Bathroom Floor Tile Materials List: Tile, Thinset, Grout, Backer
A 5 × 8 ft bathroom floor (40 ft²) in 12 × 12 inch tiles takes 44 tiles (5 boxes of 10, with 10% extra), 1 bag of thinset, about 3.1 lb of grout, and 3 sheets of cement board if you are laying over a wood subfloor. This is the whole list, with what each number assumes.
The materials list
| What to buy | How much | How we worked it out |
|---|---|---|
| Floor tile (12 × 12 in) | 44 tiles, 5 boxes of 10 | Tile calculator: 40 ft² plus 10% for cuts, with a 1/8 in joint. Buy one extra box for future repairs and keep the lot number |
| Thinset mortar (50 lb) | 1 bag | With a 1/4 × 3/8 in notched trowel, a bag covers about 65 ft². A flat, clean floor is what makes it go that far |
| Grout | 3.1 lb, so one 10 lb bag | Sanded grout for joints 1/8 in and wider. This includes 20% for waste. Buy a little extra: a second batch may not match the color |
| Cement board or uncoupling membrane | 3 sheets of 3 × 5 ft | Over a wood subfloor, tile needs a stable base. Check what your tile and thinset instructions require |
| Board screws and mesh tape | 1 box of screws, 1 roll of tape | For cement board seams, and the thinset to bed the tape |
| Tile spacers (1/8 in) | 1 bag | Keep the joints even |
| Grout sealer (optional) | 1 bottle | Cement-based grout is porous. Seal it once it has cured, as the label says |
| Transition strip | 1 per doorway | Where the tile meets another floor |
| Tools | Trowel, float, sponges, wet saw or tile cutter, mixing bucket | A wet saw can be rented. A manual cutter is enough for straight cuts on tile up to about 12 in |
Materials for other floor sizes
12 × 12 in tiles, 1/8 in joints, 3/8 in thick, 10% waste, 10 tiles per box and thinset at 65 ft² a bag:
| Floor area | Tiles | Boxes (10) | Thinset bags | Grout |
|---|---|---|---|---|
| 25 ft² | 27 | 3 | 1 | 2.0 lb |
| 40 ft² | 44 | 5 | 1 | 3.1 lb |
| 60 ft² | 65 | 7 | 1 | 4.7 lb |
| 80 ft² | 87 | 9 | 2 | 6.3 lb |
| 100 ft² | 108 | 11 | 2 | 7.8 lb |
Large tiles change the picture: the same floor in 24 × 24 inch tiles with 3/16 in joints and 15% waste takes 12 tiles (3 boxes of 4) and 1 bag of thinset with a bigger trowel, and they need a much flatter floor. See the tile, grout and thinset guide.
Before you start
- Check that the floor is flat. Large tiles show every dip, and thinset cannot fill a big one. A self-leveling underlayment fixes it.
- Do a dry layout before you spread any thinset, and shift the starting line so the edge tiles are not thin slivers.
- Take out the toilet and the baseboards if the tile will run under them, and plan for the door to clear the new floor height.
- Let the thinset and grout cure for the time on the packaging before walking on the floor or using the shower.
How the job goes
- Prepare the subfloor: clean, flat, and with cement board or a membrane screwed or bonded down as required.
- Mark the layout lines, spread thinset with the notched side of the trowel, and press each tile in with a slight twist.
- Use spacers, check with a level, and clean the thinset off the surface as you go.
- After the thinset has cured, grout the joints with a rubber float, wipe the haze with a damp sponge, and polish when it dries.
- Seal the grout if required, and caulk (do not grout) where the floor meets the tub or the walls.
Estimates only. The instructions on your tile, thinset and grout always win.
Frequently asked questions
How many tiles do I need for a 5x8 bathroom floor?
40 tiles of 12 × 12 inches cover the 40 ft² exactly, and 44 with 10% for cuts and breakage, which is 5 boxes of 10.
How much thinset and grout does a bathroom floor need?
About 1 bag of thinset (50 lb, with a 1/4 × 3/8 inch trowel) and roughly 3.1 lb of grout, so a 10 lb bag is enough for 12 × 12 inch tiles with 1/8 inch joints.
Do I need cement board under bathroom tile?
Over a wood subfloor, tile usually needs a stable backer such as cement board or an uncoupling membrane. For this floor that is about 3 sheets of 3 × 5 ft cement board. Follow the instructions for your tile and thinset.
How much extra tile should I buy?
Ten percent for a straight layout, 15% for diagonal or large-format tile. Keep a spare box and the lot number, because tile is hard to match later.
More guides
Tools & materials for this project
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Estimates only. Quantities depend on your materials, site and supplier. Confirm important numbers before you order, and follow local building codes for anything structural.