Vison 38 LFT

Product Name: VISON 38 LFT


Manufacturer: Vison Tech Products LLC


Product Description

VISON 38 LFT is a professional formula medium bed mortar with specialized non-sag and non-slump properties for use with large format tile and stone. Fully latex polymer-modified, the VISON 38 LFT is best suited for use as a setting bed thickness of 1/8” to ¾” ( 3-20mm) with tiles and natural stone sizes 15” x 15” and greater. This formula allows for vertical tile and stone attachment to walls with no movement after placement. In use on bonding horizontal substrates, the mortar properties will not shrink or slump after tile placement in floor installations which eliminates uneven tile edges or "lippage". The enhanced mortar also has outstanding adhesion to plywood subfloors. VISON 38 LFT is also ideal for ceramic, porcelain, impervious tiles, and natural stone installations. It’s used for interior or exterior floors, walls, or countertops.



COLOR: Gray or White.

TEXTURE: Powder consisting of Portland cement, polymer additives, graded silica sand, organic and inorganic chemicals.

PACKAGING: 50 lbs. Multi-wall bags.


Basic Use

VISON 38 LFT is used for large format tile setting absorptive, semi-vitreous, vitreous, and non-vitreous (ceramic, mosaic, quarry, cement body tile), impervious tiles, and natural stone.


Key Benefits and Features

Good for bonding ceramic, porcelain, and stone tile; Interior/exterior use. Meets ANSI A118.4 specifications, ANSI 118.11 specifications, and Tile Council North America /TCNA Handbook reference “medium bed mortar”; No additive required – just add water and mix.


Suitable Tile Types

Large format 15” x 15” and greater sized vitreous, semi-vitreous, or non-vitreous tile: ceramic, mosaic, quarry, cement body tile. Impervious porcelain and glass tile; brick and thin brick; cement-based precast terrazzo; natural stone tile.



Not for installing green marble, other moisture-sensitive stone tile, or resin-backed marble. Not for use over rubber, strip wood floors, oriented strand board, particle board, lauan plywood. For CDX plywood, the temperature of the area to be tiled must remain above 50°F (10°C) for 72 hours. Certain natural stone tiles may be affected by mortar shadowing or staining. Heavy tile and natural stone units with weight levels greater than 5 lbs per sq. ft. may require additional spacer/support during the initial 12-24 hour mortar cure.


Applicable Standards

Meets and exceeds requirements for dry-set mortars found in ANSI A118.1, A118.4, A118.11, A108.5, and A108.12


Installation: Mixing

For best results, maintain all tiling materials, substrates, room, and adhesives at 50°-70°F (10-21°C) for 24 hours before and 48 hours after installation. In a clean mixing container, add 50 lbs. (22.68 kg) VISON 38 LFT to 7 quarts (1 3/4 gal) clean, cool water. Mix material to a thick creamy consistency, and then allow the mortar to stand for 10 minutes.


General Surface Prep

All surfaces must be dry, and structurally sound. Remove all grease, oil, dirt, curing compounds, sealers, adhesives, or any other contaminant that would prevent a good bond. Glossy or painted surfaces must be sanded, and stripped of all contaminants. Concrete must be free of efflorescence and not subject to hydrostatic pressure. Concrete slabs should have a coarse finish to enhance the bond. Plywood flooring including those under resilient flooring must be structurally sound and meet all ANSI and deflection requirements. Ambient temperature should be maintained above 50° F (10° C) or below 100° F (38° C) for 72 hours to achieve a proper bond.


Cementitious Substrates

Concrete or plaster must be fully cured and must accept water penetration. Contaminants should be mechanically removed before installation. Concrete must be free of efflorescence and not subject to hydrostatic pressure. Concrete slabs should have a coarse finish to enhance the bond. Smooth concrete slabs must be mechanically abraded to achieve a proper bond.


Non-Cementitious Substrates

All non-conforming surfaces such as strip wood, old plaster, or painted surfaces can be covered with a cleavage membrane topped with a 3/8" - 3/4" (10 – 20 mm) reinforced mortar bed for walls and a 1 1/4" (32 mm) reinforced mortar bed for floors. After a minimum of 20 hours, the dry-set mortar may be applied to the mortar bed.


Tile over Tile and Other Surfaces

The surface must be Portland cement bond compatible, the old surface must be well bonded and without waxes, sealer, or coatings. Smooth or slick surfaces will be heavily scratched, scarred, coarse sanded, or abraded to provide a mechanical bond.


Expansion Joints

Install expansion joints around all perimeters or restraining surfaces where possible to allow for expansion movement. Expansion joints and cold joints, as described in ANSI A108.01, should never be bridged with setting material. They must be brought through the tile work and filled with an appropriate elastomeric sealant. Contact Vison Tech’s Technical Services for the proper treatment of control or saw-cut joints. Refer to TCNA Handbook EJ171



Use a properly-sized notch trowel to ensure proper coverage under tiles. Using the flat side of the trowel, apply a skim coat of mortar to the surface. With the notched side of the trowel held at a 45° angle, apply additional mortar to the surface, combing in one direction. Press the tile firmly into place in a perpendicular motion across ridges, moving back and forth. The perpendicular motion flattens ridges and closes valleys, allowing maximum coverage. Tiles with deep patterns, high lugs, or those with irregular texture on the back surface may require "back buttering" to ensure 100% coverage of back of tiles. The proper method of bonding tiles requires embedding, pressing, and sliding tiles perpendicular to wet mortar ridges to have a nominal mortar thickness of 3/32" - 3/4" (3 - 20 mm) and 100% coverage. During the setting of tile, it is advisable to occasionally remove a tile to be sure mortar has not skinned over and sufficient transfer is being made. Do not adjust tiles in mortar after they have been set past 10 - 15 min. When installing natural stone units, the best practice installation method is to check and remove bond surface dust or lose particles before bonding.


Trowel Recommendation

Smaller tiles will use smaller notched trowels and larger tiles will require larger notched trowels suitable for providing a minimum 3/32" - 3/4" (3 – 20 mm) bed thickness after embedding the tile. Spot bonding or mortar dollops application does not meet installation trade practices and provides proper adhesion and impact support.



Per 50 lbs. (22.7 kg) bag using a square-notched trowel covers:
1/4” x 1/4” = 77 sq. ft. (7.1 m2);
1/4” x 3/8” = 66 sq. ft. (6.1 m2);

1/2“ x 1/2” = 40 sq. ft. (3.7 m2)

1/2“ x 1/2” = 40 sq. ft. (3.7 m2)


Working Time

Approximately 2-3 hours, depending on ambient temperature.



Clean tools, hands, and excess materials from the face of the tile, while the mortar is still fresh, with warm soapy water.


Curing and Grouting

Grouting may be accomplished when tiles are held firmly in place, typically 16 to 24 hours after installation is completed. No traffic is permitted over the tiles prior to grouting. Cold temperatures or high humidity may extend curing time. Unglazed tiles may require sealing prior to grouting so discolorations will not occur.