Sikalastic-612 is a single component, cold applied, moisture-triggered polyurethane membrane. Sikalastic-612 cures to form a seamless and durable waterproofing solution for exposed roof areas and structures. uses. Waterproofing of flat and pitched roof structures. Treatment of new construction and refurbishment of existing structures. Sikalastic-612 applicable to existing concrete, asphalt, roofing felt, brickwork, asbestos cement decks (subject to condition and priming requirements).