Tiling a sloped shower wall

Last year we boldly took the plunge into a long overdue bathroom renovation.

This included moving the tub 6″ away from the sloped wall, and replacing the 60’s era tileboard shower surround with 6″x 6”ceramic tiles, edged with 2″ bullnose border tiles.

While tiling a shower was uncharted airspace for me, I had full confidence in my “wingman” – Mr Google.

When it came to dealing with how to tile the slope, I found precious little online info that was of real help. But I did run across one picture that kept me from making a goof that would have driven me nuts for the rest of my life. More about that later.

Where to start

Since the most visible part of the sloped wall is at eye level and the top edge, that’s where you start.

Marking the Guidelines

• Tile the adjacent wall up to full height, including any edge or border tiles. This is your reference for the top edge of the tiles on the sloped wall.
• Use a level to mark a pencil line on the sloped wall, level with the top edge of the previously installed tile.
• If you’re using an edge or border tile, place the top edge of one on the marked line, and butt a full tile (with the spacers, if your using them) against the bottom. Mark the top edge of the full tile on the backer board. Use a level to extend this line across the width of the area you’re tiling.

(This is where I almost goofed!) Don’t even try to figure out how to line up the grout lines between the sloped wall tiles and the flat wall. The laws of geometry dictate that this can’t happen. The important line is at the top edge of the entire tiled area.

• If you’re not using a border tile, line up the top edge of the FACE of the tile on the slope with the top of the adjacent tile (this compensates for the thickness of the tile).
• Mark the vertical line where the tiled area will end on the sloped wall. You should mark lines for both the field tiles and the border. Extend both lines down to the tub or floor, to make sure everything lines up the way you want it. Use full tiles at the top and outside edge.

  This means your cut tiles should be down at the bottom of the slope and at the inside corner, where they’re less visible.

Installation

I honestly didn’t know if the tiles would fall off or slide down the wall. So I tried one. Fortunately, it wanted to slide – I could deal with that. The thinset mixture and tiling technique are the same as tiling a flat wall , except you work from top to bottom. Uh…Um….and the gravity thing.

Before you start, make sure you have a roll of masking tape and staple gun within reach.

• Apply the scratch coat of thinset to the sloped wall according to the product instructions.
• Tear off four 6″ strips of masking tape and stick them lightly to the wall within easy reach.
• Apply thinset to the upper tile area, just enough for the first row of tiles.
• Grab two tape strips and stick them firmly to a full field tile, leaving about half the length above the tile to stick to the wall.
• Set the first tile at the outside corner. Make sure it’s lined up with the correct vertical and horizontal guide lines.
• Press the tape onto the wall keeping tension on the tape. Staple the tape to the wall as close to the tile as possible without tearing the tape. Check the position of the tile and adjust it if required. Add additional tape strips at the bottom if it wants to slide.
• Repeat this process to continue the top row of tiles moving towards the inside corner at the flat wall. You should only need one spacer between tiles (besides they’ll fall out if the tiles aren’t close enough together). Keep checking that you don’t bump any tiles out of line as you work. The tile at the inside corner will likely need to be cut.
• Let this top row set up enough that the tiles won’t move (about a half hour or so should do it). 

The Rest is Easy

• Apply the thinset for the next couple of tile rows.
• Use the same procedure as on the first row. The only difference is that you tape the tiles to the row above. By the time you get through one row, the last one should be set. If not, don’t rush it. Work on something else for half an hour.
• Leave all the tape strips on so the top rows continue to support the lower ones until they set.
• The bottom row of tiles will likely need to be cut where it joins the knee wall.

Finishing

Finish up by adding the border tiles and let everything set for 24 hrs. Grout the slope the same way you do the flat walls. You might want to use caulk instead of grout at the joint between the slope and knee wall if you think there’s a chance of any wall or roof movement.

Tile Size Caution

I’d be comfortable doing this job again with up to an 8” x 8” wall-type tile. I would think long and hard before I’d try it using larger size tiles due to the weight, and possibly consider it a job best left to the pros.

Note on the Shower Rod:

The distance between the “wet wall” and the slope at rod height is about 48″. The shower rod is a Moen curved adjustable length rod with a custom DIY holder at the sloped wall.