The following text and illustrations are designed to acquaint Habitat for Humanity volunteers, homeowners and workers with the necessary steps to complete the floor tiling process in Habitat homes. This document addresses two techniques of floor tiling: tiling with spacers and tiling without spacers. Volunteers and others who have never tiled will find tiling with spacers to be a simpler method, and TPFH recommends using spacers. However, we recognize that some people prefer not to use spacers, and have included directions for tiling with a grid system for that reason. There are benefits to using each method, but for volunteers unfamiliar with tiling, use of spacers is simpler.

This document covers only the setting of tile and assumes that the substrate has already been prepared to receive tile. Suitable substrates include clean concrete slabs, properly prepared backerboards, and double plywood floors. Illustrations and descriptions of suitable substrates for floor tile can be found at www.thetiledoctor.com.

NECESSARY TOOLS FOR TILING

Notched trowel (1/4”x1/4” or 1/4”x3/8”)
Margin trowel
Buckets for mixing
Knee pads
Drill motor
Paddle mixer
Chalk lines
Pencils
Straightedge
Mallet (if available)
Measuring tape
Door jam cutter (to cut tiles to slide underneath door jams)
Tile cutter
Wet saw (if available)
1/4” spacers (if using spacers)
Clear lacquer spray (if not using spacers)
Tile nippers
Grout float
Hydro sponges
Rubber gloves
Cheesecloth
Grout sealer

FLOOR TILING WITH SPACERS

The first technique is illustrated in Figure A. Note that two lines called “working lines” appear at the upper right section of the diagram. These lines are easily established by measuring out from one wall in two places the width of one or two tiles plus room for grout joints (usually ¼”) and pencil lines. These marks are then chalked in using a chalk line. This step is repeated on an adjacent perpendicular wall. The end result is two intersecting chalk lines near two long walls. These two lines should be checked to see if they are square by using a large framing square or the 3-4-5 Method near the end of this document.

SETTING THE TILE

Mix thinset mortar per the manufacturer’s recommendations and use your notched trowel to apply it to the floor. You want to “key” in the mortar by using the flat side of the trowel to evenly cover the floor space, scraping the thinset into the floor as you go. Keep in mind, you only want to apply thinset to a small area of the floor at a time so that your thinset does not dry too quickly as you set the tiles. TPFH recommends applying thinset to an area large enough to cover no more than four or six tiles at a time.

Once the mortar is evenly spread across your workspace and keyed into the floor, you want to use the notched edge of your trowel to comb the mortar out to a uniform thickness. To do this, you will need to hold the trowel at or near a 45 degree angle. The important thing here is the consistency of the angle throughout the stroke. This provides the uniform thickness.

Once the mortar is ready, begin to set the tiles against your working lines and work back from that point. Set four or six tiles at a time and use ¼” spacers to separate them from each other. Use a mallet to gently beat the tiles into place and ensure good coverage of thinset (minimum 80%) on the back of the tile. Pull up several tiles in the starting courses to ensure good coverage. Align the tiles with the working lines and use a six-foot straightedge to ensure that the tiles stay straight. Use a margin trowel and sponge to remove any excess thinset from the joints (spaces between tiles) that may ooze out. This small step will save time later in the grouting process.

Repeat this process on successive courses of tile using the spacers to keep the tiles in place and use the straightedge to keep the tiles in line. Be sure to plan your progress so that you don’t tile yourself into a corner.

You may need to cut some tiles for them to fit into your floor plan. For simple and straight cuts, use the tile cutter to score and snap your tile. For a more complicated cut, such as a circular design to go around a toilet flange, you will need to use a wet saw or circular saw to shape the tile.

Also, as you proceed, check the corners where the tiles meet and ensure that there is not any excess lippage or height difference from tile to tile. If one is high, then tap it down. If one is low, pull it up and add a little thinset. When the tiling is complete, wait for the thinset to cure appropriately then grout. Remember, all spacers must be removed after the thinset has cured prior to grouting.

Mix your grout per the manufacturer’s recommendations and allow it to stand or slake for fifteen minutes prior to use. Force the grout into the joints using a laminated grout float held at or near at 45° angle. Slide the same grout float over the joints to remove excess grout. Be careful not to dig the edge of the float into the joints, but to instead move the float at an angle to the joints so only excess material is removed. Allow the grout to firm up per the manufacturer’s recommendations. Use a hydro sponge, moistened and then wrung almost completely dry, to wipe over the joints and remove excess grout. This step is called “tooling” the joints and will eliminate pinholes, voids, and high or low spots.

Finished joints should be uniform and consistent in appearance. One final wipe diagonally across the tile with a nearly dry sponge, rinsing after each pass, will clean the tiles adequately. Allow the grout to haze over and then carefully polish off the haze with cheesecloth. Try to avoid digging into the fresh joints. Allow the grout to cure per the manufacturer’s recommendations and seal the grout after a minimum of 48 hours.

FLOOR TILING WITHOUT SPACERS

In figure B, you will note two very dark lines near the center of the tiled space. These lines are similar in that they are established by measuring out from two perpendicular walls the distance of several tiles plus grout joints to the approximate center of the room. Once the central lines are established, they are checked to make sure they are square by using a large framing square or 3-4-5 Method (the 3-4-5 Method is preferred for this technique).

From these lines, you will measure and chalk line in grid boxes which equal four or more tiles (two rows of two) plus the required grout joint spacing (the lighter lines in the illustration). The boxes can be up to approximately 36” but are more manageable in the 24” range. The box size is simple to determine. Simply lay out four or more tiles on the floor, add the grout joint spacing (usually 1/4” each) and measure what the outside dimension needs to be. For example, if you had 12” X 12” tiles and you wanted a ¼” grout joint, your boxes would need to measure 24 ½” X 24 ½”.

Once the whole floor area is chalked out with the appropriate sized boxes, use a clear laquer spray on each line to “permanize” the lines so that they will not wear away during the tiling process.

THE 3-4-5 METHOD

For the 3-4-5 Method to work, simply measure down one of the main or room square lines three feet from where the lines intersect and make a pencil mark. Repeat this on the opposing line you wish to check for square but this time makes your mark at four feet. Now measure between those marks at a diagonal. If the measurement is five feet long, then the lines are square to one another. If they are not, adjust them by removing the chalk with a damp sponge.

This method also works in multiples of 3-4-5 for larger rooms. (IE: 6-8-10/12-16-20, ETC).

Set the floor tile in the manner described above and without covering your working lines with thinset mortar. After beating the tiles in with a mallet, align the tiles with the chalk lines in the center of the grout joints or orient the tiles to one side of the grid box. If your choice is to orient the tiles, you must always orient to the same sides of the box throughout the floor.

The advantage of this technique is that it eliminates the use of spacers and offers the tile installer the ability to move around obstacles and corners. In addition, many of the necessary cuts to tiles can be made ahead of time, and the entire floor layout can be viewed prior to its installation.

This has been a very quick description on two types of tiling techniques. Much more information is available at www.thetiledoctor.com.