How to Plan a Bathroom
Tile Layout

Awkward sliver cuts at corners. Two-inch strips at the ceiling. A grout line that runs straight into the toilet flange. These are the things that make a beautifully tiled bathroom look amateur.

Tile layout is half the job. The other half is sticking it on the wall. Skip the layout and you'll spend the whole install fighting your own bad decisions.

Here's how I plan a layout before any tile gets ordered.

Step 1: Pick the focal wall

Every bathroom has one wall the eye lands on when you walk in. Usually it's the shower back wall, or the wall behind the vanity, or the wall behind the freestanding tub. Identify it before anything else.

The focal wall gets the cleanest layout. Full tiles centred on the wall, no awkward cuts at sightlines, full sheets running into the corners. Every other wall is secondary; the cuts can land on the secondary walls.

This sounds obvious but I've watched contractors start tiling at a corner because that's where their saw was set up. Don't do that.

Step 2: Centre the layout

Find the centre of the focal wall. Mark it with a chalk line. Lay your first row of tile centred on that line, working outward in both directions.

This guarantees the cuts at each end of the wall are equal. If the cut at one end is going to be a 2-inch sliver, the cut at the other end will also be 2 inches. Symmetric slivers read intentional. Asymmetric slivers read sloppy.

If the centred layout produces slivers smaller than half a tile width on each side, shift the centre line by half a tile in either direction. Now your cuts at each end are at least half a tile wide. Easier to install, easier to look at.

"The first tile placement decides the entire wall. Take an extra hour at layout and save yourself fifty hours of fighting bad cuts."

Step 3: Establish vertical and horizontal centre lines for the room

The same centring logic applies to the floor and to every wall.

For the floor: find the longest sightline (usually the wall you face when standing at the door) and run a chalk line perpendicular to it through the visual centre of the room. Centre your floor tile on that line. The cuts go to the side walls, not the front and back.

For each wall: vertical centre line for left-right cuts, horizontal centre line for top-bottom cuts. The horizontal line is usually the centre of the most-visible row of tile, not the centre of the wall height.

Step 4: Plan the cut waste

Standard waste allowance is 10% for square layouts, 15% for diagonal or running-bond, 20% for herringbone or anything with rotated tiles.

For Ottawa bathrooms, here's what I order:

• Floor tile, square layout: 10% waste. A 50 sq ft floor needs 55 sq ft of tile.
• Wall tile, running bond (subway): 12-15% waste. The 50% offset creates more cuts at corners.
• Herringbone or chevron: 20% waste. Every cut needs an angle.
• Large-format (24x48 or bigger): 12% waste even for square layouts; the cost of one cracked sheet is high.

Always order the waste at the same time as the field tile. Tile lots vary, and a re-order three weeks later may not match the original lot's colour.

Step 5: Decide where to start

For a shower, I start at the back wall (the focal wall), centre the layout, and work toward the side walls. Cuts land at the side walls and inside corners, where they're least visible.

For a floor, I start at the door (the wall you see first when entering) and work into the room. Full tile lands at the entrance; cuts land at the back wall, against the tub or vanity.

For wainscot or partial wall tile, I start at the bottom and work up. Cuts land at the top edge, hidden by a profile or trim. Never land cuts at the floor; they look unfinished.

Step 6: Spec the grout joint

Grout joint sizing is part of layout. Pick wrong and your layout math is wrong.

For Ottawa renovations, my defaults:

• Subway tile: 1/16" joint. Tight, modern, easier to clean.
• 12x24 large-format walls: 1/8" joint. Standard.
• 24x48 or larger porcelain slab: 1/16" joint, only with rectified-edge tile. Standard-edge tile won't sit flat enough at 1/16".
• Mosaic floor: 1/16" to 3/32" joint. Smaller looks tighter; bigger is more forgiving.
• Stone (marble, travertine): 1/16" with rectified edges, 1/8" with chiseled edges.

Grout colour matters too. Match-to-tile grout makes the wall read as one surface. Contrasting grout (white tile, dark grout) emphasizes the pattern. Pick before the layout because the visual rhythm of the wall changes completely.

Step 7: Thinset coverage and crack prevention

Layout planning includes the substrate, not just the tile face. Two things to spec:

Thinset coverage

For a wet-area shower wall, thinset coverage must be 95% minimum. For floors and dry walls, 80% is the code minimum. The difference matters because gaps behind tile in a shower are voids that hold water and grow mould.

Use the right notched trowel: 1/4" x 3/8" U-notch for floor tile up to 12x12, 1/2" x 1/2" square notch for large-format tile, and back-butter every tile larger than 16x16.

Anti-fracture membrane (Schluter Ditra)

Ottawa bathrooms get seasonal subfloor movement from temperature swings. An anti-fracture membrane between the subfloor and the thinset prevents tile cracks at the grout lines.

Schluter Ditra adds a modest line item to the floor cost and extends tile life from 10-15 years to 25+ years. Every tiled bathroom floor I install gets it. Non-negotiable.

The chalk-line dry-lay

Before any thinset hits the wall, I dry-lay the entire focal wall on the floor in front of it.

The dry-lay sequence:

1. Snap the centre line on the wall
2. Lay one full row of tile flat on the floor against the wall, with spacers, centred on the chalk line
3. Measure the cut at each end. Adjust the centre line if needed to balance the cuts.
4. Mark the lower edge of the lowest full row on the wall (this is your starting horizontal line)
5. Snap a level horizontal line at that mark across the entire room
6. Begin tiling from that line, working up. The bottom row gets cut last, after a full layout has set.

This takes an extra 90 minutes. It saves a wall full of regret.

Common layout mistakes

What I see go wrong on the projects I get called in to fix:

• Starting at a corner. The corner is rarely plumb or square. Starting there means every tile inherits the corner's error.
• Ignoring sightlines. A grout line running into a sink drain looks broken. Plan the geometry around drains and fixtures.
• Not pre-sorting tile by lot. Within a single tile order, batches vary. Mix tiles from multiple boxes during dry-lay so any colour variation distributes across the wall.
• Mismatched joint sizes. 1/8" floor joints meeting 1/16" wall joints look bad at the floor-wall transition. Pick one joint size for the whole bathroom or transition with a Schluter profile.
• Not accounting for the schluter trim. Edge profiles (Schluter Jolly, Reno-T, etc.) are part of the tile width. Subtract them from the cut math, not after.

What this means for your project

If you're hiring out a bathroom renovation in Ottawa, ask the contractor: "Where do the cuts land on the back wall? Where does the centre line go? What's your dry-lay process?"

If they hesitate or wave you off, they're not planning the layout. They're going to start at a corner and you're going to get slivers.

If they walk you through the centre lines, the cut math, and the dry-lay sequence, you've got the right contractor.

Dream Touch has tiled over 500 bathrooms in Ottawa since 2005. Every job starts with a dry-lay before any thinset opens. Free 48-hour walkthrough on your project at 613-862-4555.