In O'Fallon, 5% of the 13,530 homes went up before 1940. We replace and repair roofs here and inspect after hail, starting with a free, photographed inspection.
O'Fallon runs to about 15.7 square miles and roughly 32,289 people. It sits about 15 miles east of downtown St. Louis. The community dates back to 1874. We cover ZIP codes 62269 and 62225.
No completed roof in O'Fallon is logged in our job records yet.
O'Fallon's housing is spread across many named platted subdivisions (Thornbury Hill, Nolin Creek Estates, Fairwood Hills, Deer Creek, Forest Hills, Fairwood East), reflecting late-20th-century subdivision-driven growth after the city's 1854 founding.
We work across O'Fallon rather than one corner of it — Thornbury Hill, Nolin Creek Estates, Fairwood Hills, Deer Creek, Forest Hills and Fairwood East included. Age and construction change between them, which is why we look before we quote.
O'Fallon was founded in 1854 and incorporated as a village in January 1874, adopting a city form of government in 1905. It sits near Scott Air Force Base, which has driven much of its subdivision growth.
Housing from this stretch in O'Fallon sits on plywood or OSB decking and was largely first roofed with three-tab shingles. Most are on their second covering by now. The things worth checking are the penetrations rather than the field: pipe boots from this era are the single most common leak we trace, because the rubber collar splits long before the shingles wear out. Ridge venting was inconsistent through these years, and OSB that has been damp for a season goes soft in a way plywood does not — you find it with your feet, not from the ground.
By the Census Bureau's estimate there are 13,530 homes in O'Fallon, with a median year built of 1997. 731 of them (5%) went up before 1940 — 24th of 48 places on this site for pre-1940 share — and 6,037 (45%) in 2000 or later. The 2000s were the busiest decade, adding 3,292 of today's homes (24%). Across St. Clair County the pre-1940 share is 13%, so O'Fallon sits below it.
The rule of thumb from Missouri's Department of Commerce and Insurance is a useful life of usually about 25 years for a roof. By that measure, 55% of O'Fallon's homes — the 7,493 built before 2000 — are past their first roof; 2,187 of them (16%) predate 1970, old enough for two replacements already. The 3,292 homes from the 2000s are where first replacements come up now, while the 2,745 built since 2010 are mostly still on the roof they were built with.
Detached single-family houses make up 67% (9,008); attached houses and townhouses 8% (1,071). 1,777 homes (13%) sit in two- to nine-unit buildings and 1,242 (9%) in buildings of ten units or more, where a resident rarely gets to choose the roofer. The count also takes in 423 mobile homes, which are a different kind of roof job. 8,997 of 12,816 occupied homes (70%) are lived in by their owners. With houses like these, the jobs we expect most are first replacements on 2000s builder-grade shingles, flat and low-slope sections, which turn up more on attached and multi-unit buildings and hail checks on newer roofs that look fine from the driveway.
| Built | Homes | Share | |
|---|---|---|---|
| Before 1940 | 731 | 5% | |
| 1940s | 139 | 1% | |
| 1950s | 482 | 4% | |
| 1960s | 835 | 6% | |
| 1970s | 1,342 | 10% | |
| 1980s | 1,592 | 12% | |
| 1990s | 2,372 | 18% | |
| 2000s | 3,292 | 24% | |
| 2010s | 2,403 | 18% | |
| 2020 or later | 342 | 3% |
Census ACS 2020–2024, tables B25034, B25035, B25024 and B25003: 13,530 homes, 12,816 occupied. Survey estimates.
Between 2016 and 2025 there were 15 reports of 1-inch-plus hail within 5 miles of O’Fallon’s center in the records of NOAA’s Storm Prediction Center, on 8 separate days. 3 of them were 1.75 inches or larger. The largest, 1.75 inches, came on April 2, 2025, about 1.4 miles north of the center. Counts follow people as much as storms, since every report is a spotter’s or a resident’s.
| Latest reports | Size | From center |
|---|---|---|
| April 2, 2025 | 1.75 inches | 1.4 mi N |
| March 14, 2025 | 1 inch | 3.6 mi S |
| March 14, 2025 | 1 inch | 0.8 mi SE |
| March 14, 2025 | 1 inch | 1.4 mi N |
| March 14, 2025 | 1 inch | 3.1 mi SE |
If one of those storms crossed your street and nobody has been on the roof since, a storm inspection photographs what it did.
O'Fallon publishes no rule either way on a like-for-like re-roof, so we ask the building department (618-624-4500) before we start and pull whatever it wants.
O'Fallon does not publish the code edition it currently enforces, so this page does not name one. Editions across the metro run from the 2006 IRC to the 2024 IRC — worth asking any contractor which one they are building to.
The published number is 618-624-4500. O'Fallon does not publish the building official's name, so this page does not name one. Plenty of sites will show you one anyway. The department page is here.
The design figures are metro-wide rather than local: 115 mph ultimate design wind and a 20 psf ground snow load. What they do to a roof is in the roofing code guide.
Also in St. Clair County:
| City | Re-roof permit | Code | Median built |
|---|---|---|---|
| O'Fallon | Not published | Not published | 1997 |
| Belleville | Not published | Not published | 1962 |
| Fairview Heights | Not published | Not published | 1972 |
| Swansea | Yes | 2006 IRC | 1993 |
All 4 St. Clair County cities side by side →
O'Fallon does not publish a clear answer either way. We confirm it with the building department before starting and pull whatever is required.
The Census Bureau's 2020–2024 estimates put the median year built at 1997: 5% of O'Fallon's 13,530 homes predate 1940 and 45% were built in 2000 or later. At the usual 25-year roof life, 55% have needed at least one new roof already.
Yes. The most recent report of hail 1 inch or larger within 5 miles of O'Fallon's center was 1.75 inches on April 2, 2025, one of 15 such reports from 2016 through 2025.
Not yet: no completed roof in O'Fallon is in our job records, so this page shows no job count.
Researched 2026-09-09; housing, Census ACS 2020–2024; hail, NOAA SPC. Sources: www.ofallonillinois.org · www.ofallon.org · codelibrary.amlegal.com · codes.iccsafe.org · en.wikipedia.org · www.bestplaces.net · data.census.gov · www.spc.noaa.gov. Rules and staff change; check with the jurisdiction.
