Installing Floor Tile: Estimating the Cost

Types of Subflooring
There are some basic things you need to consider when adding up the cost of installing floor tile. First, what type of subfloor do you have? The subfloor is the surface below whatever you are walking on. Usually it will be concrete (known as a slab) or wood slats or plywood raised above the ground (raised foundation). Both types require some very specific materials and techniques in order to get a tile job that both looks good and will stand up under use. We’re going to cover raised foundations in this article.

Raised Foundation Subfloor
The problem with installing tile over wood is that wood is flexible and bends, tile does not. If you don’t properly prep the floor, your ceramic tile will pop loose as the floor gives and the temperature changes. In order to prevent this, we will need to install a solid surface over the subfloor. It is often a good idea to start with plywood, especially if the subflooring is uneven or cracked. Cut the plywood to fit around corners and fixtures and screw it to the subfloor every six to eight inches.

Backer Board
Over the top of the plywood comes the backer board. Two brands you are likely to see are Wonder Board and Hardy Backer. Backer board is screwed to the subfloor or plywood with special screws, so don’t forget to allow for several boxes of these.

Using Thinset Mortar and Tile Spacers
To attach tile to the backer board you will use thinset mortar. (Note: If you want an even stronger floor, add a layer of thinset between the backer board and the plywood before you screw it down.) It comes white or gray, in powder form or premixed. Premixed is much easier for small tile jobs, but it gets expensive if you are laying a large amount of tile. Rubber spacers are used between the tiles to keep your grout lines even.

Tile Grouting
After the tile is down and cured, the ceramic tile grout is applied. Tile grout looks like fine sand and is mixed with water and pressed in between the tiles. After all of this has set up and cured, you may want or need to seal the tile and/or the ceramic tile grout. Some sealer comes in a spray can and others are applied with a rag.

Supplies Needed for Laying Floor Tile
We’re not done yet. There are several tools that you will need to complete this job. If you don’t own them, you will have to borrow, buy or rent them to get the job done. You will need a saw to cut plywood, a screw gun or drill to attach plywood and backer board and a scoring tool to cut backer board. A notched trowel is used to spread thinset (the notches are square, not triangular and their size depends on how big your tile is.) You will need the use of a tile saw as tile must be cut around cabinets, fixtures and fit to the walls. Renting a saw is far better than buying it as they are quite expensive. A grout float and spacer remover rounds out the tool list. These last two are fairly inexpensive, so buying them won’t be too bad.

Supply List for Floor Tile Installation
This supply list may vary depending on the specific type of tile and grout you’re installing, as well as the type of subfloor you have:

• Ceramic Tiles
• Tile Saw (These can be purchased or rented)
• Plywood (To repair/replace damages subfloor)
• Wood Saw (If subfloor repair is needed)
• Screw Gun or Electric Drill
• Wood screws, Backer Board Screws
• Thinset Mortar
• Rubber Tile Spacers
• Tile Grout
• Scoring Tool
• Notched Trowel (Square notches for thinset application)
• Grout Float
• Spacer Remover
• Grout and Tile Sealer
• Sealer Applicator
• Large Bucket (For mixing thinset and/or tile grout)

Often times, large home improvement centers offer both classes and tool rental, as well as help with materials selection. Don’t hesitate to ask questions and take notes. Installing beautiful new ceramic floor tiles can be rewarding, while adding value to your home.