When a roof needs replacing
Roofs don't fail all at once. They wear out gradually, and the signs are usually visible from the ground or the attic long before a major leak. Watch for:
- Granules in the gutters and bare, shiny patches on asphalt shingles, which mean the protective surface is wearing away.
- Curling, cupping or cracked shingles, especially on the sunniest slopes.
- Missing shingles after wind, or shingles that lift easily.
- Sagging along the ridge or between rafters, which can point to structural or decking problems and needs prompt attention.
- Daylight in the attic, or stains and damp insulation under the roof deck.
- Repeated leaks in different places, which suggest the roof as a whole is failing rather than one spot.
Age matters, but condition matters more. Two roofs of the same age can be in very different shape depending on the material, ventilation, sun exposure and how well they were installed.
Choosing a roofing material
- Asphalt shingles are the most common choice for houses. Architectural (laminated) shingles are thicker and generally last longer than older three-tab styles.
- Concrete and clay tile are heavy and long-lived, and common in California. The tiles often outlast the underlayment beneath them, so a "tile roof replacement" sometimes means lifting and resetting the tiles over new underlayment.
- Metal roofing, either standing seam or metal shingles, sheds snow well and lasts a long time, at a higher initial cost.
- Low-slope roofs on additions, porches and some modern homes use membranes such as TPO, PVC, modified bitumen or built-up roofing rather than shingles.
Ask the contractor to explain why they recommend a material for your house, how it handles your local climate, and what the manufacturer warranty actually covers.
Tear-off or overlay?
Some jurisdictions allow a second layer of shingles over the first. A full tear-off costs more but lets the contractor inspect and repair the roof deck, replace flashings properly and install new underlayment and ice barrier where needed. Overlays add weight and can hide problems. Ask what your local code allows and what the contractor recommends for your roof.
Ventilation and the attic
A roof needs a balanced ventilation system: intake at the eaves and exhaust near the ridge. Poor ventilation shortens shingle life, traps heat in summer and moisture in winter, and in snowy climates contributes to ice dams. A replacement is the best time to correct ventilation.
Permits and inspections
Re-roofing usually requires a permit, and many jurisdictions inspect the work. Ask who pulls the permit and whether the price includes it. If your area has specific requirements, such as fire-rated roofing in wildfire-prone areas or ice barrier along the eaves in snow country, the contractor should explain them.
What a complete re-roof includes
1. Removal of old roofing to the deck (for a tear-off) and disposal. 2. Inspection and replacement of damaged decking, priced per sheet in the contract. 3. New underlayment, plus ice and water barrier where required or recommended. 4. New drip edge, valley flashing, step and wall flashing, and pipe boots. 5. Ventilation installed or corrected. 6. The new roofing installed to the manufacturer's specifications. 7. Cleanup, including a magnetic sweep for nails. 8. Written warranty information for both materials and workmanship.
Questions to ask
- Will you tear off the old roof, and how will you handle damaged decking?
- Which underlayment, flashing and ventilation will you use?
- Who pulls the permit, and when is the inspection?
- What does the workmanship warranty cover, and for how long?
- How will you protect landscaping and clean up afterward?