Push 3/4″ backer rod between upper and lower sheets of poly. to create seal. Use only polyethylene backer rod from Copperstate Roofing Supply and our silicone as needed, to create a proper seal. Clean surfaces where silicone to be placed with rubbing alcohol. If sheets are longer than 12 feet use Big Stretch. Always lay initial bead of sealant and cap with same sealant after 72 hours. Briefly swipe surfaces where capping sealant to be placed with rubbing alcohol and let dry, prior to capping sealant.
