CM 900 Industrial Base

The substrate should be clean and free of dust, cement skin, grease and other impurities that can prevent adhesion. Adhesion and surface resistance of the substrate should be no less than 217 psi (1.5 MPa). Control joints, construction joints and cracks in the substrate which may be subject to movement after installation of CM 900 must be honored and maintained as joints in the new surface. If Calcium Chloride moisture testing of the substrate is to be performed, it must be done prior to the application of CM 900 as a false high reading will occur due to the tests being inaccurate on calcium aluminate leveling compounds. Always prime the substrate with PP 600 and allow to dry before pouring(see PP 600 datasheet for proper dilution and installation directions). In terms of the primer forming a film and the curing of the self-leveling, the temperature of the substrate must not fall below 50 °F. For best results, the ambient temperature in the work area should be between 50 and 77 °F. At higher or lower temperatures, the time for curing will shorten or extend. Protect the product from excessive heat, excessive cold and draft conditions during and after the installation. It is recommended that the installation should be done with a proper air ventilation from an HVAC system. With the risk for cracks due to shrinkage or settings in the subfloor, a concrete surface should not be leveled within the first 28 days after casting. As a recommendation the RH in the concrete should have reached RH 95 % as the upper limit for pouring the CM 900. Use the Combimix form foam for edging. In order to avoid drainage pipes from getting clogged, always make sure the drains are properly sealed before pouring.

Mix the dry powder with max 3.6 qt (3.4 L) of water, max 18 %, per 44 lb (20 kg) bag. Manual mix: Mix with a heavy duty ½” (13 mm), 650 rpm minimum drill and a whisk to obtain a lump free consistency. Mixing pump: Mixing pump intended for this purpose. Start pump at minimum of 120 gallons of water per hour and adjust as necessary to yield a self-leveling consistency. Please note that the production capacity and speed of the pump will dictate the gallons of water ratio per hour. Create the mixture with a drilling machine and a whisk, or a mixing pump intended for this purpose. The Combimix slump test must always be carried out to ensure the product performance and that the mixture is homogenized and free from separation. The correct water mixture can be tested using a slump test with a cylinder with Ø 1.18” and a height of 1.97” (Ø 30 mm and a height of 50 mm) on 11.8” x 11.8” (300 x 300 mm) plexiglas plate. With the correct water mixture, the spread should be max 4.92” (125 mm) for application thickness 1/4”–2” (6–50 mm). The slump test also checks that the material is well blended and that there is no separation.

The mixed material is applied by hand, or pumped out onto the substrate in lengths. Each new ribbon is added to the old one as soon as possible so that the material can blend together and create an even surface. The width of the ribbons can be adjusted to the capacity of the mixing pump and the thickness of the covering. The material requires a light treatment with a toothed trowel to provide maximum smoothness. Working time of the product is apx. 15 to 20 minutes. Application thickness 1/4”–2” (6–50 mm).

You can easily shape or cut the semi-hardened self-leveling underlayment material before it fully dries. CM 900 Industrial Base shall always be covered with CM 920 Industrial, CM 920 Design, CM 940 Industrial Top or CM 960 Industrial Super Top. The top layer can be applied after 12 hours if the guiding values regarding temperature, RH and air-flow is met. The guided time for dehydration down to RH 85 % of the product is 0.39” (10 mm) per week. The guiding value assumes a curing temperature of approximately 68 °F, 40 % RH and proper air flow. Newly produced surfaces must be protected against wind, sun and rain. When using PP 600 on top of CM 900 industrial Base always remember to prime two times (1:5 + 1:3) to prevent pinholes from forming.