Half of the 4,339 homes in Westtown were built before 1981. 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)). So the township code office in Westtown is the one to ask before work starts.
Source: 34 Pa. Code § 403.1(b)
Layers
A new roof may go over one existing layer; with two or more, or over slate, clay or cement tile, everything comes off to the deck (IRC R908.3.1.1). 47% of Westtown’s homes were built before 1980; many have been reroofed before.
Ice barrier
IRC R905.1.2 calls for an ice barrier where Table R301.2 says so; in Pennsylvania the municipality completes that table. The contractor or the township code office in Westtown will know.
Checked against the code text on October 24, 2026. Everything else the state requires: roof replacement in Pennsylvania.
83% of the occupied homes in Westtown are lived in by their owners: 3,564 households, the people this line is for. Counting by decade, 6% before 1940, 18% before 1960, 47% before 1980 of the housing was in place, and 11% dates from 2000 on. (ACS 2020–2024.)
The housing is 73% detached houses, 11% attached single-family houses (rowhouses, twins and townhouses).
Of the 71 Chester County municipalities on this site, Westtown has the 27th largest share of homes built before 1980: 47%, against a county range of 12% to 80%.
ZIP codes: 19382
| Place | Median built | Before 1980 | Owners | Row, twin | Hail days |
|---|---|---|---|---|---|
| Westtown | 1981 | 47% | 83% | 11% | 15 |
| Thornbury Township, Chester County | 1994 | 27% | 77% | 26% | 15 |
| Thornbury Township, Delaware County | 1997 | 30% | 93% | 17% | 13 |
| West Chester | 1954 | 75% | 35% | 32% | 10 |
| West Goshen | 1978 | 53% | 72% | 10% | 10 |
| Birmingham | 1989 | 27% | 99% | 16% | 16 |
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 15 separate days within 10 miles of Westtown; the largest was 2.5 in on May 22, 2014. The most recent was April 4, 2025.
Chester County has had 5 federal major-disaster declarations for storms since 2006; the latest was DR-4618, 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; 73% 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 | Low pitches and long runs | A complete standing-seam system may go over the old roof (R908.3.1) |
| Slate | 75 years | Older houses; 6% 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 | Where the roof meets a wall or parapet |
A contractor who does $5,000 or more of home improvement work a year must be registered with the Pennsylvania Attorney General, and the number has to be on every contract and estimate (HICPA § 3, § 6). Ask for it before anyone starts on a roof in Westtown, and search it.
Contracts, deposits and the right to cancel: checking a roofing contractor. What moves the price: new roof cost in Pennsylvania.
Local ordinance, not the state. Pennsylvania’s code leaves residential alterations without structural change to local ordinance (34 Pa. Code § 403.1(b)(8)). So the township code office in Westtown is the one to ask before work starts.
A new roof may go over one existing layer; with two or more, or over slate, clay or cement tile, everything comes off to the deck (IRC R908.3.1.1). 47% of Westtown’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 Westtown was built in 1981, 47% of homes were built before 1980, 83% are owner-occupied.
Hail of 1 inch or larger was reported on 15 days within 10 miles of Westtown from 2006 through 2025 (NOAA Storm Prediction Center). A report means hail fell nearby, not that a roof was damaged.
A contractor who does $5,000 or more of home improvement work a year must be registered with the Pennsylvania Attorney General, and the number has to be on every contract and estimate (HICPA § 3, § 6). Ask for it before anyone starts on a roof in Westtown, and search it.
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.