A replacement is more than new shingles. These are the lines a complete quote should show, in the order the work happens. Where the code requires a line, the rule is named.
1. Tear-off
The code's starting point is "removal of existing layers of roof coverings down to the roof deck" (IRC R908.3). A recover over one existing layer is allowed in some cases; over two layers, slate, tile, or a water-soaked roof it is not (R908.3.1.1). The quote should say which it is, how many layers come off, and that disposal is included. Tear-off or roof over.
2. The deck
With the old roof off, the deck is visible. Damaged sheathing is replaced by the sheet. Philadelphia's reroof certification asks the contractor to state whether less than 10% of the sheathing was replaced (form TP_019_F). Ask how the quote prices deck sheets: a number included, or a price per sheet.
In Florida, on a site-built single-family house permitted before March 1, 2002, a full replacement must include re-nailing of the deck to the code's schedule (Fla. Stat. § 553.844(3); FBC Existing Building 706.7).
3. Deck-joint tape (Connecticut)
Connecticut requires a 4-inch strip of self-adhering membrane over all joints of a plywood or OSB deck, under the underlayment ((Amd) R905.1.1), unless the whole deck gets a self-adhered membrane or the deck is boards under 3 feet wide.
4. Ice barrier
From the eave to at least 24 inches inside the exterior wall, a self-adhering membrane or two cemented layers of underlayment (IRC R905.1.2). Required in every town in Massachusetts, Connecticut and Rhode Island; in New Jersey only in Sussex County (DCA Bulletin 07-3); in Pennsylvania where the municipality's climate table says so. Ice barrier by state.
5. Underlayment
Over the whole deck. On asphalt shingles at a slope from 2:12 to 4:12, a double layer (IRC R905.2.2). In Florida, older houses get a secondary water barrier as well (§ 553.844(3)).
6. Flashing and edges
Drip edge at eaves and rakes, valley linings, step and counter flashing at walls and chimneys, and flashing around vents and skylights. The code sets flashing materials and leaves installation to the manufacturer's instructions (IRC R905.2.8). Ask whether existing flashing is reused or replaced.
7. The covering
Shingles with the wind class your town's design wind speed calls for (IRC Table R905.2.4.1), or metal, slate, tile or a membrane. Materials compared.
8. Ventilation
Ridge and soffit vents are often redone with the roof. Ask what the quote includes.
9. Permit and inspection
Who pulls the permit, and what it costs: none for a detached one- or two-family house in New Jersey; Philadelphia's EZ permit is $69; Boston's short form is "$20, plus $10 per $1,000 of estimated cost." Permits by state.
10. Cleanup
Magnetic sweep for nails, protection for plantings and siding, and the dumpster.
Gutters, skylights and chimneys
Whether gutters, skylight replacement or chimney flashing are part of a roof replacement depends on the quote, not on any law. Ask for each as a separate line so you can compare quotes.
Questions
What does a full roof replacement include?
In the order the work happens: tear-off and disposal, replacing damaged deck sheets, deck-joint tape in Connecticut, ice barrier where the code requires it, underlayment, flashing and edges, the new covering, ventilation, the permit and inspection, and cleanup.
Are gutters part of a roof replacement?
Whether gutters, skylight replacement or chimney flashing are part of a roof replacement depends on the quote, not on any law. Ask for each as a separate line so quotes can be compared.
Is flashing replaced with a new roof?
Flashing covers the drip edge, valleys, walls and chimneys, vents and skylights. The code sets flashing materials and leaves installation to the manufacturer’s instructions (IRC R905.2.8), so ask whether the quote reuses existing flashing or replaces it.
Does a new roof include new ventilation?
Ridge and soffit vents are often redone along with the roof. Ask what the quote includes.