The Plumbing Wizard I've seen the floor installed first one time. It's way more common to install the tub first. For one thing, the floor may not even be level. With an out of level floor, the tub can be shimmed, and the flooring hides the gap.
Protection against Damaged Floors
However, if you have the flooring installed first, it can easily get scratched, cracked, or even completely ruined by trying to place a heavy object such as a bathtub on it, so it's often best and more convenient to place the tub first and add the new flooring afterward.
Bath always installed first, then tiles set out to take into consideration floor/ceiling, bath/windows or any other feature necessary to overcome. Obviously, you could do the bulk of the tiling without the bath in, then tile down to bath once fitted...
It is generally recommended to tile the shower floor first and then move on to the walls. This is because the slope of the shower floor needs to be built first to ensure proper drainage, and then the walls can be tiled on top of the floor tiles.
Tile can end at tub or at the wall (but then will need to run down the wall in front of the tub at the bottom). I would do at wall/running down to better prevent drywall from getting wet if it runs down the side of the tub where it meets the wall.
BEST SEALANTS FOR CAULKING BATHTUBS
Loctite Polyseamseal Tub & Tile Adhesive Caulk has been specifically formulated to create a long-lasting, flexible seal that is resistant to mold and mildew. It works on both fiberglass and ceramic surfaces as a two-in-one product, making it highly versatile.
Plan to extend the tile 2 or 3 in. beyond the tub and leave at least a half tile along the wall if possible. Don't stop tile even with the end of the tub. This leaves the walls along the front of the tub vulnerable to water damage and doesn't look as finished as tile that extends to the floor.
Why You Should Tile the Wall First. It may be delicate to create a suspended wall tile effect if you tile the walls first. On the flip side, tiling the walls first will help you dodge the mishaps and messes associated with tile and mortar.
Tiling: Installation of tiles on the floor and walls according to the design plan. It's generally recommended to tile bathroom walls and floor before fitting the suite.
Ask any professional Tradesperson and they'll tell you that wall and floor tiles should go in first, before installing your fixtures and fittings. This allows for a more professional finish, and means avoiding awkward tile cuts to fit around fixtures.
Installing flooring before the shower can provide protection against possible leaks, making it easier to maintain and prolonging the lifespan of your bathroom suite. It also allows for smooth and efficient installation, ensuring a seamless finish for your renovation project.
We always advise fitting the shower tray before tiling the walls or installing wall panels as this ensures a more watertight seal around the sides of the tray.
Begin laying tile in the center of the room and work your way out. Lay a single row of tiles in both directions without mortar. Start at the center point and work outward. This dry layout will make sure your finished project will be centered.
Tiling is especially useful if your freestanding bathtub is positioned against a wall or near a shower fixture. While it's not strictly necessary, it can protect your bathroom and add a polished look.
If you're planning to tile around the entire room, it makes sense to tile before installing the vanity unit.
With placing the bathtub before the flooring and wall, you can better position the bathtub for protection and aesthetics. Without having to worry about damaging the flooring and wall, you can simply place the bathtub where you want and place the flooring and wall after to limit gaps between the two.
Tiles may break because of it. Or make mortar drips may happen that are challenging to erase while tiling the wall. Tiling the new floor will help prevent accidents if you decide to complete the shower floor first.
What this means in practical terms is that you should always remove the toilet if you are renovating it, in order to place tiles beneath the toilet on the new bathroom floor. The toilet flange then goes atop after you install tiles for the bathroom flooring.
We recommend having your tiles fitted before installing a sink, shower, bath and toilet. This means your bathroom suite can sit on top of the tiles, providing a better seal and finish.
Guideline for Bathroom Floor Tile Sizes
The size of your bathroom floor tiles can be quite subjective. From 4-inch to 12-inch - it's ideal that you choose a size that may not look very small or busy and at the same time, is easy to cut and lay. Generally, the 12-inch by 12-inch or 24-inch by 24-inch works the best!
Generally, the tile will extend past the edge of the tub one full tile including the necessary trim. Tile and trim can be installed using a trowel-able paste made from Portland cement mortar on a non-cured bed or dry set/latex modified Portland cement mortar on a cured bed.
For a shower enclosure, extend the tile and the backerboard at least 6 inches above the showerhead. For a tub surround only, install the backerboard and tile at least 12 inches above the tub. For a high-end look, take the tile all the way to the ceiling.
Bathtubs, believe it or not, will expand when filled with water. Leaving a 1/16″ gap between the tub and tile will prevent the tile from cracking when the tub expands. Plus, a 1/16″ gap allows the caulk to properly fill the space and waterproof the transition between the tile and tub or shower.