The coefficient of friction, μ, between EPS geofoam is 0.5 along molded faces. It is higher along cut faces where there is increased roughness. The coefficient of friction for a wire cut face can be assumed to be the same as a molded face or 0.5. If yellowing of the block surface occurs due to UV exposure, the block should be brushed to remove the residue and a coefficient of friction of 0.5 can be used.