These are the two quotes most families end up holding, and they are for genuinely different work. One is a surface. One is a rebuild.
What each one actually is
A liner or one-day conversion fits new material over or into the existing structure. Bath Fitter, for example, describe their process as installing a custom-made acrylic liner over the existing fixture without demolition, typically in a single day.
A full conversion removes the tub, opens the walls, and rebuilds the enclosure — including what is behind the tile.
| One-day liner | Full conversion | |
|---|---|---|
| Time on site | One day | Four days low-step, seven curbless |
| Walls opened | No | Yes |
| Blocking behind the tile | Not possible | Yes, all three wet walls |
| Curbless entry | No | Yes, where the floor structure allows |
| Door width or layout changed | No | Yes, where framing allows |
| What is behind the old surface | Stays there | Seen and dealt with |
| Typical cost | Lower | $16,500 to $26,500 |
The difference that matters most
Blocking.
If the walls are not opened, solid blocking cannot be added behind them. Bars have to go into whatever studs happen to be there, or into hollow-wall fasteners through the new surface. That can be done properly — engineered fasteners rated to 800 lb are an accepted alternative — but it constrains where a bar can go to where the ergonomics need it rather than where the framing allows.
In a full conversion, continuous blocking goes across three stud bays at roughly thirty-four inches. A bar can be placed anywhere on that wall, today or in five years, without opening finished tile.
When the one-day option is genuinely the better choice
And we mean genuinely. If any of these describe you, call a liner specialist rather than us.
One bathroom and four days is impossible. A day of disruption versus four is not a close call when there is nowhere else to wash.
The problem is the tub wall and the slippery surface, nothing structural. If she is steady on her feet and the need is not expected to increase, you do not need the floor rebuilt.
Budget is the binding constraint. Doing something now beats doing something perfect never.
When it is not
A walker or wheelchair is involved, or is coming. An occupational therapist has written a specification with clearances in it. The door, the layout or the floor structure needs to change. Or you are solving for the next ten years rather than the next one.
The honest summary
Neither company is lying to you when the numbers differ by fifteen thousand dollars. They are quoting different jobs. The question is not who is cheapest — it is which kind of work her bathroom actually needs.
Five kinds of company do this work
The full comparison covers liner specialists, walk-in tub companies, tub cutout retrofitters, general contractors and accessibility specialists — and says which situations point away from us.