Why a carport slab is really about the posts
A carport has a big roof and almost no walls. When hurricane wind gets under that roof it lifts, and the only things holding it down are the anchors at the bottom of each post. The flat slab in between matters for parking; the concrete at the posts matters for keeping the carport in your yard.
- Get the carport maker's drawings with post spacing and anchor details first
- Thicken the slab or add footings where each post lands
- Set anchors to the engineered pattern; don't improvise spacing
- Keep anchors away from slab edges and joints as the design calls for
- Slope the slab so water runs out from under the roof
Tampa wind and carport anchors
Under the 2023 Florida Building Code, Tampa and Hillsborough County design for an ultimate wind speed of roughly 150 to 160 mph, with Exposure C, the higher-pressure category, for sites near Tampa Bay or in open country. Tampa sits in the wind-borne debris region. A carport that meets those numbers does it through its anchorage, which is why the county asks for sealed or approved plans and why those plans, not a generic kit sheet, decide the bolts.
The hurricane wind and anchoring guide goes through exposure categories and uplift in more detail.
Carport permits in Hillsborough County
Hillsborough County names carports specifically in its guide for residential accessory structures over 150 square feet. Expect a scaled site plan with setbacks to every property line, easements and wetlands marked, sealed plans from a Florida architect or engineer or approved DCA plans, and a recorded Notice of Commencement before the first inspection. On a lot in a Special Flood Hazard Area, the flood rules apply too.
Inside Tampa city limits, the City's own process applies; check with the City before you order. The Tampa slab permit guide covers both.
Carport slab sizes and cost
| Carport | Area | Slab at $5.55 to $11.09 per sq ft |
|---|---|---|
| Single, 12x20 | 240 sq ft | $1,332 to $2,662 (computed) |
| Single long, 12x24 | 288 sq ft | $1,598 to $3,194 (computed) |
| Double, 20x20 | 400 sq ft | $2,219 to $4,438 (published) |
| Double long, 20x24 | 480 sq ft | $2,664 to $5,323 (computed) |
Swipe the table sideways to see every column →
projectcosted, Tampa, August 2026. Post footings, engineered anchors and the permit are extra.
No vapor retarder needed
Florida's code exempts carports from the 6-mil vapor retarder under floor slabs, so a carport slab skips that layer unless the plan is to enclose it later.
Walls instead of open sides? See garage slabs. Parking a camper? RV and boat pads.