Header
Affiliate link — we may earn a commissionA header is a horizontal beam above a window or door opening in a framed wall. It carries the load from above the opening and transfers it to the studs on either side (called jack studs or trimmer studs). Headers are typically built from doubled 2x lumber, engineered LVL (laminated veneer lumber), or steel. The header size depends on the span of the opening and the load above it. A 3-foot door in a non-load-bearing wall might only need a flat 2x4. A 6-foot window in a load-bearing wall might need a doubled 2x12 or an LVL beam.
Why It Matters
If you're cutting an opening in a wall for a new window or door, you need a header. Skipping it or undersizing it transfers the load to the drywall and trim, which can't carry it. The wall sags, the door sticks, and the drywall cracks. Get the header right before you close up the wall.