If you Google this question you will find contrasting answers; from "2 days" to "4-6 weeks". Having done many high end showers, I'll try to help clear up any confusion. First, for those who are expecting a 1 or 2 day tile shower installation, I recommend the following link:Bathfitters
For a custom, warranty-able tile shower, there are many things to consider that will effect the duration of the job:
1) Demolition (typically, most issues are encountered at this point)
2) Carpentry (typically, there will be changes in the layout)
3) Plumbing (there will be necessary changes made to the existing plumbing, even if it's just the drain connection)
4) Trade stacking (scheduling 2 or more trades in the same room only causes distractions, accidents, parking issues, utilities usage issues, dust contamination issues, general foot traffic issues, materials storage issues and can add SIGNIFICANT DELAYS TO YOUR PROJECT)
5) Shower pan (we do not tile over existing shower pans as they are incompatable with quality, warranty-able shower systems, every custom shower comes with a new shower pan)
6) Sub-strate preparation and/or waterproofing (the sub-strate is the waterproofing if using Kerdi-Board, Durock and Hardi Board take longer to install because of new county ordinances regarding the cutting of toxic materials)
7) Shower build (benches, knee walls, windows, etc.)
8) Accents (extrusions and trim/edge protection, niches, shelves, mosaics, inserts/bands, etc.)
9) Type of tile (glass and natural stone are harder to work with, porcelain is harder to cut, large format must have a perfectly level substrate and larger capacity cutting equipment, etc.)
10) Tile patterns (diagonal, herringbone, etc.)
11) Smaller grout lines (smaller grout lines show all flaws and much more attention must be paid to detail when setting tiles and when grouting. Preventing lippage with 1/16th'' grout lines requires the installer use a quality lippage system and that adds some extra time to setting each tile and believe this - no tiles are exactly the same size, though some maybe closer than others)
12) Tiled ceilings (tiling a ceiling, especially if the installer is using a lippage system, takes longer than wall tiles)
13) Windows (whether installing a glass block window or just tiling around a window, there will be inherent difficulties in compensating for "out of square" measurements between the exterior and the intererior sub-strates)
14) Shower doors and glass enclosures (if the tile installer will also be installing your shower doors you can expect that it will take several hours to do it right, cutting the metal to fit perfectly, leveling the header, etc.. If you're having the glass company install an enclosure, you will be subject to their scheduling and the tile setter isn't going to be "camped out" in your yard waiting for them to finish. Custom glass enclosures could take as long as 9 weeks from ordering to installing and should be one of the first things you do)
15) Drywall and plaster repairs, sealing tile or grout, caulking, detailing and touch ups ((just because the job looks finished to you doesn't mean that the shower is ready to turn over, a good tile installer may spend an entire day or more dealing with finish details, even grout haze removal can take some time)
16) 24 hour water test (a shower base must be tested for its ability to hold water for at least 24 hours and then tested for adequate drainage with water running at full capacity to be considered warranty-able)
17) Inspections (if the job is "permitted" and is under the control of a builder or general contractor, there will likely be several unnecessary inspections scheduled as the GC gets paid everytime an inspection is scheduled)
18) Fixtures, handrails (depending on the number of fixtures, the type of fixtures and the type of tiles - with glass, in particular, it can take a day or more to install the fixtures correctly and without cracking the tiles)
19) Scheduled payments and draws (if there are hold ups on any payments during the job, you may likely cause hardship for an installer, as most of the time, the installer pays for supplies, fuel, human resources, etc. for your job, out of their own pocket, i.e. it can be very easy for a client to cripple an installers performance by not funding the project appropriately)
20) Staging (it is your responsibility to designate an area for the installer to set up equipment for the job. If the area you designate is distanced from the destination, has no reasonable access to water and power, floods when it rains, requires stringent cleaning at the end of every day or doesn't provide reasonably close parking, you can expect significant delays. This also applies to materials storage)
21) Change orders (if a change in the original design is submitted that requires ordering additional materials, you will be subject to however long it takes for the additional materials to ship)
In summary: Any truly custom tile shower, 3 x 5 or larger that doesn't take 3 weeks or longer, is - NOT WARRANTY-ABLE FOR MORE THAN 1 YEAR, NOT IN ANY WAY COMPLEX, NOT EVEN CLOSE TO PRECISION WORK and DOES NOT HAVE 80% OR MORE CONTACT
This completion projection is based on actual hours worked on an average project and divided by 8 hour days and 5 day work weeks. In all cases, we are working on your project for several hours per project - off site - developing, aquisitioning and delivering orders for your project. In some cases, we are rendering drawings or doing "mock-ups" of a particular construction objective related to your project. These hours, sometimes many, are not included in this calculation, but probably should be.
Keep in mind that; we gain absolutely nothing by prolonging an installation.
Perfection is the child of time.
If you have not planned, in advance, for a precision, waterproofed, custom tile installation or don't have the patience for the installer that wants to "do it right" - we are not the company for you. Please continue your search. There are many jack-leg installers out there with open schedules and underwhelming portfolios. You will, undoubtedly, find the right one for you, eventually.