Save the file as WoodFloor.pat and put it where AutoCAD can find it.
Here is the pattern file, and you will notice that at the end, instead of a blank line, one can put a line starting with a * and then one can put a credit for the creator. Download and install more than 500 kinds of AutoCAD Hatch Patterns 2d dwg for free, including tile, wood, water, stone, floor, paving stone, lattice. 25 AutoCAD Wood hatch patterns for free download, (no registration required) the selection includes Plywood hatch patterns, end grain, ash, hardwood, Floor. One cannot have a completely random hatch pattern, but if the repeat spacing is large enough, the eye can get fooled. AutoCAD Hatch patterns free download CADBlocksDWG.
It is based on a plank width of 150 drawing units, and lengths to suit your picture. I had a quiet afternoon so I wrote a pattern file for a Wood Flooring Hatch.
