Converting a tub to a walk-in shower is the most requested bathroom project we do, and it is also the one where the gap between a good job and a bad one is most completely hidden from view.
When it is finished, two showers can look identical. One will still be watertight in twenty years. The other will be rotting the framing behind the tile within five, and you will not know until the ceiling below it stains.
Here is what actually happens between demolition and tile, and what to ask about before you hire anyone.
Step one: demolition and honest assessment
The tub comes out, the surround comes off, and the wall cavity is opened. This is the moment where a project either proceeds as quoted or gets an honest revision, because it is the first time anyone can actually see the framing, the subfloor, and whatever the previous installation was doing.
What we find here is frequently instructive. Drywall behind an old tub surround instead of cement board. Framing that has darkened from years of slow leakage. Subfloor soft around the drain. Studs that are out of plumb enough that a large-format tile will not sit flat against them.
A contractor who quotes a conversion without a contingency for what is behind the wall is either very lucky or planning to have an uncomfortable conversation later. We flag likely issues during the walkthrough so the possibility is on the table before demo starts.
Step two: framing and the new footprint
A standard alcove tub is 60 inches long and about 30 deep. A shower built in that same footprint gains usable space because you are no longer stepping over a 15-inch tub wall, but the opening usually needs reframing — the studs at the tub end were sized for a tub deck, not a shower curb and glass panel.
This is also where accessibility decisions get made. A curbless entry requires the subfloor to be recessed between the joists or the surrounding floor built up, so the slope to the drain works without a threshold. It is very achievable on many homes and impossible on some, and the only way to know is to look at the floor structure.
Benches and niches get framed at this stage too. Both need to be built into the wall structure and waterproofed as part of the enclosure — adding them later is not a real option.
Step three: the pan, which is where showers are won or lost
Water has to reach the drain. That sounds obvious, and it is the single most commonly botched element in shower construction.
The floor of the shower needs a consistent slope of about a quarter inch per foot toward the drain — no flat spots, no reverse pitch, no low corners where water pools. That slope is created in a mortar bed, floated and screeded by hand, and it is genuinely skilled work.
You can also use a pre-sloped foam pan system, which is faster and produces excellent, consistent results. Either approach is legitimate. What is not legitimate is tiling directly over a flat floor and hoping grout keeps water out.
Step four: waterproofing — the part nobody sees
This is the answer to the question of why one shower lasts and another does not. Tile is not waterproof. Grout is not waterproof. Water gets through both, continuously, every time the shower is used. Something behind them has to stop it.
That something is a waterproof membrane — a sheet or liquid-applied system bonded over cement backer board across the entire wet enclosure, with every seam, corner, and penetration lapped and sealed. Done correctly, the water that passes through the grout hits the membrane and drains back out through weep holes at the drain.
The failure mode is straightforward: no membrane, or a membrane that was not sealed at the corners and the mixing valve penetration. Water passes the tile, reaches drywall or bare framing, and starts a slow rot that takes years to become visible.
- Cement backer board on all wet walls — never drywall, never greenboard
- A bonded waterproof membrane over the board, lapped at every seam
- Corners, curbs, and the pan-to-wall transition sealed with dedicated corner pieces
- The mixing valve and shower arm penetrations sealed individually
- A flood test on the pan before any tile goes down
Step five: tile, grout, and glass
With the enclosure watertight, tile is layout work. The field gets centered so cuts land symmetrically, the niche is aligned to the tile grid rather than to the studs, and the wall tile is set plumb regardless of what the framing is doing.
Grout goes in after the mortar cures. Every change of plane — the inside corners, where wall meets pan, where the curb meets the floor — gets silicone rather than grout, because those joints move and grout cracks when it does.
Glass is measured against the finished tile, never against the rough opening. That is why the glass typically arrives about a week after tile is complete, and it is exactly why the reveals are tight on a professional job and uneven on a rushed one.
Timeline and living through it
A typical tub-to-shower conversion runs five to nine working days for the construction, plus roughly a week of lead time on the glass. The bathroom is unusable during construction and usable — minus the glass door — for the week in between.
You do not need to move out as long as there is a second bathroom. We seal the doorway against dust, protect the adjoining floors, and clean the site at the end of each day.
The largest schedule variables are what demolition uncovers and how intricate the tile selection is. Mosaic shower floors and patterned wall tile both take meaningfully longer to set than large-format porcelain.
Questions worth asking any contractor
If you take one thing from this article, make it this list. The answers tell you almost everything about how the shower will be built.
- What waterproofing system will you use, and will the seams and corners be sealed?
- Will you flood-test the pan before tiling?
- Is the pan being floated in mortar or built with a pre-sloped system?
- What is going on the walls — cement board, foam board, or drywall?
- Will the corners and the pan-to-wall joint be siliconed or grouted?
- Will the glass be measured after the tile is finished?
Talk to us before you commit
Flooring GT builds walk-in showers and tub-to-shower conversions across Oklahoma City, Edmond, Norman, Moore, Midwest City, Mustang, Bethany, Choctaw, and the wider metro. Every project starts with a free walkthrough and a written scope that spells out the waterproofing system by name, not in vague terms.
If you are gathering quotes, use the questions above on all of them. The answers will tell you more than the price will. Call (405) 900-2891 to arrange a walkthrough — we are open seven days a week.
