Best way to make a doorframe/window header?

Question

I'm making a shed with a 2x6 frame and unfortunately can't cut 4x6 or 6x6 boards to use as single piece headers (as I'd need a chainsaw or something which I don't have). I was hoping to use 2x6 boards place long ways up and placing several side-by-side. Unfortunately doing so either makes the header 1" to narrow for the frame (with three boards) or 1/2" to wide (with four boards). I know that if I placed them long ways flat and stacking several it would fit, but I didn't know if you could do that and still keep the header from sagging.

Answer 1

The common way is to add spacers 1/2" plywood ,osb or anything that can take up the space. Rip the (plywood) to just a little thinner than the 2x6 say 5 and 1/4" and carefully sandwich the plywood in the centers untill it measures 5 and 1/2 inches. This should be 3 peices of 2x material and 1inch of filler.

Answer 2

You're right in that you must set them up on edge for bending strength. Use 3 of them, with 2 pieces of 1/2" plywood sandwiched in between. Like this

2x6-plywood-2x6-plywood-2x6

Cut the plywood 5 1/2" wide and the same length as the 2x6s and glue and/or s***w them together (this technique is called "sistering" them).

For a 2x4 frame, you use 2 2x4s and 1 piece of plywood in between.