For windows that span 36 inches or less, use two two-by-fours or one four-by-four. Since many windows are in the 24-inch to 34-inch range (width), this is a commonly used window header size.

What size header Do you need above a window?

If you are creating an opening no wider than 4 feet, for a door or smaller window, then you need a 2-by-6 header. If you are putting in an opening between 4 and 5 feet wide, then you’ll need two 2-by-8 headers. If the opening will be 5 to 6 feet wide, such as for double doors, then you will need two 2-by-10 headers.

How wide should a window header be?





Header size required to support the roof, ceiling and one center bearing floor of a 28-ft. wide building; 30-lb.



Figure B: Example of Calculating Header Size.

Header Size Maximum Span Number of Trimmers
Double 2×6 4 ft., 0 in. One
Double 2×8 5 ft., 0 in. Two
Double 2×10 6 ft., 2 in. Two
Double 2×12 7 ft., 1 in. Two


How do I know what size header I need?

It went like this: Measure the span in feet and add 2 to that number. The sum will be the height of your double header in inches. For example, if the span is 4 feet, add 2 to 4 for a sum of 6. Therefore, the header would need to be made from doubled 2x6s.

How wide can a header be?

How far can a 4×12 header span:- as per general rules and guidelines, nominal size of a 4×12 header can span upto 12 feet. Thus, 12 feet is maximum allowable span for 4×12 size header. Therefore, for a span upto 12 foot, you needed 4×12 size header. 4×12 size header is needed for a 12 foot span or opening.

What size header do I need for a 36 door?





A typical header width with single jack studs is cut 3″ larger than the rough opening. An example: A 36″ door has a rough opening width of 38″ so your header is cut at 41″.

How wide can a 2×10 header span?

How Far Can a 2×10 Beam or Header Span? A 2×10 beam – made up of two 2x10s nailed together – can span up to 11′ without support beneath a deck that is 4′ wide. For a more normal-sized deck, the same beam can span 8′, supporting a deck that is 8′ wide.

How far can a 2×12 header span?

12 feet

A double 2×12 beam can span 12 feet; a (2) 2×10 can span 10 feet and so on.

How do I create a header in windows?



Quote from the video:
Quote from Youtube video: This letter J represents Jack and the jack is the framing member that holds the header up next I'm gonna strike some lines perpendicularly. Across these plates.

Do windows need a header?

Most window and door openings don’t need typical headers resting on jack studs. Non-bearing wall openings less than 8 ft. wide don’t need any header. So on the gable ends of this house, we just installed king studs and a flat head board.

How far can a 2×6 header span?

A double 2×6 header can span between 2′-1” and 6′-0” for exterior walls depending on building width, snow load, number of floors, and location and number of bearing walls.

Can a 2×6 span 14 feet?



What is this? A 2×6 rafter can span 14 feet 8 inches when spaced 16 inches apart with No. 1-grade southern pine lumber on a roof with a 3/12 slope or less with a maximum live load of 20 pounds per square foot and a dead load of 15 psf.

How far can you span a triple 2X10 header?

A triple 2×10 header will span 11′-5” and 6′-7”, and a 4-ply 2×10 header 13′-3” and 7′-8” in similar structures. Adding a second floor decreases the spans as it increases the loads. A doubled 2×10 can span 5′-11” and 3′-7” for 12′ or 36′ building widths.

How far can a triple 2X8 header span?

Depending on various factors, the maximum span for a 2×8 floor joist is 16′ 6”. The maximum span for roof rafters is 23′ 9”. For headers, the maximum span is 11′ 2”.

How wide can a 2X8 header span?

In general, a 2×8 will span 1.5 x 8, so 12-feet. Based on all factors though, a 2×8 joist span is 7′-1” to 16′-6”, and a rafter 6′-7” and 23′-9”.

How much load can a 2X8 support?



Weight supported by a double or triple wood headers.

Span (feet) Weight Supported (lb)
2 x 2″ x 6″ 3 x 2″ x 8″
4 2250 5850
6 1680 4690
8 3990

Can I use 2×8 for deck joists?

2×8 for joists will be fine, with 16″ OC. Should use 2×10 for beams but 2×8 will be fine as well. If you are worried you can triple the 2×8 for the beams but double will be sufficient. You should put the beams at 7 and 14 feet out from the house, with the piers you should do 3 per beam with spacing of 1, 7, 13.

Does double joists increase span?

For example, if you double the thickness or number of joists in a floor, the distance the boards can span will increase by approximately 25%. But if you double the width of the boards, the distance the joists can span increases between 80% to 100%, even though you’re using the same board feet of lumber.