Merlex Stucco Keeping it Premium since 1963


Matrix Engineered Cement

NAME Matrix Engineered Cement
TYPE Engineered Portland cement for achieving optimal plaster base coats
APPLICATION METHOD Trowel or spray applied
PRODUCT OVERVIEW Merlex Matrix Engineered Cement is a mixture of Portland cement that complies with ASTM C150 and gives improved workability, sag-resistance, and pumpability of the product. Matrix Engineered cement is an acceptable alternative to plastic cement and meets or exceeds ASTM C-926 standards for field-applied Portland cement plaster. Matrix is available either with or without fibers.
BENEFITS Matrix Engineered Cement
  • Better pumping performance than plastic cement and cement-lime mixes
  • Sag-resistant copolymer allows for efficient application and good production rates
  • Proprietary mix design allows for increased sand loads compared to plastic cement mixes
  • Use of optional fibers and/or Basex crack-reduction system over Matrix base coats can drastically reduce surface cracking in new and remodel applications
  • Available with recycled aggregate
SUBSTRATES Merlex Matrix will adhere to any properly applied surface, including lath, masonry, poured-in-place concrete, and any other approved cementitious substrates.
COVERAGE One 90 lb. (40.8 kg) bag covers approximately 80-100 sq. ft. at 3/8” thickness over lath. Typical construction dictates two 3/8” coats.
Coverage will vary with the amount of sand used.
SURFACE PREPARATION For concrete and masonry, all receiving surfaces must be structurally sound, clean, free of all dirt, dust, silicones, efflorescence, organic material, or any other contaminant which could impair the natural bond. Application over masonry and poured concrete may require use of a surface bonder, such as Merlex Superhold. Ensure substrates, water-resistive barrier, and lathing have been installed and inspected. Major cracks, holes, or voids should be repaired prior to application.
MIXING Merlex Matrix should be mechanically mixed for approximately 3 minutes to provide maximum workability. Follow mix specifications in ASTM C-926 standard, and use washed plaster sand that complies with key provisions of ASTM C-897. For the first coat, add 2.5 to 4 parts plaster sand per 1 part Matrix by volume or approximately 225 lb. to 350 lb. (100 kg to 160 kg) per 90 lb. bag of Merlex Matrix Engineered Cement. For the second coat, add 3 to 5 parts plaster sand per 1 part Matrix by volume or approximately 250 lb. to 450 lb. (110 kg to 200 kg) per 90 lb. bag of Matrix Engineered Cement.
Amount of sand added will vary according to moisture content and granulation of plaster sand. The sand:cement ratio should be higher in the second coat than the first. Stop mixer and the material to take its initial set after mixing for 3 minutes. Material may be retempered once adding only enough water to reach the desired consistency.
Do not over mix.
APPLICATION Merlex Matrix should be applied by spraying onto the wall with a pump or alternatively by hand with a trowel. Over lath, apply the mixed Merlex Matrix to a nominal thickness of 3/8” scratch coat and create horizontal lines in the wet material to help support the second base coat. Once the scratch coat has sufficient strength to hold the second coat, apply the mixed Matrix to a nominal thickness of 3/8” brown coat. Bring wet brown coat to an even plane using appropriate tools, taking care not to make too smooth to receive the finish coat. It is recommended to float the brown coat to prepare surface for finish coat. Over masonry or poured concrete, use of a surface bonding agent may be necessary to ensure adhesion and disguise joint lines. Apply the mixed Matrix to a maximum of a ½”. Bring to an even plane and float the brown coat to prepare surface for finish coat.
CLEAN-UP Matrix is designed for enhanced sag-resistance and allows for efficient cleaning of windows and trim with a hose or sponge. Clean promptly after application.
LIMITATIONS Do not apply if ambient temperature will fall below 40°F (4°C) within 24 hours. During periods of hot/dry weather, moist curing may be necessary.
WARRANTY Merlex Matrix Engineered Cement is warranted to perform in accordance with the product specification when used according to application instructions on the label. This warranty is limited to and shall not exceed the total amount paid by the buyer for the product. In no event will Merlex Stucco, Inc. be liable for loss of profits, special or consequential damages in respect to any claim. The foregoing warranties are in lieu of all other warranties express or implied including those concerning fitness for a particular use.
ENVIRONMENTAL & SAFETY Contains Portland cement and is alkaline on contact with water. May be irritating to eyes and skin. Wear appropriate skin and eye protection. In case of eye contact, flush immediately with water. If irritation persists, consult a physician. Wash hands with soap and water after use or before eating food. Keep out of reach of children.
MATERIAL STANDARDS Portland cement: Type 1-ASTM C-150 and ASTM C-926