Tub-to-Shower Conversion in Jacksonville: What Changes Behind the Wall

Taking out a tub and putting in a shower is the bathroom job people around Jacksonville ask about most. It looks like a swap. It is closer to building a small new room inside the old one, because nearly everything that makes a shower work sits where the tub never needed anything.

It is plumbing work, so it is permitted work

Three things change in every conversion: the valve, the drain and the floor under the water. The valve and the drain are plumbing, and in the City of Jacksonville, St. Johns, Clay and Nassau alike, changing them needs a plumbing permit, done by a licensed plumbing contractor.

The state’s 2026 permit exemption does not change that. Since July 1, 2026, single-family work valued at $7,500 or less is exempt from building permits only when it includes no plumbing, electrical, structural, mechanical or gas work, and never in a flood hazard area. A conversion always includes plumbing.

If the project is over $5,000, a Notice of Commencement is recorded before the first inspection and a copy is posted at the house. In Jacksonville that is done with the Clerk or at the Building Inspection Division on Hogan Street.

The valve

A tub valve and a shower valve are not the same part. The Florida residential code requires every shower and tub-shower valve to be pressure-balancing, thermostatic or a combination of the two, with a limit stop set so the water cannot come out hotter than 120°F. Many older houses still have two-handle valves that do none of that. In a conversion the valve is replaced, and it is the moment to add a handheld on a slide bar if anyone in the house will want to sit.

The drain

Tubs drain through a smaller pipe than showers. The trade standard is a 1½-inch trap for a tub and a 2-inch trap for a shower, because a shower has no basin to hold water while the drain catches up. On a slab, which is most of the houses around Jacksonville, moving to the larger drain and centering it usually means cutting the concrete floor open where the tub sat. In a 1950s or 1960s house that is also when the old cast iron shows its condition.

The pan

A tub is its own waterproof basin. A shower floor is not, so it needs one underneath. The Florida code allows several kinds of shower liner: a sheet membrane under a mortar bed, a hot-mopped pan, or a bonded waterproofing membrane under the tile. Whatever the method, the liner turns up the walls at least two inches above the threshold, and the floor slopes toward the drain at 2 to 4 percent. Before the tile goes on, the pan is usually plugged and filled for a flood test, and the plumbing inspection looks at it.

Curb or curbless

A curbed shower has a small step at the entry. The code sets the dimensions: the top of the curb sits at least an inch below the shower’s side walls, and the curb is between 2 and 9 inches above the drain.

A curbless shower has no step at all. On a slab that means recessing the concrete inside the shower so the floor can slope, or building up the rest of the bathroom floor to match. It is very doable and it is the better entry for anyone using a walker or a shower chair, but it takes more planning, and the plumbing permit and plan reviewer decide how the pan is built and tested.

The glass

Any glass in a door or panel that faces a tub or shower, with its bottom edge less than 60 inches above the standing surface, is a hazardous location under the code and must be safety glazing, tempered or laminated. Shower doors and panels sold for the purpose already are; the point is to avoid reusing an old window or mirror where it does not belong. Clear glass also shows Jacksonville’s hard water; JEA’s published hardness runs into the high teens and above in much of the county, so a coating or a squeegee is worth planning for.

The fan

Every bathroom exhaust has to vent directly outdoors, not into the attic. A shower produces more steam than a tub, so a conversion is a good time to check where the old fan actually goes. The EPA’s guidance is to keep indoor humidity under 60 percent and run the fan while showering.

What moves the calendar

No two conversions run the same length, and the remodeler sets the schedule. The things that usually decide it here: permit review, what the old drain looks like when the floor comes up, the pan flood test and its inspection, tile curing, and custom glass, which can only be measured after the tile is set.

Before you call

Know which tub it is, hall bath or primary, standard or garden tub; whether it is the only tub in the house; and whether you want a curb or not. Photos of the room help.