 to $40,000
 Clay tiles  $25,000 to $50,000

Full vs. Partial Roof Replacement Costs

Replacing part of your roof will be less costly than replacing the whole thing. When roofers only need to remove the damaged singles in a section and replace them with new ones, it's much less invasive and requires less material resulting in a much lower quote.

A full-roof replacement when your roof is severely damaged or simply at the end of its lifespan will be much more expensive. Every old shingle and piece of roof material will need removal taking more time and effort. Labor and material costs will increase significantly.

In certain situations, the cost per square foot for a partial roof removal and replacement can be higher than that of a complete roof replacement project. This is because expenses such as debris removal and permits remain fixed, regardless of whether it's a partial or full roof replacement.

Cost to Replace Roofing vs. Repair

Typically a roof repair will cost much less than a roof replacement. On average a roof repair will cost between $382 and $1829 while a full replacement falls in the range of $5,848 to 12,879. In many instances, a repair will be all that is needed. A small leak in a roof that's relatively new or in good condition otherwise, a minor hole, or improperly installed flashing are all things that can be repaired.

It's important to note that although the idea of saving money is appealing you'll want to make sure it's the best option. Depending on the issue, a roof repair may only provide temporary relief that will give way to the need for replacement eventually. Sometimes it might be best to bite the bullet and go ahead with the new roof. It will cost more upfront but save you in the long run.

Tip

When seeking professional roof replacement or repair estimates, make sure to ask about any warranties. Warranties should be offered not only on the materials used but on the installation and labor as well. Knowing how long those last and if anything would void them such as pressure washing or inadequate attic ventilation will help you make the most informed decision when accepting a quote for roofing work.

Additional Costs to Consider

In addition to labor and materials, there will be other costs to consider when budgeting for a roof repair or replacement. These include permit fees, roof inspection, a premium for expedited services in the case of an emergency, and additional damage you may have in gutters or metal flashing.

The Basic Roofing Materials

Choosing roof replacement options often depends on your locality and your preference. For example, metal roofing is a standard selection in some regions due to its fire resistance. In contrast, the predominant home styles in other areas might call for a Spanish-influenced tile. Roof pitch (angle) also affects the roofing materials you can use. For example, wood shake shingles can be used for steeper-pitched roofs but are unsuitable for flatter, low-pitched roofs.

The most common choices for residential roofing include: 

  • Asphalt composition shingles:  These are cheap and easily obtainable but less attractive than other options due to their flat appearance. This roofing type is by far the most popular roofing material.
  • Wood shakes or shingles: These are pricey but attractive shingles. They have excellent durability but aren't a good choice in regions with fire danger. 
  • Metal Roofing: Metal roofs made of steel or aluminum have become more prevalent in recent years due to their durability and fire resistance. These expensive roofs require specialty contractors for installation, but they may be cost-effective over the long run due to their long life. Several types of metal roofing systems are available, including raised-seam panels and products that mimic the look of composite shingles. 
  • Slate roofing: This is a desirable, high-end roofing option, but it is expensive and heavy. Slate roofs are extremely slippery to walk on and difficult to repair when damaged. 
  • Composition slate: These synthetic tiles made from 95 percent recycled materials, including rubber, are gaining popularity. They closely resemble slate and other forms of stone tile but are much lighter and less susceptible to damage.  
  • Clay or ceramic tile: Long the most predominant image in Southern California and Florida, the Spanish-style red tile roof is still common but gradually replaced by metal and composite materials that mimic the Spanish tile look. Other roofing materials that meet ceramic tile's fire retardant ability are now available, with much less weight put on the roof. This type of shingle is called the "half-barrel" because it is essentially a cylinder cut in half length-wise, roughly 16 inches long.

According to the American Society of Home Inspectors, costlier slate, copper, and tile roofs last 50 years and more. Wood shake roofs endure about 30 years, fiber cement shingles have a life of nearly 25 years, and asphalt shingle composition roofs last about 20 years.

Tear Off or Second Layer?

It was once common to lay a new shingle roof over the preexisting layer at least once or sometimes even twice. This roofing practice is no longer allowed in some jurisdictions, where complete tear-off of the previous roofing is now required. Even where layering is allowed, applying a new layer of shingles over the old should be carefully considered based on its pros and cons: 

  • Weight: The main argument against laying additional layers of asphalt shingles is that the roofing materials can get too heavy for the underlying roof framing. Excessive weight can cause structural problems, especially for older houses. A triple layer of asphalt shingles is often equal to a single layer of slate shingles—an exceedingly heavy material.
  • Telegraphing: Another problem with shingling over existing shingles is repeating some surface irregularities that may already be present. If you're contemplating putting on a new roof, there's probably a good chance you may have bubbles, bumps, and waves that should be remedied. Putting new shingles over existing problems can leave you with a rather unattractive new roof. One way to minimize this problem is to go over the old roof and correct as many issues as possible before re-roofing. It doesn't take much more than a hammer, some roofing nails and a handful of shingles to correct bumps, gaps, and protruding nails.
  • Work and waste reduction: The primary advantage of layering is that it reduces the work involved. Stripping off the existing layer and then laying down a new layer adds more work to the process. Time isn't a problem if roofing professionals tackle the job because they can strip most roofs in the morning. But if you're doing the job yourself, it can be a strong argument for roofing over the old roof. 
  • Manufacturer's warranties: Some types of roofs and manufacturers require that roofs under warranty be stripped entirely to comply with the rules and restrictions of the warranty. If the roof is currently under warranty, check what the warranty requires.

When to Get a Roof Replacement

While in most parts of the United States, the optimal roofing season is from late spring to early fall, skilled crews can extend the work season, sometimes even roofing when snow flurries are threatening.

There is no reason not to hire a skilled crew to roof your home during off-season periods. You may get lower prices at these times since the labor demand is low. The trick behind getting your roof job shoehorned into the offseason is having a large team of professional roofers who can knock out the work in hours instead of days, thus taking advantage of dry periods. 

Understand the Roofing Process

If you understand the steps to replacing a roof and the jargon used in the roofing trade, you'll be able to make an informed decision when hiring a roofing crew. A moderately-sized, professionally-installed roofing job might take only three or four days.

Here's the usual process: 

  1. Remove all existing shingles; deposit them in a roll-off dumpster: Damaged or old valley flashing and drip edging are also removed at this time. A good crew will use tarps to protect foundation plantings and shrubs during tear-off and will use magnetic tools to pick up nails and metal objects from the lawn. 
  2. Make minor repairs on the roof if it is in good condition: If not, replace bad wood with new plywood sheathing or 1 by 6 sheathing boards, whichever applies to your type of roof. 
  3. Install ice dam protection in regions that require it: The ice guard membrane is a synthetic waterproof barrier material designed to prevent melting ice from backing up under the shingles and penetrating through the sheathing, where the moisture can cause severe damage.
  4. Lay down asphalt roofing paper over the roof sheathing: The layer of roofing paper creates an inner barrier against water penetrating the house. Rows of roofing paper are overlapped as they progress upward toward the peak and are normally tacked or stapled in place. 
  5. Apply metal drip edging around the roof's edge, both the eave and gable sides: The metal drip edge is nailed over the roofing paper or ice guard. 
  6. Where necessary, apply a new valley flashing along with areas where two roof planes meet: The valley flashing is typically nailed to the roofing deck and sealed with roofing caulk.
  7. Apply the tab shingles, starting at the eaves and working upward toward the peak: Where roof vents are being installed, tab shingles are installed starting from the bottom, moving upwards.
  8. Apply the flashing around all areas where leaks might come into the house—against the chimney, around skylights and stack vents, etc.: Flashing installation may happen as part of the roofing installation, occurring as the rows of shingles progress upward on the roof deck. 
  9. Install the ridge vent: This continuous vent along the roof's peak will help the air circulation in the attic space and can be integral in exhausting hot air and preventing winter ice dams. Ridge vents may not be included on older roofs, but installing them is a good idea whenever a house is re-roofed. If ridge vents are not practical, other types of roof or gable vents should be installed to provide air circulation in the attic space. 
  10. Complete the final cleanup and haul the debris away: Have a building inspector inspect and approve the installation.

The roofing business uses some special terminology when estimating materials for a roofing job. 

  • The term "square," when used in the roofing business, is a unit of area. One square equals 100 square feet.
  • Shingles come in "bundles." Three or four bundles of shingles typically will cover a square of roofing area.

DIY Roof Replacement vs. Hiring a Professional

Roof replacement is an extensive undertaking and unless you're a professional roofer yourself, it's typically not recommended. Not only will you need to know and obtain all of the materials to get the job done but you'll have to remove the old roof and put the new one on securely. This be hazardous work for the homeowner and DIYers may lack the expertise to identify issues such as hidden damage, leaks, or structural problems that potentially appear through the process. Hiring a professional roofer with the training and knowledge will ensure that you do not have problems down the road due to improper material selection or incorrect installation.

Warning

There are a lot of safety hazards involved in roof repair and replacement and any DIY work should be undertaken with the knowledge of the risks involved. Roofing accidents result in a number of severe injuries annually and are fatal in some cases.

FAQ
  • Can you put a new roof over an old roof?

    This process of putting new shingles over existing ones that are in good condition is called re-roofing. It is possible if your existing shingles meet the conditions required for re-roofing. If your roof is nearing the end of its lifespan but the sheathing board and underlying elements are still in good condition, you could be a candidate for re-roofing. As long as shingles aren't missing, curling or leaking and you are not changing to a new material, re-roofing can work well.

  • What is the average lifespan of a roof?

    A roof made up of typical asphalt shingles will last between 20 and 25 years. Materials such as concrete, slate or clay tiles can last up to 50 years or more.

  • What time of year is best for roof replacement?

    Late Autumn and early Spring are usually regarded as the best seasons for roof replacement. Winter can bring frigid temperatures to work in as well as inconsistent and inclement weather. Summer can be too hot and humid affecting the adhesives and sealants that need the right conditions to set properly.

The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. How much does a roof replacement cost [2023 data]?. Angi.

  2. How much does roof replacement cost?. Angi.

  3. How Much Does a Tile Roof Cost?. American Society of Home Inspectors.

  4. Alternative Roofing Materials. U.S. Department of Agriculture.

  5. Fatalities on the Rise in the Roofing Industry: What's Behind the Numbers - April 2020. Florida Roofing and Sheet Metal Contractors Association.