Underfloor Requirements Keep to Expansion Distances: Topflor is a natural product. The underlay is wood, which lives and works, depending on the time of the year. This is why it is necessary to consider expansion joints, i.e., a distance of 8 mm between all fixed elements which jut out of the floor e.g. walls, pillars, door thresholds, heating pipes and other fixed constructions. <-8mm-> .. Please use Topflor expansion spacers to ensure these distances are maintained. Between two rooms and in all rooms where the surface to be covered is larger than 80 m2, there should be 2 cm expansion joints. The same goes for rooms where the surface to be covered is longer than 10 m (floor panels laid lengthwise) or wider than 8 m (floor panels laid crosswise). Next - Masking Expansion Joints