In Union, the 2021 IRC is in force and 8% of the 5,399 homes went up before 1940. We replace and repair roofs here and inspect after hail, starting with a free, photographed inspection.
Union runs to about 9.03 square miles and roughly 12,348 people. It sits about 50 miles southwest of downtown St. Louis. The community dates back to 1826. We cover ZIP code 63084.
No completed roof in Union is logged in our job records yet.
Union grew fastest from 2000 to 2010, when its population rose 31.5%, and its housing skews toward 1990s-2000s suburban construction.
Union is the Franklin County seat, designated in 1827, and sits on the Bourbeuse River. Its population grew from 402 in 1880 to 12,348 by 2020.
From this stretch of building, houses in Union sit on plywood or OSB, were first roofed in three-tab shingles, and are mostly on their second roof now. Trouble tends to be at the penetrations rather than across the field: the rubber collar on a pipe boot splits years before the shingles give out, and it is the leak we trace most often. Ridge vents were hit and miss in these decades, and OSB that stays damp for a season softens in a way plywood does not, something you feel underfoot rather than see from the yard.
By the Census Bureau's estimate there are 5,399 homes in Union, with a median year built of 1996. 432 of them (8%) went up before 1940 — 19th of 48 places on this site for pre-1940 share — and 2,384 (44%) in 2000 or later. The 2000s were the busiest decade, adding 1,379 of today's homes (26%). (Franklin County as a whole: 10% before 1940.)
About 25 years is the usual working life of a roof, by the figure Missouri's insurance department publishes. On that yardstick the 3,015 homes in Union built before 2000 (56%) have outlived at least one roof; 1,336 of them (25%) predate 1970, old enough for two replacements already. First replacements are arriving on the 1,379 homes built in the 2000s, while the 1,005 built since 2010 are mostly still on the roof they were built with. At that age it pays to know whether the last roof was torn off or laid over the one before it, because a second layer hides the deck.
Detached single-family houses make up 64% (3,437); attached houses and townhouses 8% (455). 870 homes (16%) sit in two- to nine-unit buildings and 223 (4%) in buildings of ten units or more, where the roof is usually a landlord's or an association's decision. The count also takes in 414 mobile homes, which are a different kind of roof job. Owners live in 61% of the 4,990 occupied homes. Read together, those figures point toward 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 | 432 | 8% | |
| 1940s | 185 | 3% | |
| 1950s | 318 | 6% | |
| 1960s | 401 | 7% | |
| 1970s | 314 | 6% | |
| 1980s | 517 | 10% | |
| 1990s | 848 | 16% | |
| 2000s | 1,379 | 26% | |
| 2010s | 888 | 16% | |
| 2020 or later | 117 | 2% |
Census ACS 2020–2024, tables B25034, B25035, B25024 and B25003: 5,399 homes, 4,990 occupied. Survey estimates.
NOAA’s Storm Prediction Center logged 3 reports of hail 1 inch or larger within 5 miles of Union’s center from 2016 through 2025, on 3 different days. 2 of them were 1.75 inches or larger. The largest, 3 inches, came on April 15, 2023, about 0.9 miles north of the center. The most recent was 1.75 inches on March 14, 2025. Counts follow people as much as storms, since every report is a spotter’s or a resident’s.
| Latest reports | Size | From center |
|---|---|---|
| March 14, 2025 | 1.75 inches | 1.9 mi SE |
| April 15, 2023 | 3 inches | 0.9 mi N |
| May 11, 2016 | 1 inch | 0.9 mi N |
Hail damage rarely shows from the ground; a storm inspection photographs each slope so you know either way.
The city says building permits are required for 'all residential and commercial construction and remodeling projects within the City' but does not name re-roofing. The permit application asks for truss plans 'if roofing is involved,' which suggests roof work is covered.
Union enforces the 2021 IRC. The city uses the 2021 ICC codes for Building, Residential, Existing Building, Plumbing, Mechanical, Fuel Gas, Property Maintenance and Energy Conservation, plus the 2020 NEC as amended. Details are in Chapter 500 of the city code, and the city's code page was last updated in February 2024.
The published number is 636-583-1805. Union 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.
Wind 115 mph (ultimate) and ground snow 20 psf, the same across the metro; see the roofing code guide for what they govern.
Also in Franklin County:
| City | Re-roof permit | Code | Median built |
|---|---|---|---|
| Union | Not published | 2021 IRC | 1996 |
| Pacific | Not published | Not published | 1985 |
| Washington | Not published | 2021 IRC | 1978 |
All 3 Franklin County cities side by side →
The city says building permits are required for 'all residential and commercial construction and remodeling projects within the City' but does not name re-roofing. The permit application asks for truss plans 'if roofing is involved,' which suggests roof work is covered.
Union enforces the 2021 IRC. The city uses the 2021 ICC codes for Building, Residential, Existing Building, Plumbing, Mechanical, Fuel Gas, Property Maintenance and Energy Conservation, plus the 2020 NEC as amended. Details are in Chapter 500 of the city code, and the city's code page was last updated in February 2024.
Median year built 1996, by the Census Bureau's 2020–2024 estimates. Of 5,399 homes, 3,015 were built before 2000 and 432 before 1940, so most roofs in Union are not the first one the house has had.
The last report near Union of hail 1 inch or bigger came on March 14, 2025; NOAA's records hold 3 of them within 5 miles since 2016.
Not yet: no completed roof in Union 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.unionmissouri.gov · www.unionmissouri.gov · ecode360.com · cms4files.revize.com · en.wikipedia.org · www.city-data.com · data.census.gov · www.spc.noaa.gov. Rules and staff change; check with the jurisdiction.
