A roof is a system, not a layer of shingles. Under the shingles sits underlayment and, in cold regions, an ice and water barrier along the eaves. At every wall, chimney, and vent there is flashing. Along the ridge and soffit there is ventilation that decides how hot the attic gets and how fast the shingles age. A cheap job usually skips or thins one of those.
Age and symptoms decide repair versus replacement. This Old House puts the line near 15 years: an older roof with leaks, curling or missing shingles, or moisture problems is usually a replacement; a roof under 10 years old with a few wind-displaced shingles is usually a repair.
Asphalt shingles are the default for a reason: they are the lowest cost and most roofers know them well. Metal costs roughly three to four times as much per square foot and lasts longest. The right choice depends on how long you will stay and how visible the roof is.
What it costs
| Material | Per sq ft | Total (2,000 sq ft) | Typical lifespan |
|---|---|---|---|
| Asphalt shingles | $5.02 | $10,042 | 30 to 35 years |
| Wood shake | $12.69 | $25,376 | 30 to 50 years |
| Metal | $18.64 | $37,285 | 40 to 70 years |
| Clay tile | $21.37 | $42,743 | 50 to 100 years |
These are builder-grade figures for a standard low-slope roof with medium labor, from Homewyse via This Old House. In the same guide, This Old House puts the average at $15,439 for a 2,000 sq ft asphalt roof. Labor was about 65% of the total in their survey, which is why steep pitch and complex shapes move the price.
What moves the price
- Material
- Asphalt, metal, tile, and slate span an order of magnitude in price.
- Roof size and shape
- Measured by roof area, which is larger than floor area. Valleys, dormers, and skylights add labor and waste.
- Pitch and height
- Steep or tall roofs need extra safety equipment and slow the crew down.
- Hidden damage
- In the This Old House survey, 23% of homeowners who found hidden damage paid more than their original estimate, compared with 13% who did not.
- Ventilation and ice barrier
- Ridge vents, baffles, and ice and water shield add material and labor but protect the whole system.
Signs it is time
- Shingles that are curled, cracked, or missing granules in the gutters
- Water stains on a ceiling or in the attic
- Daylight visible through the roof boards from the attic
- Sagging sections or soft spots when walked on by an inspector
- Rusted or lifting flashing at chimneys, walls, and vents
- Roof older than about 15 to 20 years with any of the above
Questions to ask a pro
- Is this tear-off or an overlay, and what do local codes allow?
- Which underlayment and ice and water barrier are in the price?
- How is damaged decking priced if it is found during tear-off?
- Are drip edge, flashing, pipe boots, and ridge vents replaced or reused?
- What is the workmanship warranty, and what does the shingle warranty actually cover?
- Who handles the permit and the dumpster, and what is the cleanup plan for nails?
Go deeper: Full guide: roof replacement cost in 2026
Go deeper: Local guide: roof replacement in the Baltimore area
Common questions
Can a second layer of shingles go on top?
Most building codes allow two layers of asphalt shingles, and an overlay can be faster and cheaper. It makes sense for a roof in good shape with localized damage, but it hides the deck and shortens the new roof's life, so many pros prefer tear-off.
Will insurance pay for a new roof?
Sudden damage from a storm or a fallen tree can be covered; wear and age usually are not. Check your policy and call your insurer before you sign a contract.
How long does a replacement take?
In the This Old House survey, most projects took around a week from start to finish. Simple asphalt roofs can go faster; metal and tile usually take longer.