i-Form is IPEX's own alternative to building lead, which is used as a water barrier in the connections of roofs and facades. These water barriers used to be made of lead. We offer i-Form instead, a rubber-based EPDM. EPDM is a waterproof, flexible and environmentally friendly rubber that is easy to process and has a longer lifespan than lead. Reasons enough to use i-Form in stead of lead!