Roofing permits in St. Louis, City vs. County
Often no, for a like-for-like replacement. In the City of St. Louis, re-roofing with like material and replacing 25% or less of the sheathing usually doesn't need a permit. St. Louis County's guide says the same for like-for-like asphalt shingles on roofs of 4:12 slope or steeper. Here are the details and the exceptions.
| City of St. Louis | St. Louis County (where the County enforces the code) | |
|---|---|---|
| Like-for-like re-roof | Usually no permit, if 25% or less of the sheathing is replaced (Source: City of St. Louis) | No permit for like-for-like asphalt shingles on roofs of 4:12 or steeper (Source: St. Louis County) |
| More than 25% new sheathing | Permit needed (Source: City of St. Louis) | Permit needed (Source: St. Louis County) |
| Changing materials (e.g. shingles to metal) | Permit needed: "an entire new roof, when roof work is not replacement of like material" (Source: City of St. Louis) | Permit needed (Source: St. Louis County) |
| Low-slope roof (under 4:12) | Follow the like-material rule above | Permit needed (Source: St. Louis County) |
| Gutters and downspouts | No permit (Source: City of St. Louis) | Ask your municipality |
"No permit" doesn't mean "no rules." The work still has to meet the building code (Source: St. Louis County).
City of St. Louis: the 25% sheathing rule
The City's Building Division lists the residential work that does and doesn't need a permit (Source: City of St. Louis):
- No permit usually needed for "roof replacement when done with like material and replacement of 25% or less of the roof sheathing." The same list exempts repairing or replacing gutters and downspouts, and pre-finished aluminum, steel or vinyl on soffits, fascia and overhangs.
- Permit needed for "an entire new roof, when roof work is not replacement of like material," and "when more than 25% of the roof sheathing is removed and replaced."
What that means in practice: a shingle-for-shingle replacement on a sound deck usually needs no permit. If the roofer finds a lot of rotten decking once the old roof is off, crossing 25% means a permit. Ask your roofer before signing who will pull it if that happens.
Questions go to the City's Permits Section: stlcitypermits@stlouis-mo.gov or (314) 622-3313 (Source: City of St. Louis). Homes in historic districts may have extra review for exterior changes, so check with the City before changing roofing materials or colors.
St. Louis County: the 4:12 slope rule
St. Louis County's residential re-roofing guide says a building permit is not required for like-for-like replacement of asphalt shingles on roofs with a 4:12 or greater slope (4 inches of rise per 12 inches of run). It is required when (Source: St. Louis County):
- the roof slope is less than 4:12,
- more than 25% of the roof sheathing needs replacing, or
- the roofing material changes.
Who that applies to. The County enforces its code in unincorporated areas (such as Affton, Oakville, Mehlville and Lemay) and in municipalities that contract with the County for code enforcement. Many County municipalities run their own building departments and permit rules. Check with your city hall. Areas and who issues permits
The County's guide references an older code edition (the 2015 IRC), so confirm with the County or your municipality before you rely on it.
Tear-off and the two-layer limit
- A roof replacement removes the existing layers down to the deck (Source: IRC R908).
- A recover (new shingles over old) isn't allowed where there are already two or more layers, where the existing roof is water-soaked or deteriorated, or over slate or tile (Source: IRC R908).
Local codes adopt and amend the model code, so ask your roofer how many layers are on your house and whether yours needs a full tear-off. Older St. Louis homes often have two.
Licensing: it's local
Contractor licensing in the St. Louis area is handled locally, so it depends on where you live.
- City of St. Louis: construction contractors need the City's Construction Industry Contractor Graduated Business License, which requires proof of workers' compensation coverage or an exemption affidavit. Questions: the License Collector, lco@stlouis-mo.gov or 314-622-4528 (Source: City of St. Louis).
- St. Louis County and its municipalities: requirements vary. Ask your city hall, or the County for unincorporated areas.
We only refer local roofing contractors licensed where your city requires it. Before you hire, ask any roofer which local licenses they hold, and ask for a certificate of liability insurance.
Questions to ask your roofer about permits
- Does my job need a permit where I live? If so, who pulls it, and is it in the price?
- How many layers are coming off?
- What happens if more than 25% of the decking is bad?
- Am I changing materials, such as going from shingles to metal, or to a membrane on a low-slope section?
Sources
Last reviewed October 22, 2026.
- When a residential building permit is needed, City of St. Louis Building Division. Accessed October 22, 2026.
- Residential re-roofing checklist and guide for asphalt shingles, St. Louis County Department of Transportation and Public Works. Accessed October 22, 2026.
- Permits (Building Division), City of St. Louis Building Division. Accessed October 22, 2026.
- International Residential Code, Section R908 Reroofing (model code), International Code Council. Accessed October 22, 2026.
- Apply for a Construction - Contracting Business License (Graduated Business License), City of St. Louis License Collector. Accessed October 22, 2026.