Slab Leak Water Damage — Florida

The most common slab leak indicators in Florida homes: (1) A warm or hot spot on the floor — particularly noticeable with tile or hardwood flooring — indicates a hot water supply line failure under the slab; (2) LVP (luxury vinyl plank) flooring warping, cupping, or showing seam gaps in a specific area without a surface water source; (3) Unexplained wet spot in carpet concentrated in one area; (4) Water meter running with all fixtures off — shut off all fixtures and check if the meter dial is still moving; (5) Unexplained increase in water bill; (6) Sound of running water when all fixtures are off. Electronic leak detection ($300–$800) can locate the precise failure point under the slab within a few inches — required before any slab cutting.

Two primary causes dominate Florida slab leaks. Aging copper supply lines: Florida's 1960s–1980s CBS slab-on-grade homes have copper supply lines that are now 45–65 years old. Florida's groundwater chemistry — high sulfate and chloride content in Central and South Florida's limestone aquifer — corrodes copper pipe from the exterior. Thermal expansion stress from Florida's heat cycling fatigues joints and fittings over decades. CPVC pipe failures: CPVC was the dominant supply material in Florida construction from 2003–2015. CPVC becomes brittle as it ages and is now in its 15–25 year brittleness window for properties in that construction era. CPVC slab failures produce the same sudden rupture as copper failures but are from brittleness rather than corrosion.

Three repair methods are available for Florida slab leaks: (1) Slab cutting — the most direct method: a concrete saw cuts an access hole to the failed pipe section, the section is repaired or replaced, and the concrete is restored. Cost: $3,500–$8,000+ including concrete restoration. Disrupts flooring permanently in the access zone. (2) Pipe rerouting (repiping) — new supply lines are run through walls and ceiling above the slab, bypassing the under-slab pipe entirely. The failed pipe is abandoned in place. Cost: $2,500–$6,000. Avoids slab disruption. PEX is the standard replacement material — PEX is not embedded in slabs and runs through walls. (3) Epoxy pipe lining — epoxy resin is injected inside the existing pipe to seal the failure point from the interior. Cost: $2,000–$4,000. Only applicable to specific pipe types in specific conditions; not always an option.

Water from a slab leak migrates under LVP (luxury vinyl plank) flooring through the interlocking joint system — typically 5–15 feet in any direction from the leak point, sometimes further in open-plan areas. The LVP surface is water-resistant, so there is no visible indication at the surface until the planks begin warping, cupping, or showing seam gaps — which may not be noticeable for 24–48 hours after onset. Thermal imaging of the slab surface maps the full wet zone under the LVP before any flooring is removed. In Florida's open-plan layouts, a slab leak under a kitchen can migrate under continuous LVP into the dining and living area — requiring full connected-run replacement under FL Statute 627.7011's matching doctrine if the pattern is discontinued.

Yes — mold growth under LVP on a wet concrete slab begins within 48–72 hours in Florida's ambient humidity. The concrete slab surface, the moisture barrier membrane below the LVP, and the LVP backing material are all substrates for mold growth in the trapped, warm, humid environment beneath the flooring. Mold colonies are often discovered at LVP removal during restoration — not before. This is why the restoration clock matters: a slab leak discovered within 24–48 hours may avoid significant mold growth; one running for 72 hours or more in a vacant Florida home will typically have mold already established on the slab surface before flooring removal. Mold treatment of the slab surface = MRSR-licensed scope (Citizens $10k sublimit); LVP removal and replacement = Coverage A structural scope (no sublimit).