Interpretation #8752
Published April 28, 2023
Original Request
- Code Version
- 2021
- Code
- BUILDING
- Code Description
- Chapter
- Section
- Topic
- Use of Stem Walls within a Coastal A Zone
Question
The use of stem walls within a CAZ is allowed per ASCE 24-14. A stem wall is defined as a backfilled wall supporting a floor or flooring system. Can a stem wall be used to support a garage floor within the CAZ?
Answer Published 04/28/2023 at 10:35 AM
Yes, backfilled stem walls are permitted for any structure in Coastal A Zones (seaward of Limit of Moderate Wave Action delineated on FIRM). Detached and attached garages may be constructed on backfilled stem walls in CAZ. It appears the question is about an attached garage (to the side of a building, not underneath). The floor of an attached garage is NOT the “lowest floor” of the elevated building. When the floor of an attached garage is below the elevation required for the building, the garage must comply with the requirements of FBCB/ASCE 24 Section 4.6, or FBCR R322.3.5 for enclosures and the use limitation of both (R322.3.6.
When considering detached garages, please be aware that FEMA issued a policy to permit certain non-elevated detached accessory structures, subject to size limits and wet floodproofing provisions. Many Florida communities modified their regulations to specify those requirements, but all communities should comply with the FEMA guidance. See FDEM OFM guidance by visiting https://www.floridadisaster.org/dem/mitigation/floodplain/community-resources/ and look under “Guidance, Ordinance Amendments, FBC Amendments, and Sample Forms.
When considering detached garages, please be aware that FEMA issued a policy to permit certain non-elevated detached accessory structures, subject to size limits and wet floodproofing provisions. Many Florida communities modified their regulations to specify those requirements, but all communities should comply with the FEMA guidance. See FDEM OFM guidance by visiting https://www.floridadisaster.org/dem/mitigation/floodplain/community-resources/ and look under “Guidance, Ordinance Amendments, FBC Amendments, and Sample Forms.
Commentary
None.