What factors determine the cost of a roof?
Replacing a roof is one of the costliest upgrades a homeowner can make.
Roofing contractors look at several variables to determine the price of a new roof, including its size, pitch, accessibility and cost of materials. Because of this, prices for a new roof can range drastically.
In terms of a ballpark figure, though, Michael Allen, owner of Above It All Roofing in Irvine, California, says the average cost of a new roof runs as low as $5,000 for an asphalt shingle roof — the most commonly used roofing material in America — to $25,000 and up for higher-end roof types. The average price, he says, is $12,000.
Angie’s List members reported paying an average of $11,095 to tear off and replace an old roof in 2014. Prices can also vary greatly depending on where you live.
“We’ve done [asphalt shingle] roofs for the Housing Authority here in Charlotte for lower-income people for as low as $4,000,” says Dan Hood, sales and marketing manager for H & S Roofing Company in Charlotte, North Carolina. “And [now] we’re in the process of putting on a $150,000 slate roof.”
Roof size affects costs
A roof’s size is the largest cost factor, Hood says.
Roofers charge per roofing square. A 10-by-10-foot (100 square feet) area is equal to one roofing square.
“For example, if we’re working on a roof that is 3,000 square feet, it’s broken down into 30 squares,” Allen says.
Expect to pay more if your roof is higher than most or difficult to access. (Photo courtesy of Oliver Jeromin, of Holland, Michigan)
Pitch of the roof impacts price
Another variable in pricing is the roof’s pitch, or slope. Some roofs have a high pitch, while others have a low pitch or no pitch at all — all factors which affect the cost of the roofing project.
Allen says a roof with a pitch of about a 7:12 ratio — the first number represents the height and the second the length — or higher isn’t walkable and may require extra safety harnesses and equipment. A 7:12 roof, for example, means that for every 12 inches it runs horizontally, the roof rises 7 inches vertically.
“A roof of 7:12 or greater is a steep roof, and we charge more money for that,” Allen says. “The work just goes a lot slower with a steep roof. You can’t stack stuff on the roof, and you have to wear harnesses.”
Hood says H & S Roofing also charges more for pitches above 7:12 because of the difficulty and because the company pays more in insurance costs.
Another factor is accessibility to the roof.
“Can we get a truck in there [close to the house]?” Allen says. “Can we back the truck against the house? If not, we’ll have to carry [the materials] all the way out to the trucks, and that can be more expensive.”
Tearing off a heavier roof can also increase labor costs.
Type of roofing material matters
According to Homewyse, which provides average costs for home improvement projects, the cost per square foot for a shingle roof is between $5.43 and $7.05. That equates to about $1,086 to $1,409 per 200 square feet (or for two squares).
Homewyse estimates the cost and labor for an asphalt roof for a 1,200-square-foot house in larger markets across the country ranges between $4,100 and $6,000.
Highly rated roofing contractors tell us that asphalt is the most affordable roofing option, followed by wood, tile, metal, and slate. Materials for a metal roof can cost up to $350 to $1,500 per 100 square feet. Angie’s List members recently reported paying an average of $12,236 for a metal roof installation.
“You can pay twice as much for a metal roof compared to asphalt shingles, and as much as five times more for slate,” Hood says.
While asphalt shingles may last 20 or more years, tile, metal and slate may last 50 or more years, which can play a role in determining the type you want.
Other roofing cost factors
Water damage can also add to the final costs of a roofing project. Oftentimes, water damage isn’t noticed until after the roofer has removed shingles and looked at the deck.
Significant water damage can also change the project from a roofing repair to a replacement. Another factor that can affect the price is whether your home has chimneys or skylights. Having them can increase the cost of the project, as roofers must work around them.
The cost of repairing flashing around the chimney can range from $200 to $500, while repairing it around the skylight can average between $300 and $500. Another possibility to keep costs down is shingling over an existing roof instead of replacing it, but this typically lowers its lifespan by 20 percent.
Hiring a roofer
Before hiring a roofing company, the National Roofing Contractors Associationrecommends checking that its workers are licensed and insured. Ask to see a copy of the roofer’s proof of insurance.
The contractor may also need to pull permits depending on where you live, which can add several hundred dollars onto the project. A permit to repair a roof on a 1,350-square-foot home, for example, costs between $150 and $400.
The roofer should also be aware of any local building codes, which could include the types of shingles allowed in a particular neighborhood or rules about underlay.
Seek out several bids, and don’t just settle for the lowest one. Sometimes a bid that is too low could be a signal the company isn’t operating legally.
“Look at their online feedback,” Allen says. “Bottom line, make sure the company has a good reputation.”
Many roofers offer guarantees for the work they do, which is often between five and 10 years for their workmanship. This will typically cover leakage or total failure, but not general wear and tear or damage from hail or storms. Some companies offer 25-year warranties, but those typically apply to specific high-end roof products and require certain installation procedures.