Patent ID: 8733065

Claim:
A method to install a floor comprising a plurality of rectangular floor panels laying in parallel rows on a sub floor with long and short edges which are connectable to each other along one pair of adjacent long edges and one pair of adjacent short edges, said panels having a mechanical locking system comprising a tongue and a groove for mechanically locking together said adjacent long and short edges at right angles to the horizontal plane of the panels, thereby forming a vertical mechanical connection between the panels, and a locking element at one first long edge and a locking groove at an opposite second long edge thereby forming a first horizontal mechanical connection locking the long edges of the panels to each other in a direction parallel to the horizontal plane and at right angles to the joint edges, each panel at said adjacent long edges being provided with a second horizontal mechanical connection locking the panels to each other along the joined long edges in a direction parallel to the horizontal plane and parallel to the joint edges when the panels are laying flat on the sub floor, said second horizontal mechanical connection comprises local protrusions arranged in a pattern that repeats in a direction along the joint edges in said mechanical locking system on the long edges which reduces displacement of the panels in a direction along the joint when the panels are laying flat on the sub floor and are locked with the vertical and the first horizontal connections, the method comprising: installing a first panel on a sub floor in a first row, bringing a second panel in a second row into contact with its long edge against the long edge of the first panel and held at an angle against the sub floor, bringing a new panel in a second row at an angle with its long edge in contact with the long edge of the first panel and its short edge in contact with the short edge of the second panel, displacing the new panel against the second panel in the angled position thereby bringing the tongue into the groove until the top edges at the short edges are in contact with each other, angling the second and new panels down to the sub floor thereby locking the long edges of the second and new panels to the first panel in a vertical direction and in a first horizontal direction perpendicular to the joined long edges and in a second horizontal direction along the long edges whereby the locking in the second horizontal direction prevents separations between the short edges of the second and the new panel.