• Joint movement capability of a sealant is determined by the percentage of movement between the substrates to be sealed. Narrower joints provide less movement than wider joints.
• Good architectural practice calls for joint design of four times the anticipated movement due to construction tolerances and material variations.
• Use joints greater than the minimum of .25”, since wider joints can accommodate more movement than narrow joints and can also result in a greater joint spacing.
• Use a sealant backing or bond breaker tape to eliminate “three-sided adhesion.” The sealant should bond only to the substrates that will be moving.
In joints up to 0.5”use a 1:1 width to depth ratio and joints wider than .5” use a 2:1 width to depth ratio to accommodate movement.
• For a joint size larger than 1 inch, the depth should be kept to between .375” to 0.5”.
• Excessive sealant depth will result in compromised sealant movement capability.
• A sealant joint should not be greater in width than 2 inches without consulting Pecora Technical Service department.
• The number and spacing of joints is critical to performance.