Construction companies working in Qatar say that they are starting to feel the supply chain impact of the trade restrictions imposed by Saudi Arabia, Bahrain and the UAE...Contractors estimate that about half of Qatar’s building material and equipment are imported and if the embargo continues it will have a major impact on their ability to deliver projects and as a result there could be years of litigation....“Bitumen is the big worry at the moment,” says an international contractor working in Doha. “Most of Qatar’s bitumen comes from Bahrain, and they have now stopped shipments. Some contractors are sitting on a stockpile and will be ok for a while. Those that were relying on new deliveries have problems already.”...Bitumen is a primary product used in road construction...[T]here are over $18bn of major road schemes under construction at the moment in Qatar. If the shortages persist Qatar will need to find alternative sources of bitumen from other markets if these projects are to progress as planned.