3. Materials
Tile size, adhesive, grout, layout pattern, and everything else a room needs.
Tile size, adhesive, and grout
For each room, choose a floor tile size and (if wall tiling is on) a wall tile size - they don't have to match. Adhesive type affects how much coverage you get per bag: standard adhesive suits typical ceramic tile, premium is for wet areas needing a stronger bond, large-format adhesive is needed for tiles 600mm and up to stop them sagging before the adhesive sets, and tile-on-tile is for retiling directly over an existing tiled surface. Grout joint width is mostly about the tile's own edges - wider joints (5mm) suit rustic or handmade tile with uneven edges, narrower joints (2mm) suit precision-cut rectified tile, and 3mm is a safe default for most machine-cut tile.
Layout pattern - and why it changes how much you need
How the tiles are actually laid affects how much gets wasted in cutting. A straight grid wastes the least; a diagonal or herringbone layout wastes noticeably more, because the cuts at the edges of the room are angled and the offcuts don't reuse well.
Floor and wall can use different patterns - a herringbone floor with a plain grid on the walls is a common combination. By default, the wall uses whatever pattern the floor is set to; there's a link to give the wall its own pattern if you want one.
Where the wastage percentage actually comes from
You'll see a wastage percentage shown next to each surface once a pattern is chosen - this isn't something you type in, it's worked out from the pattern and the room's own size. Smaller rooms waste proportionally more than larger ones at the same pattern, because a fixed amount of edge-cutting is a bigger share of a small room's total tiles than a large one's. A registered account can override this figure manually if a specific job needs it, but for most rooms the computed figure is a sensible starting point.
That bathroom's floor came out to 34.25 sq ft after the bath tub was deducted - well under the 50 sq ft cutoff for a "small" room, so it lands in the small-room wastage band. With a standard grid tile and a 300 × 300mm tile size:
34.25 sq ft ÷ 0.97 sq ft per tile ≈ 35.4 base tiles. Adding 10% wastage for a small room brings that to 38.9, rounded up to 39 tiles. The bath tub ticked earlier adds its own allowance - 2 tiles per fixture, one fixture - for 41 tiles in total.
At 10 tiles per box, that's 5 boxes - 50 tiles delivered against 41 needed, so 9 spare. See Your results for how spare tiles are shown on the results page.
What else do you need? (sundries)
Toggle whichever of these apply to a room - each is worked out from that room's own dimensions:
- Tile trim - edge strips for exposed tile edges, like an open threshold or where floor tile meets a different flooring. Not usually needed where tile meets a wall.
- Spacers - keep the gaps between tiles even while the adhesive sets. The quantity is based on how many tiles the room needs.
- Silicone - a flexible seal for internal corners and where tile meets a fixture like a bath or basin, since grout would crack there instead of flexing with the joint.
- Primer - helps adhesive grip certain surfaces, like painted walls or a very smooth, glossy surface being tiled over.
- Waterproofing - a membrane applied before tiling to stop water reaching the structure underneath. Typically bathrooms, balconies, and similar wet areas.
- Sealer - protects natural stone from staining and moisture. Not needed for glazed porcelain or ceramic.
Skirting
A thin strip of tile along the base of the wall, usually cut from the same tile as the floor - though you can pick a different tile for it specifically if the job calls for it. It's always shown as its own separate line in the results, never merged into the floor tile count, since it's genuinely a different material decision even when it happens to come from the same tile.