Interior Floor Tile Installation
How to Tile Interior Floors – Installation Tutorial
What You’ll Need for this Tile Installation Project
- 1/2″ backerboard
- Thinset mortar
- Joint Tape
- Utility knife
- Pry bar
- ¼” X 3/8” rounded notched trowel
- Mallet and beating block
- 1 ¼” screws
- Grouting tools
Installing Tile on Interior Floors
In the following photos, we will see an upstairs bathroom remodeled with the installation of a polished marble floor placed over ½” backerboard.
The original bathroom floor was carpeted. The carpet was installed over an OSB sub-floor with joists spaced 16” on center (based upon examinations of the ceiling in the room below.) This made it suitable for using a backerboard to install the floor tile.
If you find yourself in a similar situation, you will first want to remove the baseboards. Here we did so by scoring the paint with a utility knife then prying the baseboard off with a pry bar.
Next, cut the carpet where the tile and carpet will eventually meet. Generally in doorways, the ceramic tile and carpet will meet in the middle of the door so that the joint cannot be seen when the door is closed.
In an archway such as this, the joint will be in the approximate middle of the floor directly beneath the arch.
In the bathroom, remove the padding and tack strip from the floor area. The tack strip is removed with a pry-bar and the padding simply by pulling it loose.
In this case, the padding was only stapled to the wood sub-floor. The staples were removed with a pair of pliers.
If the padding had been glued down, it would have been necessary to scrape the glue and padding remnant with a scraping tool.
Your goal here is to make the wood sub-floor as flat as possible.
In this case, the sub-floor is sound and on plane. We only need to re-drive the floor fasteners that were’t driven flush with the floor surface by the original trades.
These fasteners, with square head drives, were driven flush prior to proceeding with the backerboard installation.
Next, you’ll want to cut the doorjamb trim to allow the backerboard and tile to slip under the wood trim easing the installation and creating a more professional appearance.
Next, you’ll want to take measurements and cut the backerboard to fit into the floor areas allowing 1/8”-1/4” gaps between sheets and ¼” at all perimeter joints.
Here, we arranged the backerboard perpendicular to the sub-floor making the backerboard parallel to the flooring joists.
Backerboard joints should be staggered so four corners do not meet together.
For cutting the toilet receptor hole, the drill and punch method works well.
In this case, we used a hand grinder with a dry cut off blade.
Once all the panels are cut and properly fitted onto the sub-floor, the panels are lifted up and a bed of dry or latex modified thinset is placed onto the sub floor.
The thinset is “keyed in” using the flat side of the trowel then combed out to a consistent depth using the notched side. In this case a ¼” X 3/8” rounded notched trowel was used at a 45° angle to ensure that the panel comes to rest on the sub-floor fully supported on its entire underside.
Next the panel is beaten in with a mallet and beating block. Note how the panels are staggered and that no four corners are allowed to meet at one spot.
Next the panels are screwed down on 6”-8” centers along the perimeter and in the field with the recommended 1 ¼” screws. The screws should not come closer than 2” to the edge of the board. Be sure to drive the screws flush with the panel surface. However, use caution to not overdrive the screw as the strength in this type of board is at the surface mesh.
The process of fastening the boards continues till the last panel is adhered and screwed.
The Manufacturer of this backerboard requires the filling of the backerboard joints during the tiling process with the same setting mortar used to set the tiles. The Manufacturer does not require the filling and taping of the joints with mesh tape as other backerboard Manufacturers do.
The filling and taping of joints is an extra precaution used in this job and may well be over building. The result is a more monolithic floor. The procedure is to fill the joint, imbed the alkali resistant tape, and smooth the joint with thinset feathering it out over the joint.
The procedure of filling and taping the joints does require that the joints have time to cure before the application of tile. If you plan on tiling the floor soon after the panels are set, then a fast setting thinset may be used in the filling and taping process to speed up the job. Be sure to check with the Manufacturer concerning the products you plan to use.
Next the layout process starts. In this case, we decided to have full tile at the entrance and at the edge of the combination shower and tub. This provided a nearly full tile across the room where the double sink cabinets were. Most of the visible cuts appeared to be full tile.
The process was simple. Full tile was laid out from the shower face and room entrance and measurements indicating the full tile placement were taken. Two working lines were established down the length of the room and one perpendicular to the first line. A framing square verified that the line were square to one another then verified with the 3-4-5 method.
Next the entire floor area was measured and grids were chalk lined in establishing where all the tiles will be set. Each “box” or grid has room for four tiles and grout joints in the center and on two sides. This is known as the grid method seen in the “estimating/layout-floors” section.
The final step once you are sure the lines are exactly where you want them is to “permanize” the lines with clear lacquer spray.
Next pick up the dry set tile and begin the tiling process by “keying in” the thinset onto the backerboard surface using the flat side of the trowel. Follow the “keying in” process by combing out the thinset to a uniform depth using the notched side held at a consistent 45°angle. Be sure to apply the thinset inside the working lines without obscuring them.
Be sure to clean the edges next to adjacent tile of excess thinset with a margin trowel to prevent too much thinset “squeeze” in the grout joints.When the tiles are placed within the grids, always orient the tiles to the same lines in every grid. The four tiles will always meet two of the lines directly while allowing grout joint space on the other side of the grid.To illustrate this concept, let’s say the marble tile is 12” exactly and you want 1/16” joints. Each grid would measure 24 1/8”. This allows a 1/16” joint between the tiles and a 1/16” joint at two sides of the grid.
The final step in setting the tile is carefully beating in the tile with a beating block and rubber mallet. This will ensure the proper coverage of thinset and will minimize lippage. Be sure to beat in on the joints and the four corners where the tile meets each other. Finally realign the tiles within the grid and move ion to the next grids.
After beat in, be sure to clean the tile surface with your tile sponge and clean out any excess thinset from the grout joints. This step will save you a lot of time during the grouting process.
The tiling process continues until the floor is completely tiled. The floor is allowed to cure according top the Manufacturers specs and the grouting process begins.
Assemble your grouting tools.
Mix the intended grout per the manufacturers specs.
In the case of polished marble, non-sanded grout should be used so that the polished surface will not be scratched during the process.
Mix the grout and remove the lumps by forcing the grout against the bucket side with the margin trowel until the grout is completely smooth and the consistency of a thin sour cream.
Do not forget to allow the grout to stand or “slake” for fifteen minutes.
Use a grout sponge nearly wrung dry of water and tool the joints applying as little pressure as possible diagonally across the tile joints. The point here is to make the joint presentable without digging the grout out of the joint.
Do a final wipe of the tile joints diagonally to remove the excess grout. The joints should be smooth, uniform, and free from voids or pinholes.
When non-sanded grout is used in very deep marble joints, it is sometimes necessary to refill the joints once the water leaves the original grout in the joint. The procedure is the same.
Next the dissimilar surface joints are filled with a sealant that matches the grout color.
The perimeter joints are left open to be covered by base molding and the job is finished. Beautiful, wouldn’t you agree?