Header — Structural Beam Above Wall Openings Guide

A header is a structural beam above a door, window, or other wall opening that carries loads around the opening.

Header diagram — labeled parts, dimensions, and installation context

What It Is

When a wall opening interrupts studs, the load from above still has to be supported. The header spans across the opening and transfers that weight to jack studs or other framing at each side. Headers may carry roof, ceiling, floor, or wall loads depending on where they are located. Exterior walls and bearing walls usually need larger headers than nonbearing interior partitions.

Types

Common header types include built-up dimensional lumber headers, engineered wood headers such as LVL, steel headers, and insulated headers used to reduce thermal bridging in exterior walls.

Where It Is Used

Headers are used above windows, exterior doors, garage door openings, pass-through openings, and any framed opening in a load-bearing wall. They also appear in remodels when new openings are cut into existing structure.

How to Identify One

You usually identify a header during framing or after finishes are removed. Signs of a problem include sagging above an opening, drywall cracks at upper corners, doors that rub, or a window that becomes hard to operate.

Replacement

Replacement or reinforcement is needed when a header is undersized, damaged by rot or insects, or altered during remodeling without proper support. Because headers are structural, repair design and temporary shoring should be handled carefully and often require a contractor or engineer.

Header — FAQ

What does a header do in a wall?

A header bridges over an opening and redirects the load to framing at each side. Without it, the wall above a door or window can sag, crack, or fail to support the structure properly.

Does every window and door have a header?

Most openings in bearing walls do, but size and design vary. Some small openings in nonbearing walls may use lighter framing because they are not carrying the same structural load.

What are signs of a bad header?

Common clues include diagonal cracks at the corners of openings, a bowed wall section above the opening, sticking doors, or visible sagging. Those symptoms can have other causes too, so structural diagnosis matters.

Can a header be replaced from inside the house?

Yes, but it is usually a significant structural repair. The wall often has to be opened, the load temporarily supported, and the new header sized correctly before finishes are restored.

Is a header the same as a lintel?

They are similar in function because both span openings and carry load. In residential wood framing, 'header' is the more common term, while 'lintel' is often used for masonry or steel spans.