Products : JAMO : Setting Materials : Multi Floor-Set Mortar

Multi Floor-Set Mortar

MULTI FLOOR-SET MORTAR offers economy and good bond strength for floor tile installations. Apply over concrete subfloors, cement backerboards and existing ceramic tile. Meets ANSI A118.4.

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Bonds vitreous, semi-vitreous or absorptive tile including ceramic, mosaic, quarry, cement, porcelain; brick and mini-brick; precast terrazzo and natural stone.


TDS Documents

Technical Data Sheet


Suitable Substrates

Interior or exterior floors or countertops; concrete, mortar beds, masonry, Portland cement plaster; cement backerboards, WonderBoard® Backerboard; gypsum wall board (dry areas) and existing ceramic tile.

General Surface Prep

General Surface Preparation Surfaces must be structurally sound, clean, dry and free from grease, oil, dirt, curing compounds, sealers, adhesives or any other contaminant that would prevent a good bond. Glossy or painted surfaces must be sanded, stripped and cleaned of waxes, dirt or any contaminants. Ambient temperature, surfaces and materials should be maintained at a temperature above 50° F (10° C) or below 100° F (38° C) for 72 hours

Movement Joint Placement

Expansion joints, control joints and cold joints should never be bridged with setting material. They must be brought through the tile work and filled with an appropriate elastomeric sealant.

Health Precautions

Contains Portland cement. Wear rubber gloves and eye protection. Avoid eye contact or prolonged contact with skin. Wash thoroughly after handling. If eye contact occurs, flush with water for 15 minutes. Consult a physician immediately. WARNING! Do Not Breathe Dust! This product contains Free Silica which may cause cancer or delayed lung injury (Silicosis). Wear approved respirator in dusty areas. See Material Safety Data Sheet for detailed information. KEEP OUT OF REACH OF CHILDREN. DO NOT TAKE INTERNALLY. STORE IN COOL, DRY AREA.

Limitations to the Product

Do not bond directly to hardwood, Luan plywood, particle board, parquet, cushion or sponge-back vinyl flooring, metal, fiberglass, plastic and OSB panels. When setting moisture sensitive stone, tile or agglomerates (check with manufacturer) use EBM-Lite™ Epoxy Bonding Mortar—100% Solids. Do not use to install resin-backed stone. When setting dimensional stone larger than 12" x 12" (30 x 30 cm), contact Technical Services for recommendations regarding subfloor deflection requirements.

Bonding to Concrete Surfaces

Concrete or plaster must be fully cured and accept water penetration. Test by sprinkling water on various areas of the substrate. If water penetrates, then a good bond can be achieved. If water beads, surface contaminants are present and loss of adhesion may occur. The contaminants should be removed before installation. Concrete must be free of efflorescence and not subject to hydrostatic pressure. Concrete slabs should have a broomed or brushed finish to enhance the bond. Smooth concrete slabs must be roughened to ensure a good bond.

Bonding to Backerboards

As a superior alternative to an additional layer of plywood, WonderBoard Backerboards may be installed over plywood subfloors. Refer to the data sheets for installation information.

Bonding to Existing Surfacing Material

For existing well-bonded ceramic tile, mechanically abrade with carborundum stone. Rinse and allow to dry. When sanding we recommend the use of an approved respirator.

Mixing Procedures

Thoroughly mix 6 quarts (5.68 L) clean, cool water and a 50 lb. (22.68 kg) bag of powder together to a smooth, paste-like consistency. When setting over exterior grade plywood, use 6 quarts of STAR SET® 1000 in place of water. Mix by hand or use a low speed (150 – 200 RPM) 1/2" (13 mm) drill. Let slake or stand 5 – 10 minutes, stir again and use. Stir occasionally to keep fluffy, but do not add more water. When properly mixed, troweled ridges will stand with no slump.

Application of Product

INSTALLATION TO CONFORM TO ANSI A108.5. Use proper sized notched trowel to ensure 100% coverage under tiles. Using flat side of trowel, apply skim coat of mortar to the surface. Apply additional mortar with notched side of trowel held at a 45° angle to the surface, combing in one direction. Press tile firmly into place in a perpendicular motion across ridges, moving back and forth. Perpendicular pressing flattens ridges and closes valleys allowing maximum coverage. With some tile, back buttering is advisable. Adjust tile promptly and beat in with block and rubber mallet. Periodically pull up a tile and check the back to ensure complete coverage with the adhesive. Do not spread more material than can be tiled in 15 minutes or while material has wet tack (sticky to the touch). If material has skinned over (not sticky), recomb with notched trowel. If too dry, remove and replace with fresh material. Material in bucket will remain workable approximately 2 hours.

Curing of Product

Allow to cure for a minimum of 24 hours before grouting or light traffic, depending upon temperature and humidity. MASTER COLOR™ Grout is recommended.

Cleaning of equipment

Clean with water before material dries


Store in a cool dry area.

Warranty Information

Product Warranty

Manufacturer warrants that should this product prove to be defective material, it will replace the same or refund the purchase price of the goods. THIS WARRANTY IS IN PLACE OF ALL OTHER WARRANTS EXPRESS OR IMPLIED. WARRANTIES OF MERCHANTABILITY AND OF FITNESS ARE HEREBY DISCLAIMED. The suitability of a product for an intended use shall be solely up to the user. Manufacturer assumes no liability for consequential damages. Its liability shall in no event exceed the purchase price of the materials supplied by it. No person has the authority to change these items and there are no warranties except herein stated.

Coverage Chart

80 - 90 sq. ft. per 50 lbs. (7.4 - 8.4 M2 /22.68 kg) applied with a 1/4" x 1/4" x 1/4" (6 x 6 x 6 mm) square-notch trowel.

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