A method for installing a modular fireplace mantel surrounding a fireplace in a wall utilizing a unique leaf spring bracket. The leaf spring bracket for a modular fireplace mantel comprises a base plate, an upper lip, a lower lip, a left side lip and a right side lip attached to said base, said four lips defining a recess, a slot cut in the meeting edges of the base plate and the upper and lower lips, an extension attached to each of said left side and right side lips, each extension having one or more holes through which connectors may pass, an arcuate shaped leaf spring adapted to fit into said recess, both ends of said leaf spring having a reverse arc adapted to fit into said slots.