Putting in two small windows as part of our kitchen remodel (21" x 31").

They are going in an exterior gable wall, framed with 2x6's. I can't get a straight answer from anyone about what "size" header I should put in! Do I have to use 2x10? Or would 2x6 be fine?

Also, any input on how to construct the headers themselves? Should I build hollow and insulate, or actually build solid ones with three 2x's and some sheets of 1/2" plywood to equal 5 1/2"?

Last related question: should I install a double sill plate in this scenario or is a single sill plate sufficient?

I have include two diagrams below. The first shows how I plan to frame out the main openings (implementing a double sill plate). The second diagram shows how I plan to rough in the actual window openings which are represented by the grey areas.

Main Openings

Window Openings

This is how it ended up. Hope it speaks for itself and thanks to everyone for their input.

enter image description here

  • In your second picture you show only one stud on one side of each of the narrow window rough openings. You will want to change that to have two studs on each side of the rough opening. This provides the necessary backing for nailing in siding, drywall, interior casing and exterior casing adjacent to the sides of the window. One thickness of framing member is usually not enough for this.
    – Michael Karas
    Apr 28, 2016 at 22:31
  • @Michael Karas Pictures have been updated. I added a 2x6 underneath the 2x10 header boards as well as the second stud to the outside of the window openings as you suggested. Good catch! Apr 28, 2016 at 23:00
  • Lot of extra wood for two small windows ehh.
    – Michael Karas
    Apr 28, 2016 at 23:44

1 Answer 1


It's hard to provide a "straight answer" with the information given. Bearing wall vs. gable wall, rambler vs. two-story. Window position and wall height. There are many factors. I can tell you that triple-member headers are not common except where limited height is available.

We built nearly all our exterior headers with doubled 2x10s in a U configuration, with insulation between. This leaves no voids when drywalling, hanging window treatments, mounting exterior trim, etc., and we know they're adequate from a structural standpoint. It's only when dealing with spans over 5 feet or so that you start looking to LVL headers.

When in doubt, and when there are no drawbacks other than a little initial cost increase, go with the bigger option.

  • Updated my question with better info. Sorry I wasn't more specific! Apr 28, 2016 at 22:11

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.