Products : JAMO : Setting Materials : Jamo-Set Polymer-Modified Thin-Set Mortar

Jamo-Set Polymer-Modified Thin-Set Mortar

JAMO-SET is a high performance modified thin-set mortar that delivers good bond strengths for basic tile and natural stone installations over most common types of surfaces. Meets ANSI A118.4 and A118.11 mixed with water. No need for additives.

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


TDS Documents

Technical Data Sheet


Suitable Substrates

Interior or exterior floors, countertops, walls. Concrete, mortar beds, masonry, Portland cement plaster. WonderBoard® , EasyBoard® backerboards. Exterior grade plywood (interior residential and light commercial dry areas). Gypsum wall board (dry areas). 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 STAR EPOXY MORTAR. 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

Cementitious 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 Plywood Surfaces

Plywood floors including those under resilient flooring must be built to industry standards. Deflection not to exceed L/360. For questions about proper subfloor installation, call Technical Services.


Bonding to Backerboards

Backerboards and Underlayments

Tile backerboards such as WonderBoard® and EasyBoard® are a superior alternative to using a second layer of plywood as a final substrate for tile installation. EasyMat ® is an underlayment that can be used in the same regard. Each provide unique benefits to tile installation but all can be installed over plywood to ensure that maximum bond strengths and performance are achieved. Refer to respective data sheet for installation information.

Bonding to Existing Surfacing Material

Existing Ceramic Tile, Resilient Flooring or Plastic Laminates

Plywood flooring must be structurally sound and meet all ANSI and deflection requirements. Resilient flooring or plastic laminates must be well bonded, clean and free of all contaminates. Roughen the surface by sanding or scarifying, rinse and allow to dry. Do not sand flooring containing asbestos. 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.

Bonding to Cutback Adhesive

Adhesive layers must be removed as they reduce mortar bond strength to cement surfaces. Use extreme caution as adhesives may contain asbestos fibers. Do not sand or grind adhesive residue, as harmful dust may result. Never use adhesive removers or solvents, as they soften the adhesive and may cause it to penetrate into the concrete. Adhesive residue must be wet-scraped to the finished surface of the concrete, leaving only the transparent staining from the glue. Do a test bond area first, to determine desirable results. Refer to the RFCI Pamphlet, “Recommended Work Practices for Removal of Resilient Floor Coverings” for further information.

Mixing Procedures

Thoroughly mix 6 quarts (5.68 L) clean, cool water and a 50 lb. (22.68 kg) bag of JAMO- -SET together to a smooth, paste-like consistency. 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

Application INSTALLATION TO CONFORM TO ANSI A108.5. Use proper sized notch 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. Mortar can be applied up to 1/4" (6 mm) thick after beat in. For thicker applications, use a medium bed mortar. 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 in excess of 4 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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