Header Size for 8' window

I'm opening a window from my Dinning room into our family room, the opening will be roughly 4 ft. high and 8 ft. wide (opening completely on the interior of the home)

The openinh will be in a wall that is approx. 8 ft high and 12 ft. long now. I'll have plenty room for the header and to support both sides. The wall in constructed with 2x6 now, and it on the lower floor of a 2 story home.

My question is: What size header to I need to purchase?

Would I need 6x8 to span 8 feet? Could I sandwich two 4x6 together?

Thanks.

 

Generally, the taller the lumber, the more it will support. And headers usually aren't solid, but built up of 2by lumber. I wouldn't go with anything less than 8" tall lumber and use at least 3 2x8s with plywood glued inbetween. and REALLY 2x10s would be better since you have a second floor and roof about this. Also, you will need 2 cripple studs under the header on each side of the opening, so allow for that in calculating your final rough opening.

 

Yep, I have this. I just didn't know the header size.

So you say, 8" lumber, so seeing as the wall is already built with 2x6 studing, then I would need a 6x8 header.

If I can't find that, is 2 4x6 sandwiched legal?

 

I wouldn't use 2 4x6s.....you're setting the "4" in the verticle to get your 8" height......remember I said the taller the lumber the stronger, ....well the shorter, the weaker......doubling 2 4" thicknesses to get 8 is NOT as strong as a solid pc of 8" lumber standing up unless you do some serious ( not homeowner ) gluing techniques.

As I said, YOU DON'T HAVE TO USE a solid 6x8........Go get 3 2x8's.....that is 4 1/2" of the 5 1/2" you need to match the '6' of your 2x6 wall......then sandwich a 1/2" plywood plate 7" x8' between the outer and center of the 3-2x8s on each side and you pick up the inch you need PLUS you strengthen the header A WHOLE LOT....especially if you use some Liquid Nails instead of mayo in the "sandwich" This will take more weight than a solid 6x8 believe it or not.......

.....and my advice is use 2x10s instead of 2x8s.....remember you have a second floor + a roof up there.....better to over do it than under do it.

 

OK, thanks for all the great advise.