Window Installation for a Steel Wall

Framing Window Openings in Steel Stud Walls

• As with wood-framed window openings, steel wall window openings consist of a horizontal header along the opening's top and a horizontal sill plate across the opening's bottom, with vertical studs at each of the opening's sides. Below the sill and above the header, short studs called cripple studs support loads and provide a nailing surface for interior and exterior wall coverings. Builders often use a set of two studs on either side of exterior window openings in steel walls.

L-Headers

• L-headers are broad, angled metal plates that span across the top of a window opening in a steel wall. Unlike conventional lumber headers, which form the top side of a window opening's perimeter, L-headers attach to the steel stud wall's top plate, and a bent stud forms the top side of the window's opening.

  L-headers are manufactured to precisely fit over standard steel framing materials. Builders simply trim the L-header, align it over the window opening and fasten it to the steel stud wall with sheet metal screws.

Built-Up Steel Headers

• Similar to the site-built laminated headers of wood-frame construction, built-up steel headers consist of several steel framing members joined face-to-face. The laminated steel members are strong enough to support and transfer loads over window openings, and may span across the top of the opening or beneath the wall's top plate.

  Built-up steel header specifications vary according to a project's requirements. Consult an architect, engineer or building authority before constructing a built-up steel header in a load-bearing wall.

Lumber Window Frames in Steel Walls

• Some building projects employ hybrid wall construction systems that use both wood and steel framing members. In hybrid systems, a stud wall frame may consist of steel studs, while track and window and door openings consist of wood studs and headers. Builders might anchor a window or door's jack and king studs to steel tracks via end-nailing. Alternatively, builders might anchor a lumber header between steel studs with metal brackets.

Attaching the Window to the Frame

• With a steel or lumber frame in place, builders hoist the window into its opening and align its vertical and horizontal position with layout tools and shims. Builders fasten windows to steel frames with sheet metal screws and to wood frames with wood screws.