SPF does not need fasteners to hold it in place, it attaches chemically to the surface that it is sprayed to. This eliminates damage (piercing) of waterproof membrane by metal fasteners.
Spray Polyurethane Foam: Provides a seamless area of insulation and seals cracks and crevices. Insulates and waterproofs in tight areas and hard to reach areas.
No gathering of water in cove footing area (at base of the foundation). Will not settle, adds structural strength, helps to prevent structural foundation cracking, seals cracks and crevices from unwanted odor and gas penetration.
SPF stops moisture driven elements due to its solid nature and sealing abilities. Applied over the SPF is a black polyurea (bed liner spray) for a hard shell protective coating to double the blockage of water and protect the foam from damage.