Abstract: A construction tool and method for its use in laying out stud marks. The tool is adjustable and is especially suited for laying out stud marks on a rafter of a pitched roof so as to be aligned with the corresponding stud marks on a sill beneath the rafter. The tool includes an elongated measuring member; stud-marking members attached to the measuring member in spaced, transverse relation therealong, at least one of the marking members being adjustable along the measuring member; measurement indicia on the measuring member that enables the spacing between the marking members to be set; and conversion indicia on one or more of the members that sets forth the relationship among various roof rises and stud spacings on sills and rafters. The method involves laying out markings on the sill and rafter boards with the tool including the steps of placing the layout tool along a first of the boards, e.g.