MATERIALS
Thin bed mortar materials shall be composed of Portland Cement and sand gauged with Mer-Krete Latex 200 as manufactured by Mer- Kote Products, Inc. Grout materials shall be composed of Portland Cement and sand or prepared colored grouts gauged with Mer-Krete 150 Acrylic Latex as manufactured by Mer-Krete Products, Inc.
The supplier of mortar additives shall have been regularly engaged in the manufacture of these materials for a minimum of five years. Mortar bed and grout materials shall be made weather, water and frost resistant using Latex 200 and shall meet the following physical requirements:
1. Compressive Strength – minimum of 4,000 p.s.i.
2. Adhesive Bond Strength (In Shear) – minimum of 330 p.s.i. in 48 hours.
3. Water Absorption – Less than 4%
4. Linear Shrinkage – None
The finished mortar and grout shall be resistant to urine, diluted acid and alkali, sugar, brine and other food waste products.

SUBSURFACE PREPARATION
Areas requiring fill, patching or leveling shall be prepared by the General Contractor using 150 Latex with Underlay-M Filler in accordance with manufacturer’s instructions. Gypsum based leveling compounds shall not be used. The concrete surface to be covered shall be left clean and free of dust, plaster, sealer, curing compounds and any form of oil. Any such contamination shall be removed by the General Contractor. Dry or dusty concrete surfaces should be wet down or washed and excess water removed just prior to installation of the covering.

*NOTE: CSI format specifications are available on floppy disc from any Mer-Krete office.

INSTALLATION (THIN SET METHOD)
1. Setting mortar shall be mixed at the rate of one sack (94 lbs.) of gray or white Portland Cement, one sack (100 lbs.) of clean fine sand (30-50 mesh) and five gallons of Latex 200 or 11/4 gallons Latex 200 with one 50 lb. sack Filler 211. Adjust mixture by adding more or less powder.
2. Apply mortar with a notched trowel (1/4" x 1/4" or 3/8" x 1/4") using a scraping motion to ensure good contact with the surface to be covered.
3. Apply only as much mortar as can be covered in 20-30 minutes or before skinning occurs. Mortar shall be applied to the back of the tile, stone, etc. prior to setting. Tile, stone, etc. shall be rapped or beaten with a beating block after setting to level and to ensure proper bonding. Ensure proper alignment to show uniform joints and allow to set until firm.
4. Excess mortar shall be cleaned from the exposed surface with a wet cloth or sponge while the mortar is fresh.

EXPANSION JOINTS
Expansion joints shall be installed against all restraining surfaces (walls, curbs, columns, wall corners, etc.) and directly over joints in structural surfaces. Expansion joints shall conform to the recommendations in the current Tile Council of America Handbook.
Large surface areas shall also have expansion joints spaced in conformance with the latest Tile Council of America Handbook.
Expansion joints shall be filled with a sealant in a color to match the tile, stone, etc. Sealant joint, when filled, shall be liberally sprinkled with a dry mortar mix to closely match mortar joints.

GROUTING
After the installation is firm, grouting may commence as follows:
1. Grout mortar shall be mixed at the rate of one part Portland Cement, one or two parts clean fine sand (40-60 mesh) depending on joint width and a quantity of 150 Acrylic Latex sufficient to provide a workable mix.
2. Metal Oxide, to provide color if desired, shall be added to the dry mix prior to wetting with Mer-Krete Additive. For prepared or commercially colored grouts, add approximately one gallon of 150 Acrylic Latex to 50 lb. of pre-blended grout powder.
3. Grouting shall be accomplished by carefully filling all open joints and voids. A mortar bag may be used to grout non-precision joints. Tool or rake the joints as specified.
4. Excess grout shall be removed promptly from the surface prior to initial setting. If difficulty is encountered cleaning or removing grout, use a tile cleaner with a nylon scrubbing pad.

PROTECTION
The Tile Contractor shall take precautions to protect the finished work from damage by other trades.

*Note: The setting of Portland Cement mortars is retarded by low temperatures and the finished work must be protected for an extended period of time. Manufacturer DOES NOT recommend installations below 45°F or when freezing temperatures may occur before the mortar has set.