Miami — Miami-Dade
Waterproofing is the membrane under your shower tile. It keeps water out of the wall, the framing and the unit below. In a Miami condo, a leak through that layer lands on someone else's ceiling. Two things matter most: the membrane type, and a 24-hour flood test before any tile goes down.
Brickell, Downtown Miami, Miami Beach and Aventura are dense with high-rise condo towers. Brickell and Coconut Grove are both neighborhoods of the City of Miami, so a permit for work there comes from the city.
In a tower, the bathroom floor is usually a concrete slab, and that slab is also the ceiling of the unit below. Water that gets past the tile keeps going down, so the membrane protects a neighbor you may never meet.
Many condo associations set work hours, require elevator reservations and ask for sound-control underlayment under hard floors. Ask for those rules before you pick a start date. A schedule that breaks the building rules is harder to fix than one set right at the start. Ask whether the association wants to see the flood test before tile goes in, and get that request in writing.
Florida passed SB 4-D in 2022, after the 2021 Champlain Towers South collapse in Surfside. It requires milestone structural inspections for condominium buildings three stories or taller. Ask the association what it needs to see before work that touches shared structure.
If the job touches a shared wall, the slab or a shared drain stack, tell the association first. Changes to pipes or drains are done by a licensed plumber, and that work is separate from the waterproofing.
ANSI A118.10 is the standard for waterproof membranes set under tile. The TCNA Handbook publishes the tile installation methods used across the U.S.
Sheet membranes such as Schluter-KERDI are laid over the substrate and sealed at their seams. Liquid membranes such as RedGard or Hydro Ban go on in coats. A liquid system needs the curing time the manufacturer gives before anything else goes on top of it.
Corners, joints and fastener points are where water finds a way through, so they get reinforced with preformed pieces or mesh before the main coat goes on.
Niches and benches should slope inward so water runs back into the shower instead of pooling. A shower with no curb step needs a recessed floor or a linear drain to keep water inside the pan.
Before tile goes in, the pan gets a flood test that runs for 24 hours. Plain gypsum drywall does not belong in a wet area, so the walls behind the shower need a board made for damp rooms.
Miami-Dade sits inside the High-Velocity Hurricane Zone. The Florida Building Code applies statewide, and local building departments enforce it.
Atlantic hurricane season runs from June 1 to November 30. If your bathroom project includes a balcony, an outdoor shower or an exterior wall, plan that part of the work around the season and ask what wind rules apply to it.
Humidity stays high here most of the year, and the air near Biscayne Bay and the ocean carries salt. Salt and damp work on exposed metal, grout and caulk, so choose hardware and sealants made for wet rooms.
Interior waterproofing does not change with the weather, but the schedule for anything outside it does. Ask the contractor how a storm would change the schedule, and whether the work can pause safely if one arrives. A question like that is easier to settle before the job starts than in the middle of it.
Before the tile
In a tower, the membrane under the shower is the barrier between your tile and the unit below.
Work hours and elevator bookings are often set by the association, so the schedule has to fit inside them.
Hold water in the pan for 24 hours. In a tower, a drop in level is a leak that can reach the unit below, so it is far easier to find before the tile goes down.
In a tower, access sets part of the price: elevator bookings, work hours and the association's paperwork all take planning. The pan size, the niche count and whether the wet walls are included set the materials. The membrane type matters too. We quote after measuring your bathroom, so the number reflects your room.
In a tower the schedule starts with the association: work hours and the elevator booking come first. Inside those hours the order is fixed. Old surfaces come out, the substrate is ready, the membrane goes on, and the pan is flood-tested for 24 hours before any tile. That wait cannot be shortened.
It depends on the address. Permits are issued by the city for addresses inside city limits and by the county for unincorporated areas. The City of Miami runs its own building department, and Miami Beach, Coral Gables, Doral and Aventura are separate cities with their own. Kendall is unincorporated and goes through Miami-Dade County. Confirm the right office before the work starts.
Many associations set work hours, require elevator reservations and ask for sound-control underlayment under hard floors. Ask for the written rules before you book the elevator or pick a start date. Ask what the association needs to see before work begins, so the request does not stall the job.
"They flood-tested our master shower before any tile went in. Kerdi membrane on the pan and wet walls, then a clean porcelain install. No leaks after a full year of Miami humidity."
Elena R.
Miami, Master Shower Waterproofing
"Condo bathroom in Aventura. AP Stone handled the membrane, flood test, and HOA paperwork without drama. The unit below stayed dry through the whole project."
James T.
Aventura, Condo Wet Walls
"Previous contractor skipped waterproofing. AP Stone tore out the failed walls, installed a proper ANSI membrane, and flood-tested before retile. Should have started with them."
Maria S.
Miami Beach, Shower Rebuild
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