When docks, lifts, decks, or patios settle near the water in St. Petersburg, the lasting fix is to transfer their weight to firm soil with helical piers, or to fill the voids that formed beneath them.
866-398-9323Licensed seawall specialists — FL · GA · SC
Seawall Repairs by Solid Foundations provides marine foundation repair in St. Petersburg, FL for waterfront homeowners, HOAs, and marinas. Typical projects include helical piers under sagging docks in Shore Acres, re-leveling boat lifts on Snell Isle, and lifting pool decks that dropped behind Coquina Key seawalls. Call 866-398-9323 or use the quote form to book a free on-site inspection.
Nearly all of these come from soft ground or from soil washing out through the wall.
Much of it was made by dredges. Snell Isle started out as a small spoil island that was often submerged at high tide, and Shore Acres was filled using dredges from the Gandy project (Northeast Journal). Beneath lots like these you'll often find:
Flooding adds to it. When Helene put these neighborhoods under bay water in 2024, the fill beneath slabs and dock landings was soaked through, then left to settle unevenly as it drained.
Steel shafts with helical plates are screwed down until installation torque shows they've reached load-bearing soil. We bracket them to the structure and lift it toward level. See helical pier installation.
Voids under decks and patios are filled with polyurethane foam, which firms the soil and can raise the slab without demolition.
Rotted, bored, or storm-struck pilings can be wrapped, jacketed, or backed up with new support.
If fill is leaving through the seawall, we pair the work with bulkhead repair in St. Petersburg so settlement doesn't return.
If a foundation repair turns into rebuilding a deck or patio, the City of St. Petersburg's encroachment rules come into play:
| Structure near the seawall | Minimum distance from the seawall |
|---|---|
| Uncovered deck or patio up to 12 in high | 5 ft |
| Uncovered deck or patio 12–30 in high | 8 ft |
| Covered patio, pergola, or screen enclosure | 10 ft |
| Waterfront retaining wall | No taller than the top of the existing seawall |
Source: City of St. Petersburg allowable encroachments. The city notes that state and federal rules may be stricter. Repairing in the existing footprint usually keeps things simple.
Marine foundation repair in St. Petersburg typically costs $700–$2,000 per helical pier and $8–$25 per board foot for void fill. Most residential marine foundation repairs run $5,000–$25,000, depending on pier count, depth to firm soil, and access.
For full dock rebuilds, see marine construction in St. Petersburg. We also handle this work in Tampa and Clearwater, and our St. Pete seawall repair page lists everything else we do here.
Usually. If the pilings are sound but settled, we add support and re-level the lift. Damaged pilings can be replaced individually.
Under the city's encroachment rules, an uncovered patio up to 12 inches high must stay at least 5 feet from the seawall, and taller or covered structures farther back.
The fill under it is settling or washing out through the wall. We evaluate the wall and the soil together so the fix lasts.
Often, yes. Foam injection or helical piers can lift many slabs back toward their original level.
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866-398-9323