Home › Tile grout › Custom CEG-Lite
CEG-Lite Epoxy Grout Calculator: How Many Units Do You Need?
Enter your area, tile size and joint width to see how much CEG-Lite epoxy grout to buy and which mix of 1 gallon units (one Part A 1.3 lb color tub + one 9.5 lb Part B pail) and 2 gallon units (two Part A tubs + one 19 lb Part B pail) covers it. The calculator uses a joint-volume formula calibrated against the coverage chart in Custom Building Products TDS-101 (published 3/22/2023) and never claims more coverage than the chart. For 12 x 12 in tile with 1/8 in joints, Custom's chart gives 187 sq ft per 1 gallon unit; the calculator gives about 186.
Custom CEG-Lite coverage
| Tile | 1/16 in | 1/8 in | 3/16 in | 1/4 in | 3/8 in | 1/2 in |
|---|---|---|---|---|---|---|
| 1 x 1 x 1/4 in | 52 | 29 | 21 | 18 | 14 | 13 |
| 2 x 2 x 1/4 in | 97 | 52 | 36 | 29 | 21 | 18 |
| 3 x 3 x 1/4 in | 143 | 74 | 52 | 40 | 29 | 23 |
| 4 1/4 x 4 1/4 x 1/4 in | 200 | 103 | 71 | 54 | 38 | 30 |
| 4 x 8 x 1/2 in | 125 | 64 | 44 | 33 | 23 | 18 |
| 6 x 6 x 1/4 in | 280 | 143 | 97 | 74 | 52 | 40 |
| 6 x 6 x 1/2 in | 140 | 71 | 49 | 37 | 26 | 20 |
| 8 x 8 x 3/8 in | 248 | 126 | 85 | 65 | 45 | 34 |
| 12 x 12 x 3/8 in | 369 | 187 | 126 | 95 | 65 | 50 |
| 16 x 16 x 3/8 in | 491 | 248 | 166 | 126 | 85 | 65 |
| 18 x 18 x 3/8 in | 552 | 278 | 187 | 141 | 95 | 72 |
| 20 x 20 x 3/8 in | 613 | 309 | 207 | 156 | 105 | 80 |
| 24 x 24 x 3/8 in | 735 | 369 | 248 | 187 | 126 | 95 |
| 6 x 24 x 3/8 in | 296 | 150 | 101 | 77 | 53 | 40 |
| 12 x 24 x 3/8 in | 491 | 248 | 166 | 126 | 85 | 65 |
| 6 x 36 x 3/8 in | 317 | 161 | 108 | 82 | 56 | 43 |
| 9 x 36 x 3/8 in | 443 | 223 | 150 | 114 | 77 | 59 |
| 12 x 48 x 3/8 in | 589 | 296 | 199 | 150 | 101 | 77 |
Source: Custom Building Products Technical Data Sheet TDS-101: CEG-Lite 100% Solids Commercial Epoxy Grout, Published 3/22/2023, read 2026-10-18.
How the calculation works
grout per sq ft = 144 × ((L + W) × J + J²) × T ÷ ((L + J) × (W + J))
units = area × (1 + waste ÷ 100) × grout per sq ft ÷ joint volume one unit fills, rounded up
L and W are the tile length and width, T the tile thickness (the joint is assumed to be filled to full tile depth) and J the joint width, all in inches; the result is in cubic inches. The volume one unit fills is worked back from the manufacturer's coverage chart and set at the lowest value any cell of the chart implies, so for every tile size in the chart this calculator gives the same or less coverage than the data sheet, never more. Tiles not in the chart use the same formula.
Worked example
A 200 sq ft floor of 12 x 12 x 3/8 in tile with 1/8 in joints and 10% extra: 220 sq ft to grout. Each tile plus its share of joint is a 12.125 × 12.125 in square, and the joint part of it holds (12 + 12) × 1/8 + 1/8² = 3.016 sq in, 3/8 in deep. That works out to 1.11 cubic inches of grout per sq ft of floor. One 1 gal unit (Part A 1.3 lb + Part B 9.5 lb) fills about 206 cubic inches of joint, so it covers 206 ÷ 1.11 = 185.8 sq ft. 220 ÷ 185.8 = 1.18 units of 1 gal unit (Part A 1.3 lb + Part B 9.5 lb), or 1.18 × 1 gal = 1.18 gallons of mixed grout. In the sizes on sale, buy 1 × 2 gal unit (2 gal).
Custom CEG-Lite key specs
| Product type | Tile grout |
|---|---|
| Package | 1 gal unit (Part A 1.3 lb + Part B 9.5 lb) |
| Joint width range | 1/16–1/2 in |
| Coverage (data sheet, per 1 gal unit) | 12 x 12 x 3/8" tile 369 sq ft at 1/16", 187 at 1/8", 95 at 1/4", 50 at 1/2"; 1 x 1 x 1/4" mosaic 52 sq ft at 1/16", 29 at 1/8"; the 19 lb Part B size covers double (full chart above) |
| What you buy | two separately sold parts: Part A 1.3 lb (0.58 kg) pigmented liquid hardener tub, 40 standard colors; Part B liquid epoxy resin with aggregate, 9.5 lb (4.3 kg) or 19 lb (8.6 kg) pail. 1 gal unit = 1 Part A + 9.5 lb Part B; 2 gal unit = 2 Part A + 19 lb Part B |
| Item codes | Part B LWCEGB1-EA (9.5 lb), LWCEGB2 (19 lb); Part A LWCEG + color number + A-EA |
| Joint width | 1/16" to 1/2" (1.6–13 mm); contains silica aggregate, so test on glass, metal, polished stone or other scratch-prone tile |
| Mixing | stir Part B, add the entire Part A, mix with a power mixer at 300 RPM or less; do not mix partial units or overmix |
| Working time | pot life about 60 minutes at 75°F (24°C); finish all grouting and cleaning within 80 minutes; easiest to apply at 70–85°F (21–29°C) |
| Cure | light traffic after 7 hours at 70°F, 50% RH; protect from harsh industrial cleaners 7 days and aggressive chemicals 14 days; clean water only for the first 7 days |
| Pools and continually wet areas | cure the complete installation 14 days before full submersion in chemically treated water |
| Exterior | protect from rain and snow at least 7 days above 50°F (10°C); keep above 50°F for at least 72 hours |
| Surface temperature | 65–95°F (18–35°C) |
| Strength | compressive 5,800 psi, tensile 1,700 psi, shrinkage 0.08% (ANSI A118.3 tests); exceeds ANSI A118.3 |
| Sealing | not required |
| Also a mortar | per 1 gal unit: 1/4 x 1/4 x 1/4" square notch 26.6–29.2 sq ft; 1/4 x 3/8 x 1/4" U-notch 18.6–21.3 sq ft (double for the 19 lb size) |
| Not for | movement joints and changes of plane (use caulk), sustained temperatures above 250°F (121°C), commercial kitchens with harsh cleaners and industrial plants (Custom points to CEG-IG), non-rinse enzyme cleaners |
What CEG-Lite is
CEG-Lite 100% Solids Commercial Epoxy Grout from Custom Building Products is a two-part epoxy grout for floors and walls, inside and out. Part A is a pigmented liquid hardener that also carries the color; Part B is a liquid epoxy resin already blended with lightweight aggregate. Custom's pitch is that the lightweight formula spreads more easily than typical epoxy grouts and cleans up with water, while still giving the stain and chemical resistance epoxy is chosen for. It exceeds ANSI A118.3, does not need sealing, does not sag in vertical joints without an additive, and can also be used as a setting mortar.
Data sheet TDS-101 lists countertops, backsplashes, tub and shower areas, sunken tubs and swimming pools that stay wet, plus areas that need chemical resistance. It works with ceramic, mosaic, quarry, pavers, porcelain, glass, brick, precast terrazzo and natural stone, including green marble. For commercial kitchens with harsh cleaners and for industrial plants, Custom points you to its heavier CEG-IG Industrial Grade Epoxy Grout instead.
How a CEG-Lite unit is put together
This is the part that trips people up at the store. CEG-Lite is not sold as one box. You buy a Part A color tub (1.3 lb, 0.58 kg, in 40 standard colors) and a Part B pail separately, and Part B comes in two sizes:
- 1 gallon unit: one 1.3 lb Part A tub plus one 9.5 lb (4.3 kg) Part B pail (item LWCEGB1-EA).
- 2 gallon unit: two 1.3 lb Part A tubs plus one 19 lb (8.6 kg) Part B pail (item LWCEGB2).
The data sheet stresses this in capital letters: the larger Part B needs two Part A tubs, and the grout will not harden or reach its color if the ratio is wrong. So when the calculator says "2 units of 2 gal", your shopping list is two 19 lb Part B pails and four Part A tubs in your color.
How the calculator works
Grout fills only the gaps between tiles, so the amount depends on how much joint there is per square foot of floor. The calculator treats each tile plus half the joint on each side as a rectangle (L + J) by (W + J), where L and W are the tile length and width and J the joint width. The joint share of that rectangle is (L + W) × J + J² square inches. Multiplying by the tile thickness T, because the joint is filled full depth, and dividing by the rectangle's area gives grout per square inch of floor; times 144 gives cubic inches per square foot.
Custom does not print how much joint volume one unit fills, so that number was worked back from all 108 cells of the TDS-101 chart (18 tile sizes by 6 joint widths). On this chart the result is unusually even: every cell for tile 4 inches and larger lands between about 206 and 215 cubic inches per 1 gallon unit, and only small mosaics with wide joints go higher. The calculator uses 205.8 cubic inches, the lowest value any cell implies, so for every tile and joint in the chart it gives the same or slightly less coverage than Custom does, never more. For 12 x 12 x 3/8 inch tile with 1/8 inch joints it gives about 186 sq ft per unit against Custom's 187.
Once it knows how many gallons the job needs, it picks a mix of 1 and 2 gallon units: the fewest units that cover the job without leaving more than one 1 gallon unit's worth unused. You can then swap a 2 gallon unit for two 1 gallon units if that suits the working time better.
Entering your tile and joint
Use the tile's actual size, not its nominal name, if they differ much, and use the real thickness, because the joint is assumed to be filled to the full tile depth. If you will set tile in a thin layer and grout only part of the depth, the calculator will overestimate slightly, which is the safe direction. The joint options run from 1/16 to 1/2 inch, the range TDS-101 allows. Add a waste allowance; 10 percent is common for epoxy, and more for rough or textured tile where some grout ends up on the surface and is washed away.
Mixing and working time
Stir Part B first to bring back any settled aggregate, then add the whole Part A and mix with a power mixer at 300 RPM or less, scraping the sides and bottom. Mixing too fast traps air and leaves pinholes; overmixing can make the epoxy flash set. Do not split units, because the parts are portioned to cure together. Pot life is about 60 minutes at 75°F (24°C), and Custom asks for all grouting and cleaning to be finished within 80 minutes. Spreading the mixed grout out in piles over the floor right away extends working time.
Epoxy is temperature sensitive. TDS-101 calls 70 to 85°F (21 to 29°C) the easiest range; colder grout gets stiff and slow, warmer grout runs and sets faster. Surfaces must be between 65 and 95°F (18 and 35°C). If the resin has crystallized from cold storage, the data sheet says to warm the sealed pail in about 120°F water for 10 to 20 minutes and let it come back to room temperature before mixing.
Cure and use
At 70°F and 50 percent humidity, the floor takes light foot traffic after 7 hours; narrow joints and cool sites take longer. Keep harsh industrial cleaners off for 7 days and aggressive chemicals for 14 days, and clean with plain water for the first week. For pools, gang showers and other continually wet installations, let the whole installation cure 14 days before filling with chemically treated water. Exterior work needs protection from rain and snow for at least 7 days above 50°F (10°C).
Check before you buy
The silica aggregate can scratch some glass, metal, polished marble or stone tiles, so Custom recommends a small test first. Porous or rough tile may need a grout release beforehand to avoid staining. Do not use CEG-Lite in movement joints or at changes of plane; use a sealant there. Avoid non-rinse enzyme cleaners, which TDS-101 says break down epoxy grout. The coverage chart is for estimating, and Custom notes that real use depends on installation practice and jobsite conditions; for odd tile sizes it offers a material calculator and technical services at 800-282-8786.
FAQ
How much does a unit of CEG-Lite cover?
It depends on tile size and joint width. Custom's TDS-101 chart is printed per 1 gallon unit (one 1.3 lb Part A plus one 9.5 lb Part B): 187 sq ft for 12 x 12 x 3/8 inch tile with 1/8 inch joints, 369 sq ft at 1/16 inch and 95 sq ft at 1/4 inch. Small mosaics take much more: 1 x 1 inch mosaic at 1/8 inch joints covers only 29 sq ft. The 19 lb Part B size covers double the chart values.
What exactly do I need to buy for one unit?
CEG-Lite is sold as two separate items. Part A is a 1.3 lb tub of pigmented hardener, and its color is the grout color. Part B is the resin and aggregate in a 9.5 lb or 19 lb pail. A 1 gallon unit is one Part A tub with one 9.5 lb Part B; a 2 gallon unit is two Part A tubs with one 19 lb Part B. Buy both parts for every unit the calculator shows, because the grout will not harden or reach its color if mixed wrong.
Why does the calculator show slightly less coverage than the chart?
It uses one joint-volume formula for every tile and joint, with the volume per unit set at the lowest value any cell of Custom's chart implies, about 205.8 cubic inches. Worked back, almost every cell falls between 206 and 212 cubic inches, so the calculator is within about 1 to 2 percent of the chart for normal tile. Small mosaics with wide joints are where the chart is more generous, so the calculator stays on the safe side there.
Can I mix half a unit to save grout?
No. TDS-101 says not to mix partial units, because the hardener and resin are portioned to cure together. That is why the calculator rounds up to whole units. It picks the fewest units that cover the job without leaving more than one 1 gallon unit unused, so a job needing 1.2 gallons gets one 2 gallon unit. With a 60 minute pot life, though, two 1 gallon units mixed one at a time can be easier to finish than one big batch, and they cover the same area.
Is CEG-Lite right for a commercial kitchen or pool?
For pools, showers and other continually wet areas, yes: the data sheet lists swimming pools and asks for a 14 day cure before full submersion in chemically treated water. For commercial kitchens that use harsh chemical cleaners and for industrial settings, Custom recommends its CEG-IG Industrial Grade Epoxy Grout instead, and the chemical resistance chart in TDS-101 should be checked for anything unusual.
Custom Building Products and Custom CEG-Lite are trademarks of their owner. This page is an independent estimate based on the published data sheet; check the bag label before mixing.