On this page
Most of what makes tile last disappears from view once the job is finished. Tile is rigid and brittle, so it depends on a stiff, flat, clean base, and in a shower it depends on a waterproof layer behind it, because grout and tile alone don't stop water. Wood-framed floors that flex, slabs that crack with the seasons and dry winter air all put stress on a tiled surface, which is why the prep and membranes matter as much as the tile.
This page covers tile materials, floors versus walls and showers, substrates and membranes, layout and grout, heated floors, silica dust from cutting, and repairs. The flooring contractors page compares tile with other floor coverings.
Ceramic, porcelain and natural stone tile: how the materials differ
- Ceramic tile: a fired clay body, usually glazed on top; lighter and easier to cut, it suits walls, backsplashes and floors with moderate traffic, but a chip reveals the colour of the body underneath.
- Porcelain tile: a denser body fired at a higher temperature that absorbs very little water; it suits floors, entrances, showers and heated floors, but it's heavier, harder to cut and needs a mortar made for dense tile.
- Colour-body porcelain: the colour runs through the tile or close to it, so chips show less, a real advantage on busy floors.
- Natural stone: marble, slate, granite, limestone and travertine are each unique, but many are porous or sensitive to acids, need sealing and vary in thickness and shade from piece to piece.
- Large-format and thin tiles: big panels look almost seamless but demand an exceptionally flat base, careful handling and often a specific trowelling method set out by the maker.
Floor tile vs wall tile vs shower tile, and slip resistance where it's wet
- Floors: tile has to handle foot traffic, furniture and dropped objects, so check that the maker rates the product for floors and, at an entrance, for grit and winter slush.
- Walls and backsplashes: with no traffic, thinner, lighter or glossier tile works, though some wall-only tile is too soft or slippery for a floor.
- Shower walls: tile must suit wet areas and go over a waterproofed backer, never ordinary drywall; joints, niches and benches are where leaks usually start.
- Shower floors: small tiles or mosaics follow the slope to the drain and add grout lines for grip, while large tiles need a linear drain or careful cuts to follow the slope.
- Slip resistance: glossy and polished surfaces turn slippery when wet or covered in snowmelt, so matte or textured finishes suit entrances, bathrooms and shower floors; ask for the maker's slip-resistance information for wet areas.
- Porches and unheated rooms: only tile approved for freeze-thaw exposure belongs there, since water absorbed by the tile can freeze and crack it.
Tile substrates and membranes: uncoupling membranes, backer board and shower waterproofing
Tile follows whatever it's bonded to. On a wood subfloor, the structure must be stiff enough for tile, not just for walking: a floor that gives slightly under carpet can crack grout and tile within a season. The tile and membrane makers' instructions set what the framing and panels must be, installers often add underlayment, and framing that's too weak is reinforced by a carpenter first.
An uncoupling membrane is a thin sheet laid between the subfloor or slab and the tile. It lets the base move slightly, with temperature and humidity or across a hairline crack in concrete, without passing that stress into the tile. It won't rescue a floor that flexes too much, but it's widely used over wood, heated floors and slabs, and some versions double as waterproofing.
In a shower, grout and most tile let moisture through, so the tile goes over a cement or foam backer covered by a continuous membrane, in sheets or brushed on as a liquid, lapped and sealed at every seam, corner, niche, valve and the drain. The parts should belong to one system the maker approves together, and careful installers flood-test the shower floor before tiling.
Tile layout, grout types and sealing: what a careful installation looks like
Before any mortar is mixed, a good installer plans the layout: where the first row starts, how cuts are balanced so thin slivers don't land at a doorway or along the most visible wall, and how joints line up with a tub, a counter or the next room. Large and rectangular tiles need extra care, since a slight bow or an uneven edge between neighbours, called lippage, shows in raking light. Movement joints filled with flexible sealant rather than grout go at inside corners, around the perimeter and where tile meets other materials.
Cement-based grout is the traditional choice, sanded for wider joints and unsanded for narrow ones; it's porous and usually benefits from a penetrating sealer once cured. Epoxy and other premixed grouts resist stains and moisture much better and generally need no sealer, but they're less forgiving to apply. Natural stone and some unglazed tile need their own sealer, sometimes before grouting so the grout doesn't stain the surface.
Heated floors under tile: laying the heating cable and who connects it
Tile and stone carry radiant heat well, and an electric heated floor is a popular addition in bathrooms, entrances and basements. The cable or mat goes down on the prepared floor, often inside a membrane made for it, and is embedded in mortar or self-levelling compound before tiling. The tile setter usually does this part and tests the cable before, during and after installation as the maker instructs, because a cable nicked by a trowel is very hard to reach once tile covers it.
Connecting the floor to a circuit, its required protection and a thermostat is electrical work for a licensed electrician, who also handles any permit or inspection required where you live. Decide early where the thermostat and floor sensor will go, leave unheated the spots where a vanity or toilet will sit if the maker says so, and keep the installation records for the warranty.
Silica dust when cutting tile: why pros cut wet and control the dust
Cutting, grinding and drilling tile, stone, concrete and cement-based products can release very fine dust containing crystalline silica. The Canadian Centre for Occupational Health and Safety (CCOHS) warns that breathed-in silica dust can damage the lungs and lists crystalline silica as a known cause of lung cancer; its guidance on stone fabrication adds silicosis, an incurable lung disease, and chronic obstructive pulmonary disease.
CCOHS recommends controlling dust at the source: wet methods while cutting and grinding, tools with local exhaust or HEPA vacuum attachments, and clean-up with a HEPA vacuum or water rather than dry sweeping or compressed air, with respiratory protection when those controls aren't enough. At home, that means a wet saw set up outdoors or in a ventilated area, dust extraction on grinders and the work area closed off from the rest of the house. Ask how the installer will handle it before work starts, especially if children or anyone with a lung condition live there.
Repairing cracked tile and grout, and when to redo the tile floor
A single tile cracked by a dropped pan can usually be replaced: the installer removes the grout around it, breaks it out without disturbing its neighbours, cleans the bed and sets a spare from the same batch. Crumbling or stained grout can be raked out and renewed without lifting tile, and failed sealant at a tub or shower base is cut out and redone, small jobs that keep water from getting behind the tile.
Cracks running in a line across several tiles, tiles that sound hollow when tapped, or grout that keeps cracking in the same spot point to a problem underneath: a floor that flexes, a moving slab crack or missing movement joints. New tiles won't hold until the cause is fixed, and when damage is widespread, redoing the floor over proper support or a membrane is often the lasting answer. In a shower, loose tiles, grout that stays dark and damp or a stain on the ceiling below mean water is already behind the tile, and the waterproofing has to be opened and checked.
Tile Installation: frequently asked questions
Can new tile go over old tile?
Sometimes, if the old tile is well bonded, flat and free of cracks, and the mortar maker allows it; the surface is cleaned and roughened or primed first. The added height has to clear doors, cabinets and appliances, and cracked or hollow-sounding tiles mean the old layer has to come out.
Is porcelain or ceramic better for a front entrance?
Usually porcelain, because it's denser and stands up better to grit and salty slush. Choose a matte or textured finish for grip when the floor is wet, and a colour-body tile so chips are less noticeable.
How soon can I walk on new tile or use a new shower?
It depends on the mortar, grout and membrane, which each have a drying or curing time in the maker's instructions, and on how warm the room is. Ask the installer for the schedule in writing, and don't shower or seal the grout before that time is up.
Do porcelain tiles need to be sealed?
Glazed ceramic and most porcelain don't, but cement-based grout usually does, as do natural stone and some unglazed or polished porcelain. The tile maker's care instructions say which applies to your product.
Sources
Written by the LokalMatch editorial team. Reviewed by Zubair Afzal on September 10, 2026. How we write and check our guides