The median home in Kennett was built in 1991; there are 3,715 of them. 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
Under 34 Pa. Code § 403.1(b)(8), alterations to a house that make no structural change are outside the state code. Whether Kennett wants a permit is in its own ordinance; ask the township code office before the old roof comes off.
Source: 34 Pa. Code § 403.1(b)
Layers
IRC R908.3.1.1 forbids roofing over two existing layers, over slate or tile, or over a water-soaked roof. 38% of Kennett’s homes were built before 1980, so count the layers before comparing quotes.
Ice barrier
Whether an eave membrane is a code item depends on the climate table the municipality filled in when it adopted the code (IRC R905.1.2, Table R301.2). Ask the township code office or the contractor what Kennett’s says.
Checked against the code text on October 24, 2026. The state’s code edition and the rest of its rules: roof replacement in Pennsylvania.
Of 3,580 occupied homes in Kennett, 2,762 (77%) are owner-occupied. Counting by decade, 8% before 1940, 18% before 1960, 38% before 1980 of the housing was in place, and 33% dates from 2000 on. (ACS 2020–2024.)
The housing is 64% detached houses, 19% attached single-family houses (rowhouses, twins and townhouses).
33% of homes here were built in 2000 or later. HUD’s useful-life table gives an asphalt-shingle roof 20 years, so roofs on houses from the early 2000s are reaching that age.
Of the 71 Chester County municipalities on this site, Kennett has the 43rd largest share of homes built before 1980: 38%, against a county range of 12% to 80%.
ZIP codes: 19317 · 19348
| Place | Median built | Before 1980 | Owners | Row, twin | Hail days |
|---|---|---|---|---|---|
| Kennett | 1991 | 38% | 77% | 19% | 10 |
| Kennett Square | 1957 | 75% | 56% | 15% | 11 |
| East Marlborough | 1988 | 34% | 92% | 19% | 15 |
| Pennsbury | 1983 | 42% | 81% | 14% | 15 |
| New Garden | 1994 | 26% | 77% | 7% | 12 |
| Pocopson | 1986 | 42% | 99% | 13% | 17 |
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 Kennett, topping out at 1.75 in on July 25, 2010. The most recent was June 16, 2023.
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; 64% 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; 8% 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 (19% of homes here are attached) | Where the roof meets a wall or parapet |
Before signing for a roof in Kennett, 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).
Contracts, deposits and the right to cancel: checking a roofing contractor. What moves the price: new roof cost in Pennsylvania.
Kennett’s ordinance decides. Under 34 Pa. Code § 403.1(b)(8), alterations to a house that make no structural change are outside the state code. Whether Kennett wants a permit is in its own ordinance; ask the township code office before the old roof comes off.
IRC R908.3.1.1 forbids roofing over two existing layers, over slate or tile, or over a water-soaked roof. 38% of Kennett’s homes were built before 1980, so count the layers before comparing quotes.
By the Census Bureau’s American Community Survey (2020–2024), the median home in Kennett was built in 1991, 38% of homes were built before 1980, 77% are owner-occupied.
Hail of 1 inch or larger was reported on 10 days within 10 miles of Kennett 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 Kennett, 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.