In Affton, the 2015 IRC is in force and 9% of the 9,092 homes went up before 1940. We replace and repair roofs here and inspect after hail, starting with a free, photographed inspection.
Affton runs to about 4.6 square miles and roughly 19,052 people. It sits about 8 miles south of downtown St. Louis. We cover ZIP codes 63123 and 63125.
No completed roof in Affton is logged in our job records yet.
Affton's housing is largely postwar. The 1950s was the single largest decade of construction, with about 31% of homes.
Affton is an unincorporated community named for postmaster Johann Aff. The median home in Affton was built in 1958, typical of a postwar St. Louis County inner suburb.
Postwar houses in Affton 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.
Affton has 9,092 homes in the Census Bureau's count and a median year built of 1958. 776 of them (9%) went up before 1940 — 16th of 48 places on this site for pre-1940 share — and 496 (5%) in 2000 or later. The 1950s were the busiest decade, adding 2,820 of today's homes (31%). (St. Louis County as a whole: 10% before 1940.)
The rule of thumb from Missouri's Department of Commerce and Insurance is a useful life of usually about 25 years for a roof. On that yardstick the 8,596 homes in Affton built before 2000 (95%) have outlived at least one roof; 6,836 of them (75%) predate 1970, old enough for two replacements already. Homes from the 2000s (218 in Affton) are reaching their first replacement, while the 278 built since 2010 are mostly still on the roof they were built with. Older houses are where a second layer laid over the first turns up, and that layer is what hides soft decking.
By building type: 7,542 detached houses (83%), 165 attached (2%). 959 homes (11%) sit in two- to nine-unit buildings and 377 (4%) in buildings of ten units or more, whose roofs are normally an owner's or a board's call rather than a resident's. 81% of occupied homes are owner-occupied, 19% rented. Read together, those figures point toward full tear-offs on houses past two roof lives.
| Built | Homes | Share | |
|---|---|---|---|
| Before 1940 | 776 | 9% | |
| 1940s | 1,377 | 15% | |
| 1950s | 2,820 | 31% | |
| 1960s | 1,863 | 20% | |
| 1970s | 733 | 8% | |
| 1980s | 439 | 5% | |
| 1990s | 588 | 6% | |
| 2000s | 218 | 2% | |
| 2010s | 251 | 3% | |
| 2020 or later | 27 | 0% |
Census ACS 2020–2024, tables B25034, B25035, B25024 and B25003: 9,092 homes, 8,695 occupied. Survey estimates.
From 2016 through 2025, NOAA’s Storm Prediction Center recorded 43 reports of hail of 1 inch or more within 5 miles of Affton’s center, spread over 13 storm days. 5 of them were 1.75 inches or larger. The largest, 2 inches, came on May 19, 2025, about 4.5 miles northwest of the center. A report needs someone to see the hail and send it in, so the count is a floor, not a full tally.
| Latest reports | Size | From center |
|---|---|---|
| May 19, 2025 | 1.25 inches | 3.9 mi NW |
| May 19, 2025 | 2 inches | 4.5 mi NW |
| March 14, 2025 | 1 inch | 4.5 mi NW |
| March 14, 2025 | 1 inch | 4.6 mi SE |
| March 14, 2025 | 1 inch | 4.6 mi SE |
Hail damage rarely shows from the ground; a storm inspection photographs each slope so you know either way.
Affton is unincorporated, so St. Louis County Public Works sets the rule. Its re-roofing checklist says no building permit is needed for a like-for-like replacement of asphalt shingles on a roof sloped 4:12 or steeper, unless the job changes something: a permit is required when the slope is under 4:12, when more than 25% of the roof sheathing must be replaced, when the new covering is a different material, or when old board sheathing has to be replaced with structural panels. Work that needs no permit still has to meet the county's re-roofing code.
Affton enforces the 2015 IRC. In Affton the county's code applies: its re-roofing checklist lists the 2015 International Residential Code, adopted by Ordinance 27,654.
The published number is 314-615-5184. Affton 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. Louis County:
| City | Re-roof permit | Code | Median built |
|---|---|---|---|
| Affton | Conditional | 2015 IRC | 1958 |
| Ballwin | Yes | 2015 I-Codes (2024 I-Codes proposed for 2026) | 1976 |
| Brentwood | Not published | 2024 IRC | 1956 |
| Chesterfield | Not published | 2015 IBC / 2015 IRC | 1982 |
| Clayton | Not published | 2021 IRC | 1954 |
| Creve Coeur | Not published | 2009 IRC | 1980 |
| Des Peres | Not published | 2018 I-Codes | 1976 |
All 21 St. Louis County cities side by side →
Affton is unincorporated, so St. Louis County Public Works sets the rule. Its re-roofing checklist says no building permit is needed for a like-for-like replacement of asphalt shingles on a roof sloped 4:12 or steeper, unless the job changes something: a permit is required when the slope is under 4:12, when more than 25% of the roof sheathing must be replaced, when the new covering is a different material, or when old board sheathing has to be replaced with structural panels. Work that needs no permit still has to meet the county's re-roofing code.
Affton enforces the 2015 IRC. In Affton the county's code applies: its re-roofing checklist lists the 2015 International Residential Code, adopted by Ordinance 27,654.
The Census Bureau's 2020–2024 estimates put the median year built at 1958: 9% of Affton's 9,092 homes predate 1940 and 5% were built in 2000 or later. At the usual 25-year roof life, 95% have needed at least one new roof already.
Yes. The most recent report of hail 1 inch or larger within 5 miles of Affton's center was 1.25 inches on May 19, 2025, one of 43 such reports from 2016 through 2025.
Not yet: no completed roof in Affton 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: manchestermo.gov · stlouiscountymo.gov · en.wikipedia.org · censusreporter.org · www.point2homes.com · data.census.gov · www.spc.noaa.gov. Rules and staff change; check with the jurisdiction.
