Roof replacement, leak repair and hail & storm damage for homes in Alton. In Alton, the 2021 IRC is in force and 28% of the 12,551 homes went up before 1940. It starts with a free inspection that photographs every slope.
Alton runs to about 15.7 square miles and roughly 25,279 people. It sits about 20 miles north of downtown St. Louis. The community dates back to 1837. We cover ZIP code 62002.
No completed roof in Alton is logged in our job records yet.
Alton's housing mixes pre-1940 Victorian-era homes (about 28%) with a large 1950s postwar wave (about 21%).
That includes Upper Alton. Housing age and construction shift across Alton, sometimes by decades within a few streets, which is why we look at the roof before we quote rather than after.
Many blocks of Alton were built in the Victorian Queen Anne style during the city's 19th-century steamboat-era prosperity, and the city still has an unusually high number of brick-paved streets. The Great Flood of 1993 cut off Alton's water supply for weeks and flooded the historic downtown.
Postwar houses in Alton are plain to roof, which is exactly why so many get roofed carelessly. Expect 1x6 board decking or early plywood: usually sound, but it should be walked, not assumed. The weak spots are the shallow pitches — a porch roof, the join to a carport, the flat section over an addition — where shingles went on below their rated slope and have leaked slowly for years. Attics from this era rarely have the ventilation today's shingle warranties ask for, and a hot, under-vented attic ages a roof from below, so intake and exhaust get measured before the quote.
The Census Bureau counts 12,551 homes in Alton, with a median year built of 1953. 3,459 of them (28%) went up before 1940 — 6th of 48 places on this site for pre-1940 share — and 1,001 (8%) in 2000 or later. More of today's homes date from before 1940 than from any decade since. (Madison County as a whole: 15% before 1940.)
About 25 years is the usual working life of a roof, by the figure Missouri's insurance department publishes. That puts 11,550 homes in Alton, the 92% built before 2000, past at least one full roof life; 9,204 of them (73%) predate 1970, old enough for two replacements already. First replacements are arriving on the 706 homes built in the 2000s, while the 295 built since 2010 are mostly still on the roof they were built with. On houses that old, the question worth asking is how many layers are up there: a roof laid over an old one hides the deck.
By building type: 9,453 detached houses (75%), 245 attached (2%). 1,538 homes (12%) sit in two- to nine-unit buildings and 959 (8%) in buildings of ten units or more, whose roofs are normally an owner's or a board's call rather than a resident's. The count also takes in 356 mobile homes, which are a different kind of roof job. 6,419 of 10,714 occupied homes (60%) are lived in by their owners. With houses like these, the jobs we expect most are full tear-offs on houses past two roof lives and deck and flashing checks on pre-war board sheathing.
| Built | Homes | Share | |
|---|---|---|---|
| Before 1940 | 3,459 | 28% | |
| 1940s | 2,057 | 16% | |
| 1950s | 2,585 | 21% | |
| 1960s | 1,103 | 9% | |
| 1970s | 1,420 | 11% | |
| 1980s | 446 | 4% | |
| 1990s | 480 | 4% | |
| 2000s | 706 | 6% | |
| 2010s | 236 | 2% | |
| 2020 or later | 59 | 0% |
Census ACS 2020–2024, tables B25034, B25035, B25024 and B25003: 12,551 homes, 10,714 occupied. Survey estimates.
NOAA’s Storm Prediction Center logged 4 reports of hail 1 inch or larger within 5 miles of Alton’s center from 2016 through 2025, on 4 different days. None was 1.75 inches or larger. The largest, 1.25 inches, came on October 9, 2017, about 2.5 miles southeast of the center. The most recent was 1 inch on August 12, 2025. Counts follow people as much as storms, since every report is a spotter’s or a resident’s.
| Latest reports | Size | From center |
|---|---|---|
| August 12, 2025 | 1 inch | 2.8 mi SE |
| July 17, 2023 | 1 inch | 3.5 mi NW |
| May 20, 2018 | 1 inch | 4.8 mi SE |
| October 9, 2017 | 1.25 inches | 2.5 mi SE |
Hail damage rarely shows from the ground; a storm inspection photographs each slope so you know either way.
Alton publishes no rule either way on a like-for-like re-roof, so we ask the building department (618-463-3500) before we start and pull whatever it wants.
Alton enforces the 2021 IRC. Alton City Code Section 9-1-3 amends the 'ICC International Residential Code 2021' and 'ICC International Building Code 2021 Edition.' It was most recently amended by Ordinance 7970, December 18, 2024.
The published number is 618-463-3500. The building official on record is Greg Caffey, Building and Zoning Director. The department page is here.
Wind 115 mph (ultimate) and ground snow 20 psf, the same across the metro; see the roofing code guide for what they govern.
Alton borders West Alton, Missouri and Grafton.
Also in Madison County:
| City | Re-roof permit | Code | Median built |
|---|---|---|---|
| Alton | Not published | 2021 IRC | 1953 |
| Collinsville | Yes | 2021 I-Codes | 1971 |
| Edwardsville | Not published | 2021 IRC | 1986 |
| Glen Carbon | Not published | Not published | 1990 |
| Granite City | Not published | 2012 IRC | 1957 |
All 5 Madison County cities side by side →
Alton does not publish a clear answer either way. We confirm it with the building department before starting and pull whatever is required.
Alton enforces the 2021 IRC. Alton City Code Section 9-1-3 amends the 'ICC International Residential Code 2021' and 'ICC International Building Code 2021 Edition.' It was most recently amended by Ordinance 7970, December 18, 2024.
Older than most people guess: the Census puts 92% of Alton's homes before 2000 and 73% before 1970, with a median year built of 1953 (2020–2024 estimates). A roof usually lasts about 25 years, so the deck and the layers get checked before any quote.
Yes. The most recent report of hail 1 inch or larger within 5 miles of Alton's center was 1 inch on August 12, 2025, one of 4 such reports from 2016 through 2025.
The building official on record is Greg Caffey, Building and Zoning Director. The department's own number is on this page, beside its name.
It can. Alton has Christian Hill Historic District, Upper Alton Historic District, Middletown Historic District and Downtown Alton Historic District. Inside a designated district, changing a visible roof material or color can need preservation review before the permit is issued. Like-for-like replacement usually raises fewer questions, but we check before quoting.
Not yet: no completed roof in Alton 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: cityofaltonil.gov · codelibrary.amlegal.com · cityofaltonil.gov · en.wikipedia.org · censusreporter.org · www.point2homes.com · data.census.gov · www.spc.noaa.gov. Rules and staff change; check with the jurisdiction.
