Large-format tile is the look most of our clients want now: 24 by 48 porcelain on a bathroom wall, 1.2 by 2.4 metre slabs in a shower, floors that run through a main level with a grout line every metre. It reads as architecture. It also hides nothing, and most of what goes wrong with it went wrong before the first tile was set. Here’s what has to be true.
The substrate has to be flat, and flat has a number
A small tile follows the floor. A big tile bridges it. If the substrate dips two millimetres over a metre, a 12 by 12 rides down into the dip and out again and nobody notices. A 24 by 48 spans the dip, one corner sits high, its neighbour sits low, and you feel the edge underfoot and see it in raking light every day. That edge is lippage, and it’s the single most common complaint about large-format work.
The industry standard for tile with any side over 15 inches is roughly three millimetres of variation over three metres, and about one and a half millimetres over 30 centimetres. Almost no floor or wall in a Lower Mainland home meets that as built. Older homes in Vancouver and Burnaby are nowhere close. Newer homes in Richmond and Surrey are better and still off, because framing keeps settling for a couple of years after handover. So the first thing we do on a large-format job is put a straightedge on every surface, and the first line in the quote is what it will take to get flat.
How we get there
Floors over wood get stiffened where they flex, then flattened with self-leveller or a mortar bed, then an uncoupling membrane so the tile and the subfloor can move independently. Concrete slabs get ground at the high spots and filled at the low ones. Walls get checked for plumb and flat; where framing is out, we shim it or hang a new substrate rather than trying to float mortar thick enough to hide it. Cement board goes on flat and screwed to spec. Then we check again before the membrane goes on in a wet area, because a flat wall that’s later covered in a lumpy membrane is no longer flat. Our floor tile page covers the floor side.
Full coverage, or it cracks
Large tile needs mortar under all of it. Hollow spots become cracks when something heavy lands on the tile or a chair leg finds the void. We use a large-format thinset that holds its ridge under a heavy tile, comb it in straight lines so air can escape, and back-butter every piece so the two layers of mortar collapse into each other. Then we pull the first few tiles to check coverage before we trust the process for the rest of the room. It’s slower than setting small tile. It’s the job.
Leveling systems
Clips and wedges, or spinning caps, set between tiles while the mortar cures hold the edges flush and keep the tile from settling unevenly overnight. We use them on every large-format floor and wall. They don’t replace a flat substrate; they hold a flat result on a substrate that’s already been made flat. A contractor who says the leveling clips will fix the floor is describing a floor with lippage locked in.
Cutting and handling slab
Porcelain slab panels are cut on a rail system with a scoring wheel and snapped, then finished with a wet saw or a hand grinder for openings and mitres. Two people move them with suction frames. A slab wall is measured and templated before the adhesive is mixed, because there’s no adjusting a panel once it’s up. The tile is expensive enough that a bad cut is a real cost, which is one reason large-format labour runs higher: the planning is longer and the tolerance for error is smaller.
Where the seams go
On a wall of 24 by 48 the layout is about the grid: where full tiles land, where cuts hide, how joints line through from the wall to the floor and around the room. On a slab wall the layout is about one or two seams. Behind the glass panel, at an inside corner, centred on the wall as a deliberate line. Bookmatched slab, with the veining mirrored across the seam, turns that seam into the design. Our Calacatta wet room does exactly that across a shower corner; the custom tile installation page covers the layout work.
Large tile in showers
Big tile on shower walls gives the quiet, continuous surface that makes a bathroom feel like a hotel, and it makes the waterproofing more important, not less. Fewer joints means fewer places for a leak to announce itself early. We build large-format showers on a Schluter membrane over a substrate flattened for the tile size, plan the niche edges to land on joints, and mitre the outside corners so there’s no metal trim. Large tile on a shower floor only works with a linear drain and a single-plane slope. With a centre drain the floor has to be cut into a pattern or done in mosaic. Read what’s behind a tiled shower for the assembly.
Movement joints
A long floor of big tile still moves with the house. Soft joints filled with colour-matched silicone go where the floor changes direction, meets a wall, or runs long. In an open plan that runs porcelain across the whole main level, they’re planned into the layout at doorways so they read as part of the grid. Skip them and the floor will make its own, through a tile.
What to ask an installer
- How do you check flatness, and to what tolerance?
- What’s in the quote for prep?
- What thinset, and do you back-butter?
- Do you use a leveling system?
- Where will the seams go on the slab wall, and can I see the layout first?
Good answers to all five are what separates large-format tile that looks like architecture from large-format tile that looks like a mistake in raking light. It’s most of what we do in the newer homes across West Vancouver, the rebuilds in Richmond and the new construction in Surrey, and we’ll show you the straightedge on the first visit.
Request a quote with a photo of the room and the tile you’re considering. We’ll start with the flatness.