FS201 | 2lb Foundation Spray Foam Have you ever sealed an exterior basement wall with tar? If so, then you know what a tedious, time-consuming, and messy job it can be. For those looking for an easier way to seal exterior foundation walls, HMI now has the perfect foam for you. FS201 is a 2 lb per cubic foot polyurethane foam that has been formulated especially as an exterior foundation wall spray. It was developed to have a fast reaction time to avoid dripping when sprayed. It also provides a moisture barrier for foundation walls, seals all cracks, and provides a waterproof foundation. Best of all, it replaces the need for tarring. With FS201 foundation wall spray, foundation wall sealing can take as little as one hour compared to an entire day using tar. Before Foundation Spray During Foundation Spray Complete To see this foam in action check out the video below!