Bathroom tile floor have questions

[Eman85]

I'm a homeowner doing a bathroom renovation. I've worked in mechanical trades but have never done tile work before. It's a small bathroom that I gutted to the studs. Right now the tub is in and the walls are sheetrocked. Since it's a small bathroom I figured it would be a good place to learn tile work, tiled section is 5'x5'. I'm at a point where I have some questions/problems. The bath floor will be 1/2" Durock with tile on it. The hall leading to the bath has nothing right now but will have laminate. The door has not been hung yet, using a pre-hung door with a 2 piece jamb. This is where I have questions about how to end the floor and how to install the door. I have looked at a marble style threshold which I thought might make it neater.
Do I install the door and jamb first? Should I just tile to the middle of the jamb or better using the threshold?
Any tips would be appreciated. As you can see I'm confused. Thanks in advance!

[Kman]

Welcome to the forum, Emil.

Your tile would typically terminate directly under the door. However, if you're using a marble threshold, you'll want that directly under the door, with the tile butting up to the threshold, minus a small joint that gets caulk for expansion.

I would hold off on installing the door until the tile is installed and grouted. It makes it easier to install the tile and the door. Of course, you'll need to know where the door will sit. If necessary, set it in place and mark the location of the door on the floor for reference.

[Eman85]

OK so if I tile without the threshold I would put cement board to the center of the jamb under the door and tile to there. If I use the threshold trial fit the door and the threshold and cement board and tile to the threshold leaving a gap for expansion that I would caulk. So by marking where the door jamb is I would tile to it but not under it? If I tile under the jamb that would raise it above my hall floor. If I set the jamb on the subfloor the door will be close to the tile. Would spacing the jamb up 1/2" to keep a good gap under the door be a good idea? I don't want to have a problem and have to cut the door later.

[jadnashua]

Unless you want it for keeping the finished floor at a particular thickness, there's no other functional reason to use the more expensive, heavier 1/2" sheets on a floor versus the 1/4" stuff, and if you want things even thinner, something like Ditra membrane is about 1/8" when installed, so thinner than the 1/4" CBU. Cement board has no useful strength for use on a floor. When tiling a wall, with one exception, you want 1/2" stuff if you follow the manufacturer's instructions.

[HooKooDoo Ku]

Right or wrong, here's how I did a threshold

Rather than use one of those marble threshold, I made a custom piece out of an 24"x24" tile I found in a matching color and cut a strip out on the diagonal.
As you can see, I positioned the threshold such that when the door is closed, you don't see the threshold from inside the bathroom, but you do see it from the hallway where carpet later meets the threshold.

For more pictures showing the colors I used, here's a link to post where I shared several pictures of the 1st tile job I did with the help of this forum.
My 1st Tile Job

[Eman85]

Thanks everyone for the welcome and the suggestions.
I'm using 1/2 cement board because of the OSB subfloor that isn't 3/4". I've already set the cement board under the tub so I'm committed.
The pics are great and the link. The tile idea would be an option but the threshold isn't expensive so I'm leaning that way.
The laminate on the other side will require a gap at the threshold so I'm thinking a transition strip between the laminate and the threshold is an option.
Still concerned about under the door clearance so I was thinking of spacing the jamb up 1/2" to gain some clearance. I framed at 82 1/2" height just for this reason. m
@HooKooDooKu How wide did you make the threshold? Is that carpet on the other side? I'm guessing your door was already in place and you cut the tile to fit around the molding instead of going under, did you caulk the tile to the molding?

[cx]

Welcome, Emil.

Originally Posted by Emil

I'm using 1/2 cement board because of the OSB subfloor that isn't 3/4".

The thicker CBU will not compensate for an inadequate subfloor. Do you know exactly what you have for a subfloor?

Have you also evaluated your floor joist structure to determine if that qualifies for a ceramic tile installation?

[Eman85]

Subfloor is 5/8" joists are 16" on center.

[Kman]

5/8" is the bare minimum for subfloor. Adding a layer of 1/2" plywood would be better.

The way Joseph did his floor will work. But generally you want the break between two types of flooring to fall directly under the door, not the door jamb.

[cx]

Type, size, and unsupported span of the joists, Emil?

[HooKooDoo Ku]

Originally Posted by Eman85

@HooKooDooKu How wide did you make the threshold? Is that carpet on the other side? I'm guessing your door was already in place and you cut the tile to fit around the molding instead of going under, did you caulk the tile to the molding?

The door was already installed when I started working on the tile.

None of the tile is under the door frame.
The threshold was cut to only the width between the door jam (those 1x2 strip thingees that go down the center of the door way).
This left a small "hole" on the bathroom side of the door frame where the threshold was deeper than those 1x2.

You can make out the small space in the pictures where the tile was roughly cut to follow the profile of the molding.

I think I used color-match silicon around the door frame (might have simply been grout as I don't see a major color difference).

At the time of the picture, that's just the basement concrete slab you see. I simply installed tile directly to the concrete.
Later, the hallway outside the bathroom was covered with 3'x3' carpet squares with integrated padding. All the rooms in this finished basement had those carpet squares (playroom, hallway, office/storage).

Tile on bare concrete has worked out well. The concrete had cured for over 10 years and I was even able to ignore cracks in the concrete that hadn't moved since we moved into the house. I was initially worried the concrete might feel too cold. But it's temperature has felt fine.

[Eman85]

CX,
The floor has 2x8's and there is a support beam directly under the bathroom section that will be tiled so it is fully supported.

[Eman85]

Hoo Koo Doo Ku
I see it now where the threshold goes just short of the jamb and that you cut tiles to fit around the door jamb molding.
I was hoping to not cut at the jamb since I don't have a jamb in place yet. That's the reason for starting this thread.
I'm already committed with the 1/2 cement board as I started under the tub and into the floor area already.

[cx]

Originally Posted by Emil

The floor has 2x8's and there is a support beam directly under the bathroom section that will be tiled so it is fully supported.

That is more likely to be a problem than a blessing, Emil. You now need to consider the unsupported span of the joists on either side of that beam, and also the method in which the joists ends were treated over the beam.

What do you know about that particular part of the structure?

My opinion; worth price charged.

[jadnashua]

Where the joists meet over a beam, when they deflect, the ends can bend upwards via the lever effect. That can be enough to crack a rigid tile. It's not the size of the room, it's the length of the unsupported joists that are more critical.