Half of the 2,353 homes in Lambertville were built before 1938. The rules below decide how much of the old roof has to come off and what goes under the new one.
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). In Lambertville, 26% of homes are detached. An attached house, or work on rafters and beams, is not covered.
Source: N.J.A.C. 5:23-2.7
Layers
New Jersey deletes the IRC’s reroofing definitions (N.J.A.C. 5:23-3.21(c)2.xxii); its layer rule for existing houses is in the Rehabilitation Subcode, which this site has not read yet. 70% of Lambertville’s homes were built before 1980: ask how many layers yours has and whether the price is for a tear-off to the deck.
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). For Lambertville, ask whether the quote includes one anyway.
Source: N.J.A.C. 5:23-3.21; NJ DCA Bulletin 07-3
Rules as read on October 24, 2026. The state’s code edition and the rest of its rules: roof replacement in New Jersey.
Owners live in 1,761 of Lambertville’s occupied homes, or 78%. By year built, 52% before 1940, 55% before 1960, 70% before 1980; 9% went up in 2000 or later. (ACS 2020–2024.)
By building type: 26% detached houses, 45% attached single-family houses (rowhouses, twins and townhouses), 14% buildings of two to four units.
With 45% 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.
On a house built before 1940, ask what the deck is (boards or plywood) and whether slate sits under the later layers: slate can’t be roofed over.
Of the 23 Hunterdon County municipalities on this site, Lambertville has the 5th largest share of homes built before 1980: 70%, against a county range of 27% to 93%.
| Place | Median built | Before 1980 | Owners | Row, twin | Hail days |
|---|---|---|---|---|---|
| Lambertville | 1938 | 70% | 78% | 45% | 10 |
| West Amwell | 1975 | 54% | 89% | 2% | 10 |
| Delaware | 1981 | 48% | 97% | 2% | 13 |
| Hopewell Township, Mercer County | 1977 | 53% | 91% | 9% | 8 |
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 Lambertville, hail of an inch or more was reported on 10 days between 2006 and 2025, the biggest stones 1.75 in on May 29, 2019. The most recent was September 8, 2023.
Remnants of Hurricane Ida (DR-4614, September 2021) is the latest of 8 federal storm declarations covering Hunterdon County since 2006. (OpenFEMA.)
A report says hail fell near Lambertville, not that it damaged a roof. When wind or hail damage means a new roof.
HUD’s useful-life figures are for planning; a warranty is a separate promise. For Lambertville’s houses: 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; 26% 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 | Simple roofs with long, unbroken slopes | Standing seam that carries its own loads can skip the tear-off (R908.3.1) |
| Slate | 75 years | Older houses; 52% here predate 1940 | Can’t be roofed over; check the framing for the weight |
| Flat roof: EPDM or TPO | 15 years | Low-slope roofs and rear sections (45% of homes here are attached) | Coating is not a replacement |
Any business offering home improvements in Lambertville must be registered with the New Jersey Division of Consumer Affairs, with the number on its contracts and ads (N.J.S.A. 56:8-138, 56:8-144); 47,473 registrations were active in October 2026.
The price side is in what a new roof costs in New Jersey; the paperwork side in checking a roofing contractor.
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). In Lambertville, 26% of homes are detached. An attached house, or work on rafters and beams, is not covered.
By the Census Bureau’s American Community Survey (2020–2024), the median home in Lambertville was built in 1938, 70% of homes were built before 1980, 78% are owner-occupied.
Hail of 1 inch or larger was reported on 10 days within 10 miles of Lambertville from 2006 through 2025 (NOAA Storm Prediction Center). A report means hail fell nearby, not that a roof was damaged.
Any business offering home improvements in Lambertville must be registered with the New Jersey Division of Consumer Affairs, with the number on its contracts and ads (N.J.S.A. 56:8-138, 56:8-144); 47,473 registrations were active in October 2026.
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.