Black Diamond Seal-coating has the knowledge and experience to handle any size job. We are big enough to get the job done but small enough to still give personal, one-on-one service and that is important to us. We can perform regular pavement maintenance, which can double the life of your asphalt, saving you thousands in replacement costs. We service all of the greater Portland Metro Area. Give us a call we would be happy to give you a bid for your project.