Porcelain tile is dense, hard and nearly waterproof, which is exactly why it lasts and exactly why it is a little more demanding to install than ordinary ceramic. It needs the right thin-set, a diamond blade, full mortar coverage and a flat substrate, and its common large sizes make leveling more important. This step-by-step guide covers porcelain tile installation from substrate to first footsteps.
How do you install porcelain tile?
To install porcelain tile: prepare a flat, solid substrate; plan the layout; mix a mortar rated for porcelain; comb it with a notched trowel; back-butter larger tile; set each tile with clips and wedges to keep edges flush; let the mortar cure; remove the clips; then grout and clean.
- Prepare the substrate. Concrete should be clean and sound; wood floors need a stiff subfloor and an underlayment such as cement board or an uncoupling membrane. Check flatness with a straightedge.
- Lay out. Find the room’s center lines, dry-lay a row each way, and adjust so cuts at the walls are balanced.
- Mix mortar. Use a thin-set labeled for porcelain and mix only what you can use within its open time.
- Trowel and back-butter. Comb straight ridges; skim the back of tile 12 inches and larger.
- Set and level. Press each tile in with a slight slide, place leveling clips at its edges, set the next tile, and tighten wedges.
- Cure, remove clips, grout. Wait for the mortar to cure, knock off clip tops, then grout and clean.
Is porcelain tile difficult to install?
Porcelain tile is not difficult to install if you have the right tools, but it is less forgiving than soft ceramic. It is harder to cut, it needs a mortar made for dense tile, and its larger sizes demand a flatter substrate and better coverage. A careful DIYer can do it.
Most problems come from three shortcuts: using the wrong mortar, skipping substrate prep, and setting large tile without a leveling system. Avoid those and porcelain is no harder than any other tile. For tile 15 inches and longer, read large format tile installation as well.
What thin-set for porcelain tile?
Use a polymer-modified thin-set labeled for porcelain tile, and for large or heavy porcelain, one labeled for large and heavy tile. Porcelain absorbs almost no water, so it relies on the mortar’s polymers, not on soaking in, to bond well.
A modified thin-set has polymers added to improve bond and flexibility. An unmodified thin-set is plain cement, sand and water retention agents; some membranes and specific products call for unmodified mortar, so always follow the substrate or membrane maker’s instructions. Read the bag for tile type, size range and maximum bed thickness. Coverage should reach at least 80% in dry areas and 95% in wet areas and exteriors, per NTCA’s TileLetter.
How do you cut porcelain tile without chipping?
Cut porcelain without chipping by using a sharp diamond blade made for porcelain on a wet saw, feeding the tile slowly, supporting both sides of the cut, and cutting face-up. For straight cuts, a quality manual cutter with a fresh scoring wheel also works well.
A porcelain blade has a continuous or fine-segmented rim that leaves a cleaner edge than a general-purpose blade. Start slowly at the edge to avoid blowouts, keep the water flowing, and smooth sharp cut edges with a rubbing stone. Place cut edges at walls or under trim when possible. Holes for pipes are easiest with a diamond hole saw.
What grout joint for porcelain tile?
A 1/8 inch joint is the common grout joint for porcelain tile from 12×12 to large format when you want a narrow but visible grout line. Rectified porcelain can go to 1/16 inch where the tile maker allows; calibrated porcelain often needs 3/16 inch.
Check the tile maker’s minimum joint on the box. Next Level offers leveling clips for porcelain tile in 1/32, 1/16 and 1/8 inch, and the clip size chart matches clip to tile. For ceramic versus porcelain differences, see ceramic and porcelain tile spacers.
How do you keep porcelain tile level while it cures?
Keep porcelain tile level while it cures with a tile leveling system: clips under the edges and wedges on top hold neighboring tiles flush until the mortar hardens. Do not walk on the tile or disturb the clips until the mortar has cured.
As mortar cures, tile can settle unevenly, especially large porcelain resting on uneven ridges. Clips stop that drift. The Next Level tile leveling system is designed for ceramic and porcelain and uses reusable wedges, so the cost of leveling drops on every job after the first.
How long before you can walk on porcelain tile?
Wait until the mortar’s stated cure time for foot traffic before walking on new porcelain tile, which is printed on the bag and varies with product, temperature and humidity. Rapid-setting mortars allow traffic sooner. Grout has its own cure time, and grout sealer goes on later still.
Walking on tile too soon can shift it and break the bond. Remove leveling clips only after the mortar has cured; then grout, let the grout cure as its label directs, and apply a grout sealer if your grout calls for one.
Frequently asked questions
Can you lay porcelain tile over existing tile?
Sometimes, if the old tile is well bonded and flat, and the mortar is rated for that. Height at doors and transitions often rules it out.
Do you need to seal porcelain tile?
Porcelain itself rarely needs sealing; cement grout often does. Follow the grout maker’s instructions.
What is the best way to start a porcelain floor?
Start from a straight reference line near the room’s center, not from a wall that may be out of square.
Key terms
- Modified thin-set: cement mortar with polymers added for better bond and flexibility.
- Unmodified thin-set: cement mortar without added polymers, required by some membranes and methods.
- Porcelain blade: a diamond blade with a fine rim designed to cut dense porcelain cleanly.
- Polymer-modified mortar: mortar that contains latex or other polymers to improve bond strength.
- Cement board: a cement-based panel used as a tile substrate over wood framing.
- Grout sealer: a liquid applied to cured cement grout to reduce staining.
- Foot traffic wait time: how long the mortar maker says to wait before walking on new tile.
- Porcelain cutting: cutting dense porcelain with a wet saw or scoring cutter designed for it.
Sources
Laying porcelain soon? Next Level clips and reusable wedges ship nationwide, sold by quote. Request a quote for porcelain leveling clips with your tile size and square footage.