Joint grooving : Means making a groove along a joint between two floor coverings glued side by side. 2 types : Tight joint (less than 1 mm) for PVC flooring without foam and linoleum (Tarkett, Forbo) Wide joint (more than 1 mm) for foam-backed PVC acoustic and sports flooring (Gerflor) Homogeneous floors Heterogeneous vinyl floors Heterogeneous cushion vinyl, Compact Vinyl & Foam.