Abstract: A guide or fixture for use in the building construction trade includes a variety of features to allow the construction of decks, fences and the like to proceed more easily and quickly. The features include a flange which may be inserted between individual planks to provide for proper spacing of the planks, holes for proper positioning of nails or screws, a scale for linear measurement, and edges on one surface which serve as marking or cutting guides for the material used in such construction. One marking or cutting guide edge is preferably a 45 degree angle to the flange edge, thus allowing planks to be cut for diagonally patterned decks, fences or roof sheathing. The cutting guide edges, main surface, flange, and scale may be made in a variety of angles or dimensions in order to be useful with a variety of lumber sizes or deck or fence patterns.