Investcorp has agreed to sell Icopal to GAF for roughly €1 billion. Founded in 1876, Icopal provides high-end roofing and waterproofing products and services across Europe through an array of brands. Investcorp had purchased the company for €850 million in 2007. The acquisition by GAF, a North American roofing manufacturer, will create a combined business with nearly $4 billion in sales across more than 80 countries. The transaction is expected to close 2Q.