[dtbingle]

Standard 5' alcove bathtub installed and stuck on what to do with the first row of wall tile.

The bathtub deck is 1/8" out of level across the 5' tub. If full tiles are used, I feel like having one side with a 1/8" tile-to-tub caulk gap vs. 1/4" at the other end is going to look bad. This means cutting the first tile row to match the slightly out of level tub deck.

Tiles being used are 4x16 white subway tiles
1) How much do you cut off of the height on the first row of wall tile along the tub? Some of the things I've read say that you should cut to 3/4 height or less because cutting slivers off of full height tiles is real noticeable.

So if the 4x16 tile is cut @ 3/4 height, that leaves 3" of tile height, which leads to the 2nd question.
2) With 3" of tile height, how much tile needs to be mortar'd to the cement board vs. hanging past the cement board towards the tub deck to maintain proper adhesion and durability over time?

For example, with the CBU sitting 1/8" above the 1" tub flange and desire a 1/8" caulk gap for tile-to-tub, that means with 3" height tile, 2" will be stuck to the CBU, and 1" will be floating over a gap. Is this enough?

 

[DIYOkie]

Curious to see what any pros might say on this.

I'm not a pro, but we've remodeled and flipped so many houses and tile is one of our strengths. There's no way I'd cut that bottom row of tile to worry about that 1/8" difference.

First of all, I've never met a tile saw that can cut within 1/16" of accuracy anyway, especially long cuts. Closest would be a score and snap, I can get quite accurate with it.

Second, and most importantly, that can be made up with tile spacing as I work up the wall, easy. Even 1/8" grout lines can provide all you need to gently bring that up.

Or..just go with an 1/8" gap on one end and 1/4" gap on the other, leveling it out on the first row with full size tile, and just do the caulk line so it's a 1/4" 'look' on both ends.

I do not see how 1/8" can be noticeable across a 5' span.

To answer your question, I would think 2" is enough to hold a tile - but I'm not sure if that's enough to support the pieces on the subtending rows as it's hardening. That would be my concern. Might be a good idea to do that first row and then let it harden before you continue up.

 

[dtbingle]

Curious to see what any pros might say on this.

I'm not a pro, but we've remodeled and flipped so many houses and tile is one of our strengths. There's no way I'd cut that bottom row of tile to worry about that 1/8" difference.

First of all, I've never met a tile saw that can cut within 1/16" of accuracy anyway, especially long cuts. Closest would be a score and snap, I can get quite accurate with it.

Second, and most importantly, that can be made up with tile spacing as I work up the wall, easy. Even 1/8" grout lines can provide all you need to gently bring that up.

Or..just go with an 1/8" gap on one end and 1/4" gap on the other, leveling it out on the first row with full size tile, and just do the caulk line so it's a 1/4" 'look' on both ends.

I do not see how 1/8" can be noticeable across a 5' span.

To answer your question, I would think 2" is enough to hold a tile - but I'm not sure if that's enough to support the pieces on the subtending rows as it's hardening. That would be my concern. Might be a good idea to do that first row and then let it harden before you continue up.

Thanks your explanation made perfect sense. The only part I didn't follow was about the 1/8" grout line and gently bringing it up. The tiles have built-in side spacers to leave 1/16" lines, however, I'm planning to use an additional 1/16 spacer for 1/8" grout line total. Are you saying that the first row could be slightly off level to maintain a more consistent caulk gap to the tub, but then maneuver the first few rows of tile so that the grout lines are slightly more or less than 1/8" to return the tile rows back to level?

Stuck between a few options based on your recommendations:
Option 1:
-Use full 4x16 tiles for the first row and leave 1/16" gap between tub and tile on one end and 3/16" gap on the other.
-Lay down a tape line level with the 3/16" gap and run caulk across to have a consistent 3/16" caulk line appearance
-Starting with a full tile leaves 5/8" sliver at the ceiling (boooo)

Option 2:
-Cut first tile row down to 3" height at slight angle to create even 1/8" gap between tile and tub to caulk
-May have wait for first row mortar to harden before progressing upwards
-Reducing first tile row height by 1" means last tile near ceiling would be 1 5/8" tall instead of a 5/8" sliver.

Option 3:
-Follow Option 1 and start with full height tile for first row
-End the wall tile @ 3/4 shower wall height instead of bringing to ceiling to eliminate sliver at ceiling

Not a huge fan of the accent strip mosaics to make up the small height difference and that means additional $$.

 

[Nealtw]

I would place the one tile where I want it, where the space is biggest, then draw level lines off that, cut the rest of the tile to fit that line.



For the gap at the top, do the math, maybe adding 1/16" or less to each space going up

 

[DIYOkie]

Thanks your explanation made perfect sense. The only part I didn't follow was about the 1/8" grout line and gently bringing it up. The tiles have built-in side spacers to leave 1/16" lines, however, I'm planning to use an additional 1/16 spacer for 1/8" grout line total. Are you saying that the first row could be slightly off level to maintain a more consistent caulk gap to the tub, but then maneuver the first few rows of tile so that the grout lines are slightly more or less than 1/8" to return the tile rows back to level?

Yep, that's exactly what I was saying.

Stuck between a few options based on your recommendations:
Option 1:
-Use full 4x16 tiles for the first row and leave 1/16" gap between tub and tile on one end and 3/16" gap on the other.
-Lay down a tape line level with the 3/16" gap and run caulk across to have a consistent 3/16" caulk line appearance
-Starting with a full tile leaves 5/8" sliver at the ceiling (boooo)

Yeah, bummer, that sucks.

Option 2:
-Cut first tile row down to 3" height at slight angle to create even 1/8" gap between tile and tub to caulk
-May have wait for first row mortar to harden before progressing upwards
-Reducing first tile row height by 1" means last tile near ceiling would be 1 5/8" tall instead of a 5/8" sliver.

Definitely better.

Option 3:
-Follow Option 1 and start with full height tile for first row
-End the wall tile @ 3/4 shower wall height instead of bringing to ceiling to eliminate sliver at ceiling

Not a huge fan of the accent strip mosaics to make up the small height difference and that means additional $$.

Decisions, decisions. I actually love installing mosaics, but they can be tricky if you have to cut little pieces on the tile saw if you're not comfortable getting your hands that close to the blade. I play guitar and drums so I have my wife do it!

You could also use a piece of trim up top for that 5/8" gap, per option 1. Get some material as thick as the tile to fill in the space, then cut a piece of composite white trim and just finish nail it and caulk. Cheaper than mosaic, at least.

 

[DIYOkie]

For the gap at the top, do the math, maybe adding 1/16" or less to each space going up

That sounds like a good plan right there.

 

[Nealtw]

That sounds like a good plan right there.

I learned that the hard way and have to look at it every time I sit in the bathroom. :wink2:

 

[dtbingle]

For the gap at the top, do the math, maybe adding 1/16" or less to each space going up

Good advice! If the first row is cut to 3” and the grout line size is reduced from 1/8” to the built-in 1/16” lugs only, it will leave 2 3/4” at the ceiling instead of only 1 5/8”.

This works out good to keep a consistent caulk gap at tub, leave a tall enough first tile row to adhere to the cement board and hang over the gap to the tub, and to have a good sized piece along the ceiling too.

 

[huesmann]

Get the bottom edge as close as you can, as you install. Top edge of the bottom row of tiles should be level. Bottom edge will be slightly stepped. Once you run a bead of caulk below, unless your row of tile is very short, you won't be able to notice a big difference.