Patent ID: 8291606

Claim:
A guide tool for use by a mason in laying concrete blocks or bricks to form a wall which includes a door frame having a vertical door frame jam, said guide tool being configured especially for slidably movable and position-retaining snap-fit manual attachment to the jam of the door frame in order to proximally position a span of mason's line, said guide tool comprising a body sized and configured to removably embrace and slidably attach by snap-fit engagement to a door frame jam for position-retaining on the door frame even in the absence of tension in the mason's line, and for manual forceful movement vertically along the door frame jam, and further said guide tool providing for securing said mason's line relative to said door frame jam at a desired position both of selected elevation and also in plan view with a selected horizontal offset of the mason's line relative to a face of the door frame jam, whereby the mason's line when secured at the door frame jam via said guide tool at the proximal end of a span of mason's line and at a distal end being secured to truly vertical “truth pole” having a desired location in plan view said span of mason's line provides a true positional reference in both elevation and plan-view for laying of concrete block or brick in a course extending from said door frame toward said truth pole, both with respect to an intended line of the wall in plan view, and with respect to the desired horizontal line of a course of block or brick forming the wall.