Single component polyurethane solvent-free primer Single component polyurethane moisture-cure primer that is water and solvent-free for treating subfloors before laying wood floors. The low level viscosity and the excellent penetration make it ideal for strengthening and waterproofing concrete and anhydrite screeds with a high level of moisture up to a maximum of 5% M.C. (up to 2.8% M.C. with just one coat). It is recommended especially for screeds with built-in heating. Moreover, the absence of solvents makes it safe for transportation and storage (nonflammable product) and when applied (odourless, it can also be used in the vicinity of rooms that are in use). Compared with products containing water, PRIMER SF offers a much higher coverage and does not increase the humidity of the screed.