pieces after cutting being transferred to a factory or workshop for machining what is here said about designing of the connecting means on the floorboards is applicable in appropriate parts also to the fitting pieces if the fitting pieces are only provided with a groove 9 and if a loose tongue 10 is used as shown in fig9 c for joining by means of glue or with a loose tongue 10 which also constitutes a mechanical joint system according to fig9 d the number of fitting pieces in the assortment can be reduced significantly since these fitting pieces can then be mirror inverted in the preferred alternative the number of fitting pieces can be reduced to four different fitting pieces marked in fig9 with 14 15 16 and 17 a factory made groove with a loose tongue may facilitate installation significantly since the vertical position of the groove in relation to the surface of the floorboards can be obtained with greater accuracy than is allowed when using for instance hand tools the loose tongue 10 may consist of for instance an extruded section of plastic or aluminum it can also be made by machining a suitable wood fibre based board wood material or the like the loose tongue 10 shown in fig9 d constitutes both a vertical and a horizontal locking means.