A site sanded floor is not suitable for wide plank installations. When a site sanded floor is installed filler is applied to the joints. Wide plank floors need to be able to compensate for changes in humidity which cause minor expansion and contraction in each plank. If filler is applied to the joints of a wide plank floor or even some narrow plank floors the filler can fall out when the wood shrinks even a microscopic amount. Ecofir floors avoids this problem by providing a micobevel which effectively hides expansion and contraction of wider boards without the need for filler.