Project Guide

How to Install a Tile Floor

Choose Tiles & Prep the Space
Man sweeping up subfloor before installing tile.

Learning how to lay floor tiles is a fairly simple process, but it's something that takes a bit of preparation. Tile comes in a variety of styles, colors and patterns. Use these tips to get started: 

  • Find out all you can about the types of tiles available before you decide. 
  • Your subfloor should be able to support tile, mortar, grout and furniture when the project is complete. It should be clean, dry and flat. 
  • Inspect your subfloor and take care of any dips, cracks or uneven places that will cause your tile to buckle or not install properly. 
  • Measure the area to ensure you have enough tile. If you decide to replace your floor, use a water-resistant backer board. 

Tip: Research how to prepare the subfloor before you begin your DIY tile floor project.

Gather Tools & Materials
A trowel, spacers and level placed next to work gloves.

When it comes to installing a tile floor, you will need a rubber mallet, spacers, a level, a tile trowel and Thin-Set or another type of mortar. Thin-Set is cement-based, but some mortars are labeled as “non-modified” and require a latex polymer admixture that will improve the performance of the mortar and increase bond strength. Make sure to get the trowel size, mortar type and other tile setting materials such as spacers that are recommended by your tile’s manufacturer. 

For cutting tiles, there are several tool options: a manual snap cutter, an electric wet saw and a tile nipper. The manual cutter is generally used for smaller jobs. But for jobs that require cutting a large number of tiles, a wet saw is best. For specialty cuts around things like plumbing fixtures, pipes and round corners, a tile nipper comes in handy.

Be sure to wear safety glasses and rubber gloves when mixing and applying mortar or dealing with other flooring tools. Wear knee pads to evenly distribute your body weight and protect your knees. When determining how to lay floor tiles in an area that will adjoin with a different kind of flooring, like carpet or hardwood, include a threshold transition in your list of supplies.

Use a Layout
Person putting spacers between blue and white tiles.

Another important thing to know about how to lay tile is the fact that you need to draw a layout of your finished tile design on your floor. The layout’s lines show you where to start laying floor tiles and are arranged so the floor tiles are evenly centered in the room. Layout lines must be square, otherwise you will end up with odd-shaped tiles at the walls. 

  • The best way to ensure square lines is to make a floor plan by drawing the walls of the room as accurately as possible on a sheet of grid paper. Be sure to include doorways and floor obstructions such as cabinets and fixtures as well as any tile edging or trim.
  • Find the center point of the room by measuring the four walls for their midpoints. 
  • Snap two chalk lines, one from the midpoints of two opposite walls, and another from the midpoints of the other two walls. Where they intersect will be the room’s center point. 
  • Check that the chalk lines are square by marking points 3 feet on one chalk line and 4 feet on a perpendicular chalk line starting at the intersection. 
  • Measure the diagonal space between each of these two points. If the distance between the two is exactly 5 feet, the lines are square. If the lines are not square, the tiles will be off center and the room might look unbalanced. If the room is not square – which is common – you will need to make adjustments to the position of one line, and then square the other line using the 3-4-5 procedure mentioned above.

Tip: Make a floor plan and mark the dimensions of your scale; for example, 1-inch gridline = 1 foot of floor space. 

Test the Layout
Someone measuring tile and floor.

Tiling a floor starts with testing the layout you’ve designed. 

  • Start by laying a single half row of floor tiles in both directions without mortar, starting at the center point and working outward. Some tiles have directional arrows on the back. You must keep these arrows pointing in the same direction as you are laying floor tiles to ensure pattern alignment. 
  • Insert spacers between the tiles. 
  • Stop when there is not enough room for a full tile. If the space at the end of either row is smaller than 1/3 of a tile, adjust your chalk lines so half the tiles appear on both sides of the room. Since you started in the center, 1/3 of a tile on one end means you’d have two-thirds of a tile on the other end and your room will look off-center.

Tip: Pull tiles from different boxes and mix them as you go, so the tonal differences between different batches of tile are less noticeable.

Prepare the Thin-Set
Person mixing grout in an orange Homer bucket.

Thin-Set mortar is a common bonding agent used to attach tiles to the backer board or concrete subfloor. It is made of cement and fine sand and will need to be mixed with water if bought dry. Mix your Thin-Set in a large bucket using a drill with a mixing paddle, following the package directions. Keep in mind:

  • Mortars cannot be used immediately and must be allowed to stand for five to 10 minutes after mixing. This is known as “slake time” and allows the chemicals in the mortar to fully activate. 
  • Take care not to mix too large a batch of Thin-Set. It has a limited working life, and if you’ve mixed too much, it will start to harden before you’ve had a chance to use all of it. 
  • Clean the mixing paddle promptly after use so the mortar does not harden on it. 
  • An important thing to remember about how to lay porcelain tile is that it must be installed using a polymer-modified Thin-Set to achieve the right bond between the tile and the substrate. 
  • For wood subfloors where a backer board was installed, be sure to moisten the backer board by misting with a spray bottle filled with water before spreading the Thin-Set. Spray the backer board as you work, otherwise the backer board will soak up water from the mortar, causing it to dry too rapidly. This will impact how well your tiles adhere to the subfloor.

Tip: Do not add water after the Thin-Set begins to harden. It weakens the cement and severely affects the bonding between the tile and the backer board. 

Use a Tile Trowel
Person applying grout or Thin-Set with a trowel.

Tile trowels have both a smooth edge and a notched edge. The notches are called teeth. The depth and width of the teeth of your trowel depends on the type and size of the tile. The size of the notch determines how much Thin-Set is left on the floor under the tile. Typically, the larger the tile, the larger the notch should be. 

  • Use your trowel to scoop out a generous amount of mortar from your mix bucket. 
  • Starting in one quadrant at the center point of the room where your chalk lines intersect, begin spreading the Thin-Set with the flat side of the trowel and press it into the backer board at roughly a 45-degree angle. This will ensure the mortar fully adheres to the backer board.

Tip: Follow the tile manufacturer’s recommendations when choosing a trowel.

Test the Mortar
Man adding spacers between round tiles.

At the beginning of your tile floor installation, always do a test to ensure the consistency of the mortar is appropriate. 

  • Put the first test tile onto the Thin-Set bed. Lay the tile flat and then with mild pressure, slide the tile 1/4-inch back against the Thin-Set ridges, then slide it back into place. 
  • Pull the tile up and check the back of the tile. It should be completely covered with Thin-Set. If you have areas on your test tile that are not covered with mortar, it means you did not mix the mortar properly, did not spread the mortar evenly or waited too long to set your first tile and the mortar started to dry. It may also mean you didn’t evenly and firmly press the tile into the mortar. Correct as necessary before you proceed.
  • Once you’ve confirmed you have the right consistency in your mortar, re-lay your first tile, ensuring it lines up with the chalk lines at the center and that it is fully pressed back into the mortar. 
  • Place two spacers along the side where you will add a tile, one on each end. Spacers are used to easily and quickly ensure equal spacing between tiles. Always position your spacers so they stick up and out. A common mistake is to lay them on their side in the corners where four tiles meet. If you do this, they become embedded in the mortar and can be hard to remove. 
  • Set your second tile by aligning the edges and corners, hinging it down and slightly twisting it back and forth.
Apply Mortar in Sections
Man smoothing Thin-Set with a trowel.

If this is your first time figuring out how to install tile floor, you may only want to apply enough mortar for one or two tiles at a time. 

  • Comb the Thin-Set using the notched side of your trowel, holding it at a 45-degree angle to the floor and lightly pushing the trowel teeth to the floor. 
  • Make sure you comb the Thin-Set in one direction. Avoid circular or swirling patterns. The combed channels will flatten out and compress when the tile is placed, ensuring the proper amount of mortar is present beneath the tile. 
  • Use a small, thin trowel to remove a small amount around the edges of your tiles as you go. Do not allow the Thin-Set to skim over or start drying as you go. If it does, remove it and apply a new layer of Thin-Set. 
  • As you lay each tile, check them for dirt or dust. Wipe them clean if needed. The dust can affect how effectively the tiles adhere to the mortar.

Tip: When installing floor tiles, always follow the chalk lines in your floor plan to ensure you're laying tiles in a straight line.

Level Tiles
Man leveling rows of tile using a mallet and wood board.

After installing three or four tiles, make sure they are level.

  • Place a 2 x 4 on top and tap lightly with a rubber mallet. This will level the tiles and embed them firmly in the mortar. 
  • Continue spreading mortar and setting additional tiles.
  • Throughout the process, use a damp sponge to clean off any mortar that ends up on top of the tiles. Do not let it dry. Once dry, mortar on the finished floor is extremely hard to remove. 
  • Check your alignment by stepping back every so often and looking down the tile edges to be sure the lines are straight. This should be done often, before the mortar starts to dry and harden. 
  • If you find alignment issues while the mortar is still wet, you can straighten them before continuing.
Finish Laying All Tiles
Person placing tile near a wall.

Finish laying tiles in your first quadrant. You’ll then be left with the space between those tiles and the wall where cut tiles are required. Finish laying all full tiles in your other three quadrants and let the mortar harden. 

Different mortars have different curing times, but most require you to stay off the tile for 24 hours. If you need to take a break when installing floor tiles, always scrape up any mortar overlapping into an area you are about to tile. If left to dry, it will affect how well those new tiles adhere when you return to work those areas.

Tip: Plan your flooring installation so that you have an exit without stepping on any tiles before the Thin-Set hardens in about 24 hours. 

How to Measure Tile
Man measuring tile.

Cutting tiles so they fit into the space left along the wall starts with measuring. 

  • Measure where to cut a tile by placing the tile to be cut directly on top of the next full tile near the wall. 
  • Place the two tiles upright against the wall. This will leave an expansion gap between the tiles and the wall that will allow the floor to expand without causing cracks. It will also account for the space needed for the grout line.  
  • Place a fourth tile against those two tiles and on top of the tile to be cut.  
  • Trace along the edge of the fourth tile with a marker to draw a line on the first tile. This is where you will make your cut. 
  • Lay out, mark and cut small groups of tile at a time and leave them in the space where they will be installed. 

Tip: Install cut tiles in small groups to avoid mixing too much mortar and risking drying it out before you can use it all. 

How to Cut Tile
Man cutting tile.

Important rules when it comes to how to cut tile is to always measure twice before you cut, use the right tool for the job, use the tool properly and wear safety goggles.

  • To cut a curve, mark the cutting line, then cut away bits of tile with  tile nippers. Smooth the cut edge with an abrasive stone. 
  • To use the manual snap cutter, align the cutting wheel with the cut line you made with your china marker. Raise the pressing bar, and push the cutting wheel away from you using moderate pressure. This will score the tile. Lift the cutting wheel, lower the pressing tee and strike the handle to snap the tile.
  • When using the wet saw, adjust the fence or guide so the cut mark lines up with the blade. Hold the tile with both hands and advance the tile into the blade, guided by the fence. Cut slowly to avoid chipping the tile. Change the tile saw blades when cuts are not clean. Be aware that wet saws splash water and tile residue during operation. 

Tip: When tiling with natural stone such as porcelain floor tile, always use a wet saw to prevent it from breaking or chipping.

Apply the Grout
Someone grouting a blue and white tile floor.

Once your tile floor is complete, it's time to apply the grout. Grout fills the spaces between the tiles. Like paint, grout can come in a variety of color options that match or complement your tile. 

  • Before grouting, remove all of your tile spacers. Leaving the spacers in place and grouting over them will compromise the integrity of the grout. 
  • Protect baseboards, trim and neighboring floors with painter’s tape.
  •  Mix grout according to package directions.
  • After the grout is ready, spread it in sweeping arcs with the rubber grout float held at a shallow angle. 
  • Apply at a 45-degree angle to the spaces between tiles to prevent the float from pressing into the spaces and creating uneven grout surfaces. 
  • Press grout into the joints, filling them completely. Focus on small 4-by-4-foot sections.
  • After the grout is spread, remove the excess with a grout float held at a 45-degree angle. Work diagonally across the joints to avoid dipping into the joints. 
  • Mist the grout twice a day for three days to slowly cure it. Do not walk over the surface for eight to 12 hours.

Be mindful that there are several types of grout available: PolyBlend, in both sanded and non-sanded; Fusion Pro, a single-component grout that never needs to be sealed; Simple pre-mixed, a no-mix alternative to traditional grout; and Epoxy. Different grouts require different methods. For example, almost all cement grouts have latex polymer in the powder mix; others require a latex polymer admixture. A cement grout will set in about five to 15 minutes and have a putty-like consistency. Once the cement grout is mixed, let it stand for 10 minutes before applying.


Tip: For joints 1/8-inch to 1/2-inch, use sanded grout. For joints up to 1/8-inch, use non-sanded grout. Follow the tile manufacturer’s recommendations. 

Clean Excess Grout From Tiles
Person cleaning excess grout from tiles with sponge.

When tiling a floor, be careful to remove excess grout promptly to avoid grout haze. Grout haze happens when grout dries on a tile, dulling the finish. 

  • Take a damp sponge and make light passes across the tiles diagonally to clean off the excess grout. 
  • As soon as one section is complete, wring the sponge until no water drips from it before cleaning. Excess water can affect the consistency of the grout. 
  • Use both edges of each side of the sponge. Be careful not to press the sponge into the gaps. The drier the grout is on the tile surface, the harder it is to remove. 
  • Do as many passes as needed. The tiles won’t be clean on the first pass so be patient.
  • Rinse the sponge frequently in clean water and change out the water frequently, too. The cleaner the water, the more effectively it will remove the grout from the surface of your tiles. 
  • Remove any remaining grout haze by using an old T-shirt or cheesecloth. If you have trouble, try adding a grout haze remover solution. 
  • Try to remove all of the haze before it dries completely and becomes harder to remove.

Seal the Grout
Person sealing grout using a small brush.

Sealing your grout is essential to keeping grout lines clean and looking like new. Grout sealer provides unsurpassed, invisible protection for grout. Sealers help prevent stains and keep mildew and mold from growing into the grout. 

  • Choose a sealer with a built-in applicator or pick up a grout sealer application bottle. You can also use a grout additive such as StainBlocker that provides stain resistance during the curing process.
  • Wipe up any excess sealer within 10 minutes. If you’re using glazed tile, be extra careful to only seal the grout.
  • Follow the manufacturer’s instructions on when to apply your sealer. In most cases, you’ll want to first allow the grout to cure for about three days.

Tip: Expect your grout sealer to last an average of one to two years before needing to reapply it. If you drop water on existing grout and it seems to soak in, it’s time to reseal.

Install Thresholds and Baseboards
Dog bowl resting on finished tile floor.
  • To finish your project, remove the painter’s tape from any protected surfaces. 
  • Cover the 1/4-inch expansion gap left along the walls. You can do this with either matching bullnose tile trim or wood quarter-round moulding. 
  • Add any desired thresholds between your tiled floor and neighboring floors. 
  • With that, your tile project is complete, and you have successfully learned how to install tile flooring.

Now that you know how to tile a floor, creating a beautiful new room is as simple as picking your tile, gathering your tools and taking your time. When determining how much material you need for your DIY tile floor, don't guesstimate, calculate. Know exactly how much you need with our project calculators