MegaLite® RS Ultimate Rapid Setting Crack Prevention Large Format Tile Mortar

Product ID: TDS-120

A premium one part formula with the high, fast bond strengths and flexibility to withstand horizontal movement to isolate substrate cracks. For time-critical commercial and residential installations under the most demanding requirements, capable of thin-set or medium bed application up to 3/4″ (19 mm) thick on horizontal surfaces after beat in. Non-slump, medium-bed features provide the ultimate support for large format tile and stone. No need for two part additives to meet high bond and flexibility or compressive strength requirements. The rapid setting formula allows grouting in less than 3 hours, traffic in 4 hours. A 30 lb (13.6 kg) bag covers the same area as a 50 lb (22.68 kg) bag of traditional mortar. Use for interior or exterior floors, countertops and walls. Formulated with recycled material contributes to LEED® certification. Exceeds ANSI A118.4, A118.15 and A118.11 without the need for additives.

  • Fast curing – Grout in 3 hours, open for traffic in 4 hours
  • Unsurpassed bond strength and flexibility
  • Non-slump for floors, sag and slip resistant for walls
  • Lightweight – 30 lbs. covers the same area as 50 lbs. of traditional mortar

Coverage Chart


Trowel Size Min Coverage Max Coverage
Longest side of tile less than 8" use 1/4" x 1/4" x 1/4" (6 x 6 x 6 mm) Square-Notch 90 sq. ft. (8.4 M²) 100 sq. ft. (9.3 M²)
Longest side of tile 8" to 15" use 1/4" x 3/8" x 1/4" (6 x 9.5 x 6 mm) Square-Notch 63 sq. ft. (5.8 M²) 70 sq. ft. (6.5 M²)
Longest side of tile more than 15"+ use 1/2" x 1/2" x 1/2" (13 x 13 x 13 mm) Square-Notch 45 sq. ft. (4.2 M²) 50 sq. ft. (4.6 M²)
Longest side of tile more than 15"+ use 3/4" × 9/16" × 3/8" (19 × 14 × 9.5 mm) U-Notch 36 sq. ft. (3.3 M²) 40 sq. ft. (3.7 M²)

Recommended minimum coverage (80% for dry areas and 95% for wet areas and exteriors). Back buttering may be necessary.

Note that mortar coverage does not include backbuttering tiles. When backbuttering, consider the tile underside pattern and depth to estimate thickness and usage to add to your estimate.

Chart for estimating purposes. Coverage may vary based on installation practices and jobsite conditions. For more sizes, use the material calculator at or contact CUSTOM Technical Services at 800-282-8786.

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