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Custom VersaBond-LHT (formerly LFT) Coverage Calculator: How Many Bags?
Enter your area and trowel to see how many 50 lb (22.68 kg) bags of VersaBond-LHT large format tile mortar to buy. This is the product CUSTOM used to sell as VersaBond-LFT; the coverage figures come from its current data sheet, TDS-132.
Custom VersaBond-LHT coverage
| Trowel notch | US | Metric |
|---|---|---|
| 1/4" x 1/4" x 1/4" square notch (6 x 6 x 6 mm square notch) | 90–100 sq ft | 8.4–9.3 m² |
| 1/4" x 3/8" x 1/4" square notch (6 x 9.5 x 6 mm square notch) | 60–67 sq ft | 5.6–6.2 m² |
| 1/2" x 1/2" x 1/2" square notch (not recommended by CUSTOM) (13 x 13 x 13 mm square notch) | 42–47 sq ft | 3.9–4.4 m² |
| 3/4" x 9/16" x 3/8" U-notch held at 30° (19 x 14 x 9.5 mm U-notch at 30°) | 42–47 sq ft | 3.9–4.4 m² |
| 3/4" x 9/16" x 3/8" U-notch held at 45° (19 x 14 x 9.5 mm U-notch at 45°) | 34–38 sq ft | 3.2–3.5 m² |
Source: CUSTOM Building Products Technical Data Sheet TDS-132: VersaBond-LHT Professional Large Format Tile Mortar, TDS-132, published August 14, 2026, read 2026-10-16.
How the calculation works
bags = area × (1 + waste ÷ 100) ÷ coverage per bag, rounded up
The manufacturer gives a coverage range for each trowel size because the real figure depends on the tile back, the substrate and how much mortar ends up in the ridges. This calculator divides by the low end of the range, so the number it tells you to buy should not leave you short. If you back-butter large tiles, plan for coverage at or below the low end.
Worked example
A 240 sq ft floor with a 3/4" x 9/16" x 3/8" U-notch held at 30° trowel and 10% extra: 240 × 1.1 = 264 sq ft. At the low end of the coverage range (42 sq ft per bag) that is 264 ÷ 42 = 6.29 bags, so buy 7 (at the high end, 47 sq ft per bag, 6 would be enough). That is 350 lb of powder.
Custom VersaBond-LHT key specs
| Product type | Thinset mortar |
|---|---|
| Bag size | 50 lb (22.68 kg) |
| Mixing water per bag (max) | 6 US qt (5.6 L) |
| Mixing water | 5.5–6 US qt (5.2–5.6 L) per 50 lb bag |
| Slake time | 5–10 minutes, then restir; do not add more water |
| Pot life | 4 hours |
| Open time (ANSI A118.4 section 5.3) | more than 20 minutes |
| Mortar thickness under tile | 3/32" to 3/4" (2.38–19 mm) continuous, after embedding |
| Time before grouting | 24 hours (also light foot traffic) |
| Heavy or vehicular traffic | after 7–10 days |
| Standards | exceeds ANSI A118.4HT and A118.11; complies with ISO 13007-2 |
| Bag sizes and item codes | 50 lb gray (VBLFTMG50) or white (VBLFTMW50) in the US; CVBLFTMG50 / CVBLFTMW50 in Canada |
| Required mortar contact | at least 80% in dry areas, at least 95% in wet areas and exteriors |
VersaBond-LFT is now VersaBond-LHT
If you went looking for VersaBond-LFT, you are in the right place. CUSTOM Building Products now sells this mortar as VersaBond-LHT Professional Large and Heavy Tile Mortar. The product page sits at the same address, the technical data sheet keeps the same number (TDS-132), and the US item codes are unchanged: VBLFTMG50 for gray and VBLFTMW50 for white. The data sheet used on this page was published on August 14, 2026, and it is the version CUSTOM links from the product page today.
The mortar itself is a non-sag, non-slump medium bed mortar for large format porcelain, ceramic and natural stone tile, on floors and walls, inside and out. It exceeds ANSI A118.4HT and A118.11 without any liquid additive, so you mix it with plain water. It is also approved for use over in-floor heating systems.
What it bonds to, and what it does not
TDS-132 lists concrete, mortar beds, masonry and Portland cement plaster; liquid waterproofing membranes such as RedGard; crack isolation sheets such as Crack Buster Pro; uncoupling mats; and surfaces treated with CUSTOM's MBP primer. It also allows exterior-grade plywood in interior residential and light commercial dry areas, gypsum wallboard in interior dry areas, and, once scarified, existing ceramic tile, fully bonded sheet vinyl and plastic laminate. Cutback adhesive is acceptable if the residue is scraped down to a thin, almost transparent film; do not sand or grind it, because old adhesive may contain asbestos.
Keep it off hardwood, luan plywood, particle board, parquet, cushion-backed vinyl, metal, fiberglass, plastic and OSB. For resin-backed stone and moisture-sensitive stone or agglomerate tile, CUSTOM sends you to its epoxy setting products instead, and for clear or translucent glass tile it recommends its Glass Tile mortar.
Choosing a trowel, and why the default is a U-notch
The coverage chart gives five rows. The two small square notches suit standard tile: 90 to 100 sq ft per bag at 1/4 x 1/4 inch and 60 to 67 sq ft at 1/4 x 3/8 inch. For large format tile you need more mortar, and here the data sheet is unusually direct. It lists 42 to 47 sq ft for a 1/2 inch square notch but says CUSTOM does not recommend that trowel, because the wide gaps between notches make tile harder to bed and full contact harder to reach.
What CUSTOM suggests instead is a 3/4 x 9/16 x 3/8 inch U-notch trowel held at about 30 degrees. Its ridges collapse more readily under the tile and it uses the same amount of mortar as the 1/2 inch notch, 42 to 47 sq ft per bag. Hold the same trowel more upright, at 45 degrees, and it lays down more mortar, so coverage drops to 34 to 38 sq ft. That is why the calculator starts on the U-notch at 30 degrees; switch to the 45 degree row if that is how you trowel.
As with every product on this site, the calculator uses the low end of the range and rounds up to whole bags. For 100 sq ft plus 10% waste with the default trowel, that is 110 ÷ 42 = 2.6, so 3 bags.
Coverage is about contact, not just bags
The chart is an estimate. CUSTOM requires at least 80% mortar contact under the tile in dry areas and at least 95% in wet areas and outdoors, with every edge supported. After embedding, the bed must be continuous and between 3/32 inch and 3/4 inch thick. Large tile, tile with deep back patterns and ungauged stone may need a bigger notch plus back troweling, and the mortar you spread on the back of each tile is not included in the chart. If you back-butter, add an allowance based on the depth of the tile's back pattern, or raise the waste setting. Lift a tile now and then to check contact; CUSTOM's own warranty guidance recommends testing it.
Mixing, timing and curing
Use 5.5 to 6 US quarts (5.2 to 5.6 L) of clean water per 50 lb bag. Mix by hand or with a 1/2 inch drill at a low 150 to 200 RPM until smooth, let it slake for 5 to 10 minutes, then stir again. Pot life is about 4 hours. Stir now and then as you work, but do not add water to loosen it; properly mixed, the trowel ridges should stand without slumping.
Open time is more than 20 minutes under the ANSI test, so spread only what you can cover while the surface is still tacky. CUSTOM's guideline is 24 hours before grouting and light foot traffic and 7 to 10 days before heavy or vehicular traffic. Low temperatures and high humidity stretch those times.
Common mistakes
- Buying for a 1/2 inch square notch when you plan to back-butter large tile, then running short. Add the back-butter mortar to your estimate.
- Adding water when the mix starts to stiffen. Restir instead; extra water weakens the bond and lets the ridges slump.
- Setting over OSB or a bouncy floor. Plywood floors must meet L/360 deflection for tile and L/720 for stone.
- Bridging movement joints with mortar. Perimeter and change-of-plane joints must carry through the tile and be filled with a flexible sealant.
Comparing options? The thinset coverage table puts this mortar next to MAPEI's Ultraflex 2 LT, which also lists a 3/4 inch U-notch.
FAQ
Is VersaBond-LHT the same product as VersaBond-LFT?
CUSTOM now sells it as VersaBond-LHT Professional Large and Heavy Tile Mortar, but it keeps the same data sheet number (TDS-132), the same web address and the same item codes (VBLFTMG50 gray, VBLFTMW50 white). If you have a bag labeled VersaBond-LFT, the coverage chart on this page is the one to use.
How much does a 50 lb bag of VersaBond-LHT cover?
CUSTOM's chart gives 90 to 100 sq ft with a 1/4 x 1/4 inch square notch, 60 to 67 sq ft with 1/4 x 3/8 inch, 42 to 47 sq ft with a 3/4 inch U-notch held at 30 degrees, and 34 to 38 sq ft with the same U-notch held at 45 degrees. The calculator uses the low end of each range.
Why does CUSTOM not recommend a 1/2 inch square notch trowel?
The data sheet says the 1/2 inch gaps between square notches make it harder to bed the tile and get full mortar contact. It recommends a trowel whose ridges collapse more easily, such as a 3/4 x 9/16 x 3/8 inch U-notch at a 30 degree angle, which uses the same amount of mortar as a 1/2 inch notch.
How much water do I mix into a bag?
5.5 to 6 US quarts (5.2 to 5.6 L) of clean water per 50 lb bag. Mix by hand or with a drill at 150 to 200 RPM, let it slake 5 to 10 minutes, then stir again. Stir occasionally while you work but do not add more water.
How long before I can grout?
CUSTOM gives 24 hours before grouting and light foot traffic, and 7 to 10 days before heavy or vehicular traffic, as a guide. Cold, damp conditions slow curing, so allow longer if the job site is cool.
CUSTOM Building Products and Custom VersaBond-LHT are trademarks of their owner. This page is an independent estimate based on the published data sheet; check the bag label before mixing.