Half of the 731 homes in Allentown were built before 1955. 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 Allentown, 74% 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. 87% of Allentown’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
New Jersey requires the eave membrane only where January averages 25 °F or colder, which the state says is Sussex County (DCA Bulletin 07-3). Allentown 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. The state’s code edition and the rest of its rules: roof replacement in New Jersey.
Owners live in 488 of Allentown’s occupied homes, or 72%. Counting by decade, 33% before 1940, 62% before 1960, 87% before 1980 of the housing was in place, and 3% dates from 2000 on. (ACS 2020–2024.)
The housing is 74% detached houses, 8% attached single-family houses (rowhouses, twins and townhouses), 6% buildings of two to four units.
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 48 Monmouth County municipalities on this site, Allentown has the largest share of homes built before 1980: 87%, against a county range of 22% to 87%.
| Place | Median built | Before 1980 | Owners | Row, twin | Hail days |
|---|---|---|---|---|---|
| Allentown | 1955 | 87% | 72% | 8% | 10 |
| Robbinsville | 1992 | 19% | 80% | 27% | 9 |
| Upper Freehold | 2000 | 22% | 97% | 2% | 9 |
| Hamilton Township, Mercer County | 1964 | 75% | 72% | 10% | 10 |
| Chesterfield | 2004 | 21% | 96% | 13% | 12 |
| North Hanover | 1994 | 29% | 45% | 31% | 10 |
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.
NOAA’s storm reports show 10 days since 2006 with hail of at least 1 inch inside a 10-mile circle around Allentown, topping out at 1.5 in on April 1, 2023.
At the county level, Allentown shares Monmouth County’s record of 7 storm disaster declarations since 2006, the newest 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.
Useful life is HUD’s planning figure, not a warranty. 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; 74% 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; 33% here predate 1940 | Never a base for a new layer (R908.3.1.1); heavy |
| Flat roof: EPDM or TPO | 15 years | Additions and porch roofs | Coating is not a replacement |
Ask a roofer working in Allentown 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). In Allentown, 74% 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 Allentown was built in 1955, 87% of homes were built before 1980, 72% are owner-occupied.
Hail of 1 inch or larger was reported on 10 days within 10 miles of Allentown 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 Allentown 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.