St. Louis roofs sit on the western edge of the Midwestern severe-weather corridor, and Missouri collects a bit of everything the middle of the country produces: spring hail from the Great Plains storm track, straight-line thunderstorm gusts across the Mississippi Valley, humid summers that promote algae growth, and freeze-thaw winters that work water into any weakness on the roof deck. St. Louis City and County homeowners collect the consequences on a schedule that varies year to year but never disappears.
Hail is the everyday problem. St. Louis averages several damaging hail events per year across the metro, and hailstones over an inch produce insurance claims routinely. Small hail is the sneakier version, chipping granules from shingles across multiple seasons and shortening a 30-year architectural shingle to closer to 15 without ever triggering an obvious claim.
Class 4 impact-rated shingles are worth pricing
Because Missouri hail loss frequency is high, most St. Louis-area carriers offer a wind-and-hail premium discount for a UL 2218 Class 4 (impact-resistant) shingle. The material premium over a standard architectural shingle is modest; the deductible savings on the next hail event typically recovers it. Ask any prospective contractor whether the quote is Class 4 rated and whether they will file the impact-resistant certification form with your insurer.
Historic brick homes need contractors who understand them
St. Louis has a large stock of older brick housing across Soulard, Lafayette Square, the Central West End, and the South City neighbourhoods. Many of these homes have steep-pitched roofs with complex valleys, dormers, and chimney intersections that require framing and flashing knowledge not every crew has. A written scope should specify how each valley, dormer, and chimney will be handled — not just the field material.
Freeze-thaw compresses roof life
Missouri winters cycle through the freezing point repeatedly, and any lifted shingle or exposed nail head takes on water, freezes, and pries open further with each pass. Ice-and-water barrier at eaves is code-required under Missouri’s adopted IRC and should extend inward past the exterior wall line — not just to the drip edge.
Algae-resistant shingles for humid summers
The dark streaking on north-facing slopes across St. Louis is Gloeocapsa magma. Algae-resistant (AR) architectural shingles cost negligibly more and prevent the streaking that standard shingles will develop within three to five years in Missouri humidity.
St. Louis City and County permits
The City of St. Louis Building Division and St. Louis County each issue re-roof permits for their respective jurisdictions. Confirm which office your roofer will file with and that the permit is a line item on the written quote.