The present disclosure relates to a hollow board 1 with first and second main surface layers 3, 5. A plurality of distance elements connecting the first and second main surface layers and maintain a predetermined distance there between. The main surface layers include at least a layer of high-density fiber, HDF, board, and a plurality of distance elements are distributed in the space between the main surface layers, and at least some comprise at least one elongate HDF board strip 15 which is oriented such that its longitudinal edges interconnect the first and second main surface layers 3, 5. The HDF boards of the surface layers and of the at least some of the distance elements comprise wood particles bonded by a resin including an isocyanate, such as methylene diphenyl di-isocyanate, MDI.