Trenton has 34,513 homes, and half of them were standing by 1953. What the code requires when that roof is replaced, and who signs off, is below.
New Roofing Costs connects homeowners with independent local roofing contractors. We do not perform roofing work.
This number connects homeowners who are planning a new roof or a full roof replacement with independent local roofing contractors. It is not for leak repairs or patch jobs. The call must come from the homeowner who decides on the roof. Calls may be recorded.
Permit
New Jersey treats a new covering on a detached one- or two-family house as ordinary maintenance: no permit, no notice (N.J.A.C. 5:23-2.7). Attached houses (43% of Trenton’s homes) and any work that touches the structure fall outside the rule.
Source: N.J.A.C. 5:23-2.7
Layers
The state strikes the IRC reroof definitions from its code (N.J.A.C. 5:23-3.21) and leaves existing houses to the Rehabilitation Subcode, not yet checked here. With 79% of Trenton’s homes were built before 1980, ask the contractor to count the layers before quoting.
Source: N.J.A.C. 5:23-3.21
Ice barrier
Only Sussex County meets New Jersey’s 25 °F January test for a required ice barrier (N.J.A.C. 5:23-3.21; DCA Bulletin 07-3). Trenton is outside it, so whether to add one is up to you and the installer.
Source: N.J.A.C. 5:23-3.21; NJ DCA Bulletin 07-3
Checked against the code text on October 24, 2026. Code edition, permit and contract rules for the whole state: roof replacement in New Jersey.
Owners live in 12,152 of Trenton’s occupied homes, or 38%. Counting by decade, 38% before 1940, 60% before 1960, 79% before 1980 of the housing was in place, and 11% dates from 2000 on. (ACS 2020–2024.)
The housing is 16% detached houses, 43% attached single-family houses (rowhouses, twins and townhouses), 15% buildings of two to four units.
With 43% of homes attached, many roofs here meet a neighbor’s roof at a party wall. Say so on the call, and ask the contractor how the new roof will be tied in where it meets the house next door. New Jersey’s no-permit rule for reroofing covers detached houses only, so an attached house is outside it.
Older houses hide their history: ask the contractor to confirm the deck (board or sheet) and every layer above it before pricing, because slate or two layers mean a full tear-off.
Of the 12 Mercer County municipalities on this site, Trenton has the largest share of homes built before 1980: 79%, against a county range of 19% to 79%.
ZIP codes: 08608 · 08609 · 08611 · 08618 · 08629 · 08638
| Place | Median built | Before 1980 | Owners | Row, twin | Hail days |
|---|---|---|---|---|---|
| Trenton | 1953 | 79% | 38% | 43% | 10 |
| Ewing | 1964 | 72% | 67% | 7% | 12 |
| Hamilton Township, Mercer County | 1964 | 75% | 72% | 10% | 10 |
| Lawrence Township, Mercer County | 1979 | 51% | 68% | 19% | 10 |
| Bordentown | 1938 | 88% | 55% | 19% | 11 |
Median built: median year the homes were built. Before 1980: share of homes built then. Owners: share of homes that are owner-occupied. Row, twin: share of homes that are rowhouses, twins or townhouses. Census ACS 2020–2024. Hail days: days with hail of 1 inch or larger within 10 miles, 2006–2025, NOAA Storm Prediction Center.
Within 10 miles of Trenton, hail of an inch or more was reported on 10 days between 2006 and 2025, the biggest stones 1.75 in on July 6, 2020. The most recent was April 1, 2023.
Mercer County has had 9 federal major-disaster declarations for storms since 2006; the latest was DR-4614, Remnants of Hurricane Ida (September 2021). (OpenFEMA.)
Storm reports are what observers logged, not a measure of damage to any roof. When wind or hail damage means a new roof.
Lifespans come from HUD’s capital-needs table, not from a brochure. More in the guides to shingles, metal, slate and flat roofs.
| Material | HUD useful life | Fits a house like | Watch for |
|---|---|---|---|
| Asphalt shingles | 20 years | Most pitched roofs; 16% of homes here are detached | Wind class set by the design wind speed (IRC Table R905.2.4.1) |
| Metal (standing seam, panels) | 50 years | Roofs that will carry solar later | A complete standing-seam system may go over the old roof (R908.3.1) |
| Slate | 75 years | Older houses; 38% here predate 1940 | Never a base for a new layer (R908.3.1.1); heavy |
| Flat roof: EPDM or TPO | 15 years | Low-slope roofs and rear sections (43% of homes here are attached) | Where the roof meets a wall or parapet |
Ask a roofer working in Trenton for the New Jersey home improvement registration number, which the law requires on contracts and advertising (N.J.S.A. 56:8-138, 56:8-144), and look it up with the Division of Consumer Affairs.
Contracts, deposits and the right to cancel: checking a roofing contractor. What moves the price: new roof cost in New Jersey.
None for a detached one- or two-family house. New Jersey treats a new covering on a detached one- or two-family house as ordinary maintenance: no permit, no notice (N.J.A.C. 5:23-2.7). Attached houses (43% of Trenton’s homes) and any work that touches the structure fall outside the rule.
By the Census Bureau’s American Community Survey (2020–2024), the median home in Trenton was built in 1953, 79% of homes were built before 1980, 38% are owner-occupied.
Hail of 1 inch or larger was reported on 10 days within 10 miles of Trenton from 2006 through 2025 (NOAA Storm Prediction Center). A report means hail fell nearby, not that a roof was damaged.
Ask a roofer working in Trenton for the New Jersey home improvement registration number, which the law requires on contracts and advertising (N.J.S.A. 56:8-138, 56:8-144), and look it up with the Division of Consumer Affairs.
The full list: before you call.
Checked October 24, 2026. Laws and code editions change; the date says when these were last read at the source.