Williamstown is a former coal town in the Wiconisco Creek valley, and 402 of its 638 homes were built in 1939 or earlier. Our crew repairs and replaces the roofs on those houses, slate and shingle alike.
Williamstown has about 0.3 square miles of land and roughly 1,345 people. It sits about 26 miles northeast of downtown Harrisburg-Carlisle. We cover ZIP code 17098.
No completed roof in Williamstown is logged in our job records yet.
Williamstown sits at about 866 feet in the valley of Wiconisco Creek, with Big Lick Mountain to the north and Berry Mountain to the south. It was settled in 1869. Anthracite mines and hosiery mills once employed most of its workforce, and the colliery closed in 1942. Most of its houses were already standing by then: 63% were built in 1939 or earlier, and the Census counts just 3 built from 2010 to 2019 and none since. Roofs on houses that old often rest on wood boards rather than plywood, and some carry an older roof under the one you see.
The NWS 1991–2020 normals for the Harrisburg station at Harrisburg International Airport in Middletown give about 101.1 days a year with a low at or below 32°F and 18.7 days with a high at or below 32°F. In Williamstown, snow piles up on roofs in winter, and where an old attic lets the house's heat through, meltwater runs down to the cold eaves and freezes into ice dams that push water under the shingles. Humid summers then feed moss and algae on the slopes that stay damp longest.
Heating matters on these roofs in another way. Of Williamstown's 572 occupied homes, 314 heat with fuel oil and 40 with coal, so many chimneys here work all winter, and the flashing and mortar where a chimney passes through the roof take steady wear. The Census also counts 93 single-family houses attached to a neighbor, and on those the roof often continues across the party wall. When we re-roof one of them, our written scope marks where our work stops at that wall and how the new roof meets the one next door.
On houses this old in Williamstown the deck is usually solid boards, not plywood, and boards shift: gaps open, nails work loose, and a shingle nailed over a gap holds on to nothing. Chimneys and wall joints often still carry their original step and counter-flashing, which is where many leaks really start while the shingles look fine. Two or three roofs piled on one another are common on streets like these; every extra layer hides the deck, adds weight and voids most manufacturer warranties. Any original slate or tile on the house calls for a different plan from an asphalt tear-off.
By the Census Bureau's estimate there are 638 homes in Williamstown, with a median year built of 1939 or earlier, the oldest band the survey reports. 402 of them (63%) went up before 1940 — the 4th-highest pre-1940 share of the 37 places on this site — and 3 (0%) in 2000 or later. More of today's homes date from before 1940 than from any decade since. (Dauphin County as a whole: 19% before 1940.)
The Residential Rehabilitation Inspection Guide from the U.S. Department of Housing and Urban Development puts the service life of a roof's first layer at about 20 years. By that measure, 100% of Williamstown's homes — the 635 built before 2000 — are past their first roof, and 90% (576 homes) go back before 1970, two roof lives and more. Older houses are where a second layer laid over the first turns up, and that layer is what hides soft decking.
62% of homes in Williamstown are single-family detached houses (395) and 15% attached ones such as townhouses (93). 135 homes (21%) sit in two- to nine-unit buildings. 358 of 572 occupied homes (63%) are lived in by their owners. On a housing mix like this, the work can include full tear-offs on houses past two roof lives, deck and flashing checks on pre-war board sheathing and flat and low-slope sections, which turn up more on attached and multi-unit buildings.
| Built | Homes | Share | |
|---|---|---|---|
| Before 1940 | 402 | 63% | |
| 1940s | 74 | 12% | |
| 1950s | 62 | 10% | |
| 1960s | 38 | 6% | |
| 1970s | 42 | 7% | |
| 1980s | 4 | 1% | |
| 1990s | 13 | 2% | |
| 2000s | 0 | 0% | |
| 2010s | 3 | 0% | |
| 2020 or later | 0 | 0% |
Census ACS 2020–2024, tables B25034, B25035, B25024 and B25003: 638 homes, 572 occupied. Survey estimates.
NOAA’s Storm Prediction Center logged no reports of hail 1 inch or larger within 5 miles of Williamstown’s center from 2016 through 2025. That is a gap in the reports rather than proof that no hail fell: reports come from spotters and the public.
Williamstown publishes no rule either way on a like-for-like re-roof, so we ask the building department before we start and pull whatever it wants.
Williamstown does not publish the code edition it currently enforces. We confirm the edition with the building department before we write the scope.
What goes into a new roof, layer by layerDesign wind here is set by location, not one figure for the whole area: across the Harrisburg-Carlisle, Pennsylvania metro, we build to the design wind speed set for the address; Township of Upper Allen’s published table gives 90 mph. The building department for Williamstown can tell you which figure applies. What it does to a roof is in the roofing code guide.
| City | Re-roof permit | Code | Median built |
|---|---|---|---|
| Williamstown | Not published | Not published | 1939 or earlier |
| Colonial Park | Not published | UCC (2021 IRC) | 1969 |
| Unincorporated Dauphin County | Not published | UCC (2021 IRC) | — |
| Elizabethville | Not published | Not published | 1951 |
| Enhaut | Not published | UCC (2021 IRC) | 1950 |
| Harrisburg | Yes | Not published | 1947 |
| Hershey | Not published | UCC (2021 IRC) | 1970 |
Every Dauphin County city we cover, side by side →
Ice dams start with heat. When warmth from the rooms below gets into the attic, it melts the underside of the snow on the roof, and the water runs down to the cold eaves and freezes there, backing water up under the shingles. With 402 of Williamstown's 638 homes built in 1939 or earlier, many attics here date from long before today's insulation and ventilation rules, so sealing and insulating the attic floor can matter as much as new shingles.
Often it can. Slate itself is long-lived, and on many old slate roofs the trouble starts at the nails, the flashing or a few cracked or slipped pieces, which can be replaced one at a time. Whether repair makes sense depends on how much of the slate is still sound and on the boards beneath it, which on a house built in 1939 or earlier deserve a close look from the attic before anything is decided.
Williamstown does not publish a clear answer either way. We confirm it with the building department before starting and pull whatever is required.
By the Census Bureau's estimates, 100% of Williamstown's homes were built before 2000 and 90% before 1970, with a median year built of 1939 or earlier (2020–2024 estimates). A roof usually lasts about 20 years, so the deck and the layers get checked before any quote.
Not yet: no completed roof in Williamstown is in our job records, so this page shows no job count.
Researched 2026-11-09; housing, Census ACS 2020–2024; hail, NOAA SPC. Sources: data.census.gov · data.census.gov · data.census.gov · www2.census.gov · www2.census.gov · data.census.gov · data.census.gov · en.wikipedia.org · www.spc.noaa.gov. Rules and staff change; check with the jurisdiction.