A method comprises selecting a mounting bracket having opposite horizontal, parallel wings, and a raised portion between the wings, applying a coating of an uncured first sealant material to a first area of a roof surface above decking of the roof, the first area having an outer perimeter greater than overall area of the bracket, urging undersurfaces of wings of the bracket into the uncured sealant material, securing the mounting bracket to the roof by screws applied into the roof decking through holes provided in the wings of the bracket, and applying a second sealant material over heads of the screws on upper surfaces of the wings of the bracket.

A method for mounting a fixture on a membrane-covered roof involves a bracket with wings coated on upper surfaces with a material rendering the wings heat weldable to roofing membrane. The bracket is placed on the roof membrane, and a transition membrane with a cutout for a raised portion of the bracket is placed over the bracket and heat welded to both the upper wing surfaces of the bracket and to the roof membrane.

An adaptor for connecting a ground screw to an upright beam of a solar panel support assembly includes (a) a cylindrical connector having an open ground-screw receiving bottom end and a top end, the cylindrical connector having an inner circumferential surface with a diameter slightly larger than that of the ground screw and at least two sets of bolt holes, each set of bolt holes including at least three bolt holes uniformly distributed circumferentially about the cylindrical connector at an axial level, and the at least two sets of bolt holes being axially distanced from one another; (b) an intermediate plate having a top surface and a bottom surface fixed to the top end of the cylindrical connector; and (c) an upright beam connector fixed to the top surface of the intermediate plate and extending upward from the intermediate plate.