Dryvit Primus DM 50lb: Adhesive/Base Coat

Dryvit Primus DM 50lb: Adhesive/Base Coat

Dryvit Primus DM is a dry mix, polymer-modified, cementitious adhesive and base coat. It is supplied in 50 lb (22.7 kg) bags and, when mixed with water at the job site, produces a high performance, easily applied adhesive and base coat for use with Dryvit systems. Questions? Contact Us.

Dryvit Primus DM is used to adhere expanded polystyrene insulation board to acceptable substrates and to embed reinforcing mesh as part of the base coat for Dryvit systems.

Working Time: After mixing, the working time of the Primus DM mixture is approximately 1-3 hours depending on ambient weather conditions.

Drying Time: Drying time of the Primus DM mixture is dependent on the air temperature and relative humidity. Under average drying conditions [70 °F (21 °C), 55% R.H.], the Primus DM mixture will dry in 24 hours. Protect work from rain for at least 24 hours. Being a cementitious product, the Primus DM mixture develops full strength in 28 days. When used to bond expanded polystyrene insulation board to an acceptable substrate, a period of 24 hours must elapse to allow the Primus DM mixture to form a positive bond. The installed insulation board should not be disturbed until adequate bond has developed.

Testing Information: For individual test data on this product’s properties, refer to the chart included with this document.

Application Procedure: For complete application instructions, refer to the appropriate Dryvit system application instructions.

Job Conditions: Air and surface temperatures for application of the Primus DM mixture must be 40 °F (4 °C) or higher and must remain so for a minimum of 24 hours.

Temporary Protection: Shall be provided at all times until the adhesive, base coat, finish and installation of permanent flashings, sealants, etc. are completed to protect the wall from inclement weather and other sources of damage.

Acceptable Substrates:
• Exterior grade gypsum sheathing meeting ASTM C 1396 (formerly C 79) requirements for water-resistant core or Type X core
• Exterior sheathing having a water-resistant core with fiberglass mat facers meeting ASTM C 1177
• Exterior fiber reinforced cement or calcium silicate boards
• Unglazed brick, cement plaster, concrete or masonry
• Galvanized expanded metal lath 2.5 or 3.4 lbs/yd² (1.4 or 1.8 kg/m²) installed over a solid substrate