Tile waste
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Waste is the tile you cut and cannot use, plus breakage, plus the pieces that would be a sliver against a wall. A straight grid against the long walls throws away the least. A diagonal cuts almost every perimeter piece. A herringbone cuts both ends of a rectangle on a changing angle. A large tile turns one bad cut into a large scrap. The percent is a stand-in for that layout. It is not a measurement of the offcuts.
What the opened guides actually say
BuildDirect’s tile and stone installation guide says to order 10 to 15 percent more than the measured area for cuts and breakage, and that diagonal, herringbone, and other patterned layouts may require more. It also says to keep leftover tile for repairs. La Tuilerie’s renovation guide says a typical loss for square or rectangular tiles is 10 percent, and shaped layouts such as herringbone or diagonal should plan on 15 to 20 percent. It adds that large formats, and it names 24 by 48 and 48 by 48, can need still more, especially in a small space, without giving that third case its own number.
Novoceram’s laying notes are tighter on a straight joint: add 5 to 7 percent. A staggered joint is about 10 to 12 percent. A diagonal joint is 15 percent. Their worked room is 25 square meters of 45 by 45 tile in a straight joint, written as 7 percent waste plus a separate 5 percent reserve, about 28 square meters. Three manufacturers, three bands. None of them is the TCNA Handbook. BuildDirect says installations should follow the TCNA Handbook and ANSI A108, and that product instructions prevail when they differ. The handbook itself was not opened.
| Layout | What was opened | This site starts at |
|---|---|---|
| Straight | BuildDirect 10–15%. La Tuilerie 10% for square or rectangular. Novoceram 5–7% for a straight joint. | 10% on the tile and flooring calculators. |
| Diagonal | La Tuilerie 15–20% with herringbone. Novoceram 15% for a diagonal joint. BuildDirect says patterned layouts may need more than 10–15%. | 15%. |
| Herringbone | La Tuilerie groups it with diagonal at 15–20%. BuildDirect names it as a pattern that may need more. | 20% on the flooring calculator. The tile calculator has no herringbone preset. |
| Large format | La Tuilerie: higher losses, especially in a small room. No single percent. BuildDirect uses 15 inches on an edge for flatness, not for a waste number. | No preset. Raise the field. |
The same floor, two percents
Leave the tile calculator at 10 feet by 10 feet, tile 12 by 12 inches, joint 0.125 inch. Tiles read 97.95 either way, because waste is applied after the module count. Straight, 10 percent, orders 108 tiles. With waste reads 110.00 square feet. Boxes read 11 at the 10 square foot planning coverage. Diagonal, 15 percent, orders 113 tiles, 115.00 square feet, and 12 boxes. One hundred times 1.10 is 110.00. One hundred times 1.15 is 115.00. Boxes divide that area by the carton and round up. Type the coverage printed on the box. The 10 square foot start is only there so the division can be checked.
The flooring calculator is rooms, not pieces. Room A at 20 by 15 feet plus room B at 12 by 10 feet is 420.00 square feet. Straight, 10 percent, is 462.00 square feet and 24 boxes at 20 square feet, because 462 ÷ 20 is 23.10 and the count rounds up. Diagonal, 15 percent, is 483.00 square feet and 25 boxes. Herringbone, 20 percent, is 504.00 square feet and 26 boxes. Twenty percent of 420.00 is 84.00. The pattern writes the percent, and you can type over it until you change the pattern again. Piece count for one of those rooms goes back to the tile calculator.
Cuts, large tiles, and what you keep
BuildDirect’s layout step is to find the center, dry-lay tiles from several boxes, and avoid a cut smaller than half a tile at a wall or a door. That is how a careful straight layout stays near the low end of the 10 to 15 percent band. The calculator cannot see the niche, the closet, or the fact that the room is out of square. A bathroom with a toilet and a vanity is more cuts than a rectangle of the same area. Novoceram’s staggered-joint band, about 10 to 12 percent, sits above their straight-joint band for that reason. This site has no staggered preset. Use the editable field.
A large tile wastes differently. One cracked 24 by 48 is several square feet, not a corner offcut. La Tuilerie flags that case and still refuses a single percent. BuildDirect’s 15 inch rule is about the floor being flat within 1/8 inch in 10 feet, and about back-buttering, not about how many extra boxes to buy. If the tile has an edge of 15 inches or more, do not leave the waste field at 10 just because the layout is straight. The 6 by 6 example on the tile page is the other direction: 383.84 tiles and an order of 423, and the boxes stay 11, because boxes follow area.
Attic stock is the leftover after the cuts, kept for a later crack. BuildDirect says to keep a few spare tiles and the box labels, because lot and shade numbers are how you match a repair. La Tuilerie says to buy enough of one batch in the first order, including the loss percent, because a later batch may not match. Novoceram’s 5 percent reserve is written on top of the 7 percent waste in that one example. This site’s waste percent is one number. It is not waste plus a second attic line. If you want a reserve beyond the cuts, raise the percent yourself and label it as your own allowance. Grout is not inside that percent. A 10 by 10 floor of 12 by 12 tile with a 1/8 inch joint and a 3/8 inch depth is 6.51 pounds on the grout calculator. Mortar under the tile is the thinset calculator.
Sources
- BuildDirect, Tile and Stone Installation Guide. Order 10 to 15 percent more, with more for diagonal, herringbone, and other patterns. Keep leftover tile. Large format, for flatness, is any edge 15 inches or longer.
- La Tuilerie, Guide to Successful Renovations. Ten percent for square or rectangular tiles. Fifteen to 20 percent for herringbone or diagonal. Higher losses for large formats such as 24 by 48, especially in a small room. Keep extra tiles from the same batch.
- Novoceram, how to lay floor tiles. Five to 7 percent for a straight joint, about 10 to 12 percent staggered, 15 percent diagonal. The 25 square meter example adds a 5 percent reserve on top of 7 percent waste.
Frequently asked questions
What waste percent does the tile calculator start with?
Straight starts at 10 percent and diagonal at 15 percent. Those are planning allowances. On a 10 by 10 foot floor of 12 by 12 inch tile with a 1/8 inch joint, the tile count stays 97.95. Ten percent orders 108 tiles and 11 boxes at 10 square feet. Fifteen percent orders 113 tiles, 115.00 square feet, and 12 boxes. Type another percent if the carton or the installer names one.
Why is herringbone 20 percent on one page and 15 to 20 in a guide?
La Tuilerie’s renovation guide puts herringbone and diagonal in one band, 15 to 20 percent. The flooring calculator parks diagonal at 15 and herringbone at 20, the two ends of that band, and it labels both as planning allowances. The two-room example is 420.00 square feet. Herringbone reads 504.00 square feet and 26 boxes at 20 square feet. The field stays editable until the pattern changes.
How much extra tile for a large format?
Neither calculator has a large-format preset. La Tuilerie says 24 by 48 and 48 by 48 tiles can need more, especially in a small room, and it does not print a single percent. BuildDirect defines a large format as any edge 15 inches or longer for flatness, and its order line is still 10 to 15 percent, with patterned layouts needing more. Raise the waste field. Do not assume the 10 percent straight start is enough.
Does a smaller tile change the box count?
Not by itself. Boxes follow the floor area after waste, divided by the square feet on the carton. The 10 by 10 floor at 10 percent is 110.00 square feet and 11 boxes at 10 square feet, whether the tile is 12 by 12 or 6 by 6. The 6 by 6 count is 383.84 tiles and an order of 423. The piece count and the box count are different questions.
Is attic stock a second percent?
Not on this site. The waste field is the only allowance, and it is meant to cover cuts and breakage. BuildDirect says to keep leftover tile and a few spares with the lot number. Novoceram’s 25 square meter example writes 7 percent waste plus a separate 5 percent reserve, about 28 square meters. That reserve is their worked example. It is not added again on top of the calculator.
Does the waste percent draw the cuts?
No. The tile line is full modules: area divided by the face plus the joint, in each direction. It does not place tiles or count the slivers at the walls. BuildDirect’s install steps say to dry-lay from the center and avoid cuts smaller than half a tile. That layout work is what the percent is standing in for. Grout in the joints is a separate order, on the grout calculator.