The size of a door header depends on whether it's for an interior or exterior door, and the type of lumber used.
A door header's main job is to transfer the load from above the door opening to the wall studs on either side. The length of the header is determined by the width of the door opening plus the width of the studs it will rest on.
Here's a breakdown:
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Interior Doors: Generally require a header of either 2" x 4" or 2" x 6".
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Exterior Doors: Require a minimum header size of 2" x 10".
The specific dimensions can vary based on local building codes and the load-bearing requirements of the wall. It is important to check local building codes to ensure proper sizing. The header is generally attached to wall studs on each side and supported underneath by additional studs (often three).
