Allentown has 49,502 homes, and half of them were standing by 1952. Below: what the code asks of a replacement here, the permit, and the town’s own records.
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
Pennsylvania’s code leaves residential alterations without structural change to local ordinance (34 Pa. Code § 403.1(b)(8)). Whether Allentown wants a permit is in its own ordinance; ask the city code office before the old roof comes off.
Source: 34 Pa. Code § 403.1(b)
Layers
On a roof that already carries two layers, or slate or tile, the code allows no recover: it is a tear-off (IRC R908.3.1.1). 82% of Allentown’s homes were built before 1980; many have been reroofed before.
Ice barrier
The code requires an ice barrier where the local climate table (Table R301.2) says so, and each Pennsylvania municipality fills that table in. Ask the city code office or the contractor what Allentown’s says.
Rules as read on October 24, 2026. The state’s code edition and the rest of its rules: roof replacement in Pennsylvania.
Of 46,374 occupied homes in Allentown, 20,035 (43%) are owner-occupied. By year built, 38% before 1940, 62% before 1960, 82% before 1980; 9% went up in 2000 or later. (ACS 2020–2024.)
By building type: 26% detached houses, 36% attached single-family houses (rowhouses, twins and townhouses), 15% buildings of two to four units.
With 36% 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.
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 25 Lehigh County municipalities on this site, Allentown has the 5th largest share of homes built before 1980: 82%, against a county range of 22% to 90%.
ZIP codes: 18101 · 18102 · 18103 · 18109
| Place | Median built | Before 1980 | Owners | Row, twin | Hail days |
|---|---|---|---|---|---|
| Allentown | 1952 | 82% | 43% | 36% | 21 |
| Salisbury Township, Lehigh County | 1967 | 75% | 84% | 5% | 24 |
| South Whitehall | 1974 | 60% | 79% | 14% | 20 |
| Emmaus | 1955 | 78% | 64% | 25% | 21 |
| Catasauqua | 1938 | 87% | 74% | 37% | 24 |
| Fountain Hill | 1947 | 89% | 58% | 35% | 24 |
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.
Since 2006 the National Weather Service has logged hail of 1 inch or larger on 21 separate days within 10 miles of Allentown; the largest was 2.5 in on May 14, 2010. The most recent was July 3, 2025.
That is more hail days than 95% of the places in the state on this site.
Severe Winter Storm and Snowstorm (DR-4267, March 2016) is the latest of 2 federal storm declarations covering Lehigh County since 2006. (OpenFEMA.)
A report says hail fell near Allentown, not that it damaged a 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; 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; 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 (36% of homes here are attached) | Where the roof meets a wall or parapet |
Before signing for a roof in Allentown, get the contractor’s PA registration number: the home improvement law requires registration with the Attorney General above $5,000 a year of such work, and the number on contracts and estimates (HICPA § 3, § 6).
The price side is in what a new roof costs in Pennsylvania; the paperwork side in checking a roofing contractor.
Local ordinance, not the state. Pennsylvania’s code leaves residential alterations without structural change to local ordinance (34 Pa. Code § 403.1(b)(8)). Whether Allentown wants a permit is in its own ordinance; ask the city code office before the old roof comes off.
On a roof that already carries two layers, or slate or tile, the code allows no recover: it is a tear-off (IRC R908.3.1.1). 82% of Allentown’s homes were built before 1980; many have been reroofed before.
By the Census Bureau’s American Community Survey (2020–2024), the median home in Allentown was built in 1952, 82% of homes were built before 1980, 43% are owner-occupied.
Hail of 1 inch or larger was reported on 21 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.
Before signing for a roof in Allentown, get the contractor’s PA registration number: the home improvement law requires registration with the Attorney General above $5,000 a year of such work, and the number on contracts and estimates (HICPA § 3, § 6).
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.