What Is the Most Expensive Part of Replacing a Roof?

The Short Answer Depends on Your Roof

We price a lot of tired roofs in Ontario, Rancho Cucamonga, Chino and Eastvale. The question we hear most is simple. Where does all that money go? It depends on what is on your roof now and what you want on it next.

On a shingle roof, the crew is the biggest cost. RoofingCalculator says labor typically runs about 60% of a roof replacement. Its own example is a $9,000 job where about $5,400 is labor. Tearing off, carrying bundles up a ladder, flashing every pipe and wall, and cleaning up is slow, skilled work.

On a tile roof, the answer changes. Tile is heavy and costly to buy and set. But most concrete tile in the Inland Empire outlives the paper under it. So the biggest cost decision is not labor or material. It is whether you need new tile or just new underlayment.

The wild card is the wood. Nobody can see the wood under your roof until the old roof is off. Rotten decking can turn a fair quote into a bigger bill on day one.

Where the Money Goes on a Typical Roof

HomeGuide breaks a replacement into three parts per square. A square is 100 square feet of roof. Old roof removal runs $100 to $300 a square. Roof materials run $100 to $250 a square. Replacement labor runs $200 to $350 a square. Labor is the largest of the three at both ends of the range.

The same guide lists a California average of $6,200 to $17,400 for a new roof, and permits at $100 to $500 depending on the city (HomeGuide, accessed October 2026). These are national guide numbers, not our prices. Steep pitch, two story walls, and lots of hips and valleys push a roof toward the top of every range.

The table below is a worked example for a roof with 2,000 square feet of surface, which is 20 squares. It multiplies the published ranges. It is not a quote, and a real roof can land outside it.

Tile Roofs Flip the Math

Thousands of homes here were built with concrete tile in the 1980s, 1990s and 2000s. Tile often lasts for decades. The underlayment under it does not. HomeGuide says most roof underlayment needs replacing after 20 to 30 years.

That gives you two very different jobs. A re-lay, which some roofers call a lift and relay, means the crew lifts your tile, replaces the paper, and sets the same tile back. HomeGuide lists underlayment replacement on a tile roof at $0.75 to $4.00 per square foot for labor and materials, and $1,100 to $9,000 for the job. A full retile with new tile runs $10,500 to $62,500 on the same page.

So on our 2,000 square foot example, a re-lay works out to about $1,500 to $8,000 at those rates. New concrete tile at $7 to $19 per square foot installed (HomeGuide) works out to $14,000 to $38,000 before old tile removal. That gap is the most expensive line most Ontario homeowners can avoid.

A re-lay is not always the right call. HomeGuide suggests a full replacement when 20% to 30% of the tiles need work. We also look for tile that crumbles at the edges, old tile that no longer makes a match, and a homeowner who wants a new look. Our tile roofing page walks through the re-lay step by step.

The Hidden Cost Is the Wood Under the Roof

Decking is the plywood or OSB the roof is nailed to. RoofingCalculator puts replacing or repairing it at $2.20 to $3.00 per square foot. HomeGuide says $2 to $5 per square foot installed. A standard sheet is 4 by 8 feet, or 32 square feet. At those rates one sheet works out to roughly $70 to $160.

The catch is in the decking. RoofingCalculator notes that a contractor cannot tell if the decking is damaged until the old roof is removed, so that work gets added after you already have a quote. That is why a quote that looked cheap can grow.

In our dry climate, rot is not everywhere. It shows up where water has been sitting for years. Eaves under a clogged gutter. Valleys where worn paper let the winter storms through. The low side of a skylight or a chimney. A few soft sheets are normal on an old roof. A whole slope of mush means a leak was ignored for a long time.

The fix is to price it before work starts. Ask for a price per sheet in writing, so a surprise is a known number and not a blank check.

Tear Off and Haul Away

Taking the old roof off and getting rid of it is its own line. RoofingCalculator puts removal and disposal at $0.40 to $2.00 per square foot, or about $665 to $3,343 on an average job. It lists tile removal at $1.45 to $1.97 per square foot, nearly four times the rate for asphalt shingles at $0.39 to $0.53.

Other guides run higher. HomeGuide says $1 to $3 per square foot to tear off shingles or metal and $2 to $5 or more for heavy materials like tile. The sources do not agree, so ask your roofer to show removal as its own line.

Layers matter too. A second layer of old shingles means double the tear off and double the weight in the dump trailer. On a re-lay, the tile stays on site, so you skip most of the haul away cost for the heaviest material on the roof.

Permits and California Rules That Touch the Price

The City of Ontario issues reroof permits for detached single family homes through an online portal, and both contractors and homeowners can apply (City of Ontario). The page does not list a fee. National guides put roof permits at $100 to $500 (HomeGuide). Make sure the permit is a line in your quote, not a surprise.

California's energy code also reaches your roof. The California Energy Commission cool roof handout says the rules apply when more than half of the roof is replaced. For steep roofs in the inland climate zones it lists an aged solar reflectance of at least 0.20 and thermal emittance of at least 0.75, or an SRI of 16. It also lists exceptions on reroofs, like R-38 ceiling insulation or a radiant barrier in the attic. The same handout notes that cool rated tile, metal and asphalt come in a wide range of colors, including dark shades.

Last, the law caps what you pay up front. Under California B&P Code 7159, the down payment on a home improvement contract may not exceed $1,000 or 10% of the contract price, whichever is less. A roofer asking for half the job before a tile comes off is a red flag.

How to Keep the Biggest Line in Check

You cannot make labor cheap without making it worse. What you can do is make sure you are paying for the right job. On tile, ask whether your tile can be reused before anyone prices new tile. On any roof, get removal, decking, permit and cleanup as their own lines, so you can compare quotes fairly.

If you are not sure what you need, start with a roof inspection. Photos of your underlayment, flashing and soft spots tell you whether you are looking at a repair, a re-lay or a full roof replacement.

If your home is in Ontario or nearby, call Ontario Roofing at (909) 404-9464 for a free written estimate with photos of your roof. Our Ontario roofing page covers the neighborhoods we work in.