Pecora PCS Contractor Silicone is a one-part, neutral cure, medium modulus silicone sealant designed for moving joints in exterior window and door perimeters, concrete panels, tilt-up panels, curtainwall and EIFS. Questions?Contact us
Joint Design: Proper sealant dimensions are critical when installing elastomeric joint sealants. Generally, a sealant width- to-depth ratio of 2:1 is recommended. Dynamic joint conditions will require a minimum 1/4″ width and 3/16″ depth in order to maintain the sealant’s movement capabilities. For joints greater than 1″, consult Technical Services.Lap shear joints should have a bead width which is equal to or greater than the total anticipated movement. Small curtainwall panels and lites should allow a minimum width of 1/4″ (6 mm) for the sealant bead. Larger panels for which a great deal of movement is expected should allow a minimum width of 1/2″ (12 mm) for the sealant bead. Glazing of plastic lites and panels fabricated from plastic require larger than usual joint dimensions due to the plastics high coefficient of thermal expansion.The width of building expansion joints varies because of seasonal and daily changes in temperature. If PCS cannot be installed when the design width is approximately halfway between the dimensional extremes, the designed joint must be at least twice the total anticipated joint movement. Good architectural practice calls for joint design of four times the anticipated movement due to con- struction tolerances and material variances.
Surface Preparation: Clean all joints and glazing areas by removal of foreign matter and contaminants such as oil, dust, grease, frost, water, surface dirt, old sealants or glazing compounds and any protective coating. Porous substrates and precast concrete panels using form release agents other than polyethylene film should be cleaned by grinding, saw cutting, blast cleaning (water or sand), mechanical abrading or a combination of these methods which will provide a sound, clean and dry surface for sealant application. Dust,looseparticles,etc.