A header is a single member composed of two or more wood members, securely attached together and used to transfer loads above openings. Headers are used to create openings for windows, doors, and interior passageways. They serve a significant structural purpose. Since windows and doors cannot support weight other than their own, the weight of above these opening must be collected and redistributed to adjacent studs. The depth of the header is determined by considering the weight from the structure above and the width of the opening.

Solid Sawn Headers
A grademark identifies the species, grade, grading agency, and mill number. This information allows the product to be traced to the mill of origin, as well as establishing the structural properties of the piece of lumber.
Most 2x4 dimension lumber is visually graded and marked with an ink stamp at the mill. The markings on this bunk of lumber provide information to ensure the product has the strength for the application.
Bay window headers support a small roof. An LVL header in the foreground supports the floor joists above and the exterior wall and roof.
Headers are revealed in exterior and interior wall framing. Where interior walls are non-load bearing, headers are not required.
A long-span header is used to carry load across a complex window design.
LVL Headers
Laminated Veneer Lumber is an engineered wood product created by layering dried and graded wood veneers with waterproof adhesive into blocks of material known as billets. Cured in a heated press, LVL is typically available in various thicknesses and widths and is easily worked in the field using conventional construction tools. LVL is also known as structural composite lumber (SCL).
The exterior cutaway reveals the window header beneath the brick and wall sheathing.
I-joist rafters are blocked at the point which they bear on exterior wall headers. The blocking assures the that the I-joist cannot rotate from their upright position.
Laminated veneer headers are commonly used to span large openings, such as this window opening.
Pitched chord roof trusses are attached to the wall top plate and header with metal connectors.
PSL Headers
Parallel Strand Lumber (PSL) is a high-strength structural composite lumber product manufactured by gluing strands of wood together under pressure. It is a proprietary product marketed under the trade name ParaIlam®.
Parallel Strand Lumber (PSL) is available in a variety of shapes for use as columns and girders.
LSL Headers
Laminated Strand Lumber is an engineered lumber product made with a network of hardwood strands laminated together with a waterproof adhesive to form a single, solid, wood member. LSL sections are precision-cut into standard section components making them suitable for use as short and intermediate span beams, lintels, purlins, columns, and rim boards in residential and light commercial applications.
Once the exterior wall sheathing is attached, the exterior wall framing is no longer visible. This typical framing drawings details how headers and walls studs are used to construct an exterior wall.
The exterior cutaway reveals the window header beneath the brick and wall sheathing.
Glulam Headers
Glulam is a stress-rated engineered wood product comprised of wood laminations, or "lams," that are bonded together with strong, waterproof adhesives. Glulam components can be a variety of species, and individual "lams" are typically two inches or less in thickness. ANSI/AITC A190.1 includes requirements for sizes, grade combinations, adhesives, inspection, testing, and certification of structural glued laminated timber products.