Neither code has (3)2×6’s in it’s tables of header spans, so an engineer seal on the header design would be required to do anything that’s not on the tables. In the plans it calls for a tripled 2×6 beam sitting on 4×4 posts to support the roof. None of the span tables I find say anything about triple 2×6’s and I’m not sure if double 2×8 would be equivalent and how much bigger I need to go to support the additional span since it’s a porch roof. Does anyone know where I can find a header span table?
We’ll explain how headers work and give you some tips on how to design the opening so it supports the weight of your house. The longer the distance a header spans and the heavier the load it supports, the more substantial it needs to be. Double 2×6, 4 ft., 0 in. I have been unable to find detailed span tables online, but I’ve been able to extract this info from various sources: for a double 2×4 header, I the max span is 4 feet, and for an 8 foot span I need a double 2×8. My question is, what is the max span for a TRIPLE 2×4 header with a bottom 2×6? Use these tables to establish lengths, sizes and spacing of rafters based on a range of factors such as, grade, spacing and pitch. Rafter Span, Roof Beam Span, Ceiling Joist Span, Floor Joist Span and Floor Beam Span. 2-2×6. 2-2×4. 2-2×6. 2-2×6. 2-2×6. 2-2×6. 2-2×6. 2-2×6. 2-2×8. 2-2×8. 2-2×6.
The code tables call for double 2x’s for headers, advanced framing suggests one. Typically if you are going through the trouble of doing advanced framing you are going to increase to a 2×6 wall from a 2×4 wall anyway – you can still use the double header and have room to add insulation. What size headers do I need for a 8′ span is it 2×8 or 2×10? The allowable spans for nominal 4-inch (102 mm) single headers and 2-inch (51 mm) double headers in load-bearing walls shall not exceed the spans set forth in Table 602. TABLE 602.7 MAXIMUM SPANS FOR HEADERS LOCATED OVER OPENINGS IN WALLS (feet) SIZE OF HEADERa,bHEADERS IN BEARING WALLSbHEADERS IN WALLS NOT SUPPORTING FLOORS OR ROOFS Supporting roof and ceiling onlyOne story aboveTwo stories above 2 2 x 44 2 2 x 664 2 2 x 886 10 2 2 x 10108612 2 2 x 121210816 For SI: 1 inch 25. For header spans see Tables R502.5(1) and R502.5(2).
How To Build Window Headers And Door Headers