Beginners guide to tiling a bathroom floor

Just a few months before we put our Texas house on the market, we completed the master bath project by tiling the floor and replacing the baseboards.

For more than 28 years, we lived with a horrible dirty secret: carpet in our bathroom. And yes, that carpet was as disgustingly gross as you might imagine.

I recall a day when one of our kids, who shall remain nameless, overflowed the toilet onto the carpeted floor with enough fluid, shall we say, to damage the livingroom ceiling below it.

That should have prompted us to remove it, but I cleaned it and dried it as best as I could because I knew a massive bathroom remodel was in our future.

Who in the 1990s decided carpet in bathrooms was the way to go? When we bought the house brand new in late 1995, we requested that the carpet in the kids’ bathroom be replaced with vinyl, which we updated to tile several years ago.

Just days before we put the house on the market, the Fix-It Farmer replaced the carpet in the powder room (and all the other flooring on the first floor) with luxury vinyl planks. But that’s a post for another day.

Back to the master bath…

I don’t know why it took us so long to get the carpet out of there. Just the craziness of life, limited time and limited budget, I guess. We’d removed sections of it around the new shower, and we’d also thrown out some of the disintegrating pad.

But there was still about 70 percent of the O.G. carpet and we knew it HAD TO GO!

Out with the Old

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The Fix-It Farmer took out all the carpet, cutting and rolling it in 4-foot lengths so the garbage collectors would take it. The padding went into black trash bags.

If you have ancient carpet and pad to remove, it’s a good idea to dig out one of those N-95 masks in the back of your cabinet to save your lungs.

You’ll also need to remove the tack strips around the edge and the baseboards.

Small pry bars and a hammer or mallet are great for the tack strips and for the baseboards if you don’t plan to re-use them.

Here’s a great mini pry bar from Amazon.

We broke enough baseboards in the process that we had to replace them. We got smart before tackling the whole first floor and bought a baseboard pulling tool, which worked so much better than the simple pry bar.

Then you want to check the subfloor for level, patching any low spots and sanding high spots. If you’re working with a wood subfloor, this is a great opportunity to screw down any squeaky parts.

Cement backer board base

Next, you install cement backer board to support your mortar, tile and grout.

For the floor, the Fix-It Farmer used a scoring tool on the 1/4-inch cement board. He had a metal straight edge and ran the tool over the line to cut multiple times before he snapped off the smaller piece.

For a few tricky cuts, like an “L” or an angle, he used the circular saw with an old blade or his Milwaukee oscillating multi-tool for smaller, more precise cuts.

The hole for the toilet or any plumbing can be cut by drilling pilot holes with a masonry bit and then removing the rest with the multi-tool.

Whichever method you use, expect LOTS of dust. Wear a mask and work in a well-ventilated area. FIF cut pieces in the garage with the door open.

You can make cardboard templates for any complicated cuts. In addition to the hole for the toilet, we had an angled door into the water closet. I also used cardboard templates when I cut the actual tiles.

Remember to leave 1/8 inch gap between sheets and next to the wall. Also, stagger the seams so you don’t have the same seam for multiple boards.

To secure the backer boards, you use both thinset mortar and special cement board screws.

The combination of mortar and screws means you have a reinforced, solid surface for tiling.

Once all the boards are down, tape all the seams with mesh alkaline-resistant tape specifically made for cement board and cover the tape with thinset mortar to make a smooth, leak-proof surface.

At this point, we cut a little sliver from the bottom of the door jambs to allow the tile to slide under them.

The Milwaukee multi-tool made quick work of this. I used a little scrap piece of tile to help me set the height. It you don’t have one of these handy tools, they make a little saw specifically for this purpose, which we’d used in the past.

Dry fitting tile

We used 12×24 inch porcelain tiles that match the tiles in our shower (completed two years earlier). Shortly after I purchased all the tiles for the project, they disappeared from the shelves at Lowes.

I thought I’d bought enough, but I was worried about running out.

This concern prompted me to do a dry fit of the whole bathroom before I put anything down. Our master bath is almost 100 square feet and has some tricky angles with the aforementioned water closet and the shower we enlarged.

What would I have done if I’d run out? I might have put a different tile in the linen storage closet or gone with another tile as a border. I had leftover marble subway tile I could have used that would match the shower.

But I didn’t want to mess with that. I wanted to hit “the easy button” as much as I could.

Before I cut any tiles, I figured out my pattern.

The wall you see when you walk in the door has 8 feet for vanity space. I bought 2 36-inch vanities, then my talented father in-law built a slightly shorter 24-inch shelf unit to go in between them.

I painted it to match the vanities, and we put a marble tile on top of it. It was only a foot deep instead of 22 inches like the two vanities on either side of it, so a full width tile cut almost in half lengthwise fit the space.

I also made sure to trim the first row next to the vanities and the last row in front of the door. You don’t want a tiny sliver in either spot so you adjust the width of the tiles accordingly.

I started by drawing a straight line from the outer corner of my vanity to the doorway.

I overlapped the rows by a third of a tile, or 8 inches. Fortunately for me, hubby had a metal square with one leg that was exactly 8 inches. This helped me position the tiles quickly.

I marked tile corners on either side of my straight line, so I’d know where to put mortar to preserve my walkway in the middle.

We used a tile saw like this for most of our cuts.

We had tile nippers and a Dremel rotary tool for a few cuts. Those around the angled doorway into the water closet required a little Dremel action or a file to grind away a bit of porcelain for a better fit.

I laid out the entire bathroom floor, including spacers, before mixing any mortar. That’s what I recommend for anyone who hasn’t done a ton of tiling.

After the dry fit, I collected all the cut tiles working from top to bottom and from the sides of the room to the middle and set them in a staging spot in the adjacent master bedroom. A few of the tiles I marked with blue tape and marker, which you could do with all your cut tiles so you don’t waste time figuring out which tile goes where.

Mortaring and grouting to the finish line

Then we mixed up a batch of mortar designed to hold large-format tiles. You don’t want to mix up more than you can handle in about an hour because it WILL dry out.

For smaller projects, like a kitchen backsplash or a tiled fireplace (both of which I also did before we sold our Texas home), I’d recommend a tub of premixed mortar. It just makes life easier when you can put the lid back on the tub and use it again hours later or the next day.

The size and shape of the notches on the trowel will be based on your tile size. Ask the Google, if you’re unsure.

With our 12-by-24-inch tiles, we used a 1/4 inch x 3/8 inch square notched trowel. You want nice, even ridges running in the same direction as your tile. I also put a thin layer of mortar on the back of every tile to insure it had good coverage; that’s called back buttering in the tile biz.

When you set your tiles in place, you’re going to want to use a tile leveling system. Don’t worry. It sounds more intimidating than it is. It’s really just tile spacers with a hole for a wedge, and a special tool to secure the wedge that spans adjacent pieces of tile. The wedges make sure that your tiles are giving you no lip. Really. Lippage is when adjacent tiles are not in the same plane, so you feel a ridge in between them.

You’ll need different spacers next to the walls and tub. I used both tiny plastic wedges that you can combine for proper spacing and rubber/plastic cross spacers.

It’s a good idea to have an old small flathead screwdriver to clean any wet mortar that squeezes up between tiles so your spacer doesn’t get stuck when the mortar dries.

I started out by tiling along the bathtub because it didn’t have any tricky angles. A good warmup, in other words.

Once I laid all the tile from the tub to the middle of the doorway, I switched to the water closet on the opposite side of the room and began working my way back to the middle of the doorway.

You want to avoid stepping on tiles before the mortar is dry, so you’re tiling your way out of the room.

Wait 24 hours before walking on the tile.

Once the mortar is dry, you wiggle out the wedge in the tile leveling system and use a rubber mallet to whack the side of the spacer and it flies off the floor, sometimes traveling more than a dozen feet. Or hitting your partner in the back. Very satisfying.

If you don’t have a mallet, you can kick the spacers free.

Then scrub any residual dried mortar off the surface of the tile and prepare to grout.

Just like with the mortar, you don’t want to mix up too much grout at once because it will get too dry.

Use a grout float to press grout between tiles. Wait a bit and carefully wash off any grout on the surface of the tile with a damp (not dripping) sponge.

When I finished a section, I went over it a second time with the damp sponge to remove the grout haze.

For any edges along the tub and walls, use caulk not grout. I purchased caulk that matched the grout, which made for a seamless look along the shower and tub walls.

After replacing all your baseboards to cover the gap between the tile and the wall, you can caulk where the tile meets the trim or the door jamb.

That’s all, folks! It’s not easy, but it’s doable with some planning and patience.

Related links:

Planning a budget bathroom remodel

How to get more bang for your bathroom remodeling buck

Behind the walls on a bathroom remodel

How NOT to DIY your shower pan

Tips for tiling a large shower