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4x6 yellow pine header ?

Started by yetti462, September 27, 2023, 02:40:31 PM

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yetti462

I'm adding a porch to my house.  I'm having trouble getting 4x8 for the headers that support 4x6 rafters.  Can I use 4x6 yellow pine as a header?  
Biggest span will be 8'.  These will be sitting on top of 6x6 posts.  the 4x6 rafters will be on 4' centers.

Ianab

Can you get a pair of 2x8" and sandwich them together, effectively creating the 4x8 that the plan calls for?
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

yetti462

I've thought about doing that.  It wouldn't match up on looks as well if my only hesitation.

Jim_Rogers

Quote from: yetti462 on September 27, 2023, 02:40:31 PM
 Can I use 4x6 yellow pine as a header?  
Depends on the load on the roof.
Jim Rogers
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

beenthere

Sandwich three 2x8's and add plywood spacer enough to match the 5½" of the 6x6 post. Plenty of strength then and will look great.

If the "look" of laminated is the problem, then cap the laminates with a trim board. Very few onlookers will be the wiser. 
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

yetti462

I did find some 5x7 white pine beams or other thought is get some oak beams sawed.  

Don P

As compared to southern pine, you would be backing up. White pine is half strength, mixed oak is 2/3 the strength of SYP in bending.
Fb #2 mixed oak =800 psi, same in SYP is 1200 psi, EWP is 575.

At an 8' span for a 4x8 header and white pine is available to you, I sense a snow load.
Let's start over, what have you got for the horizontal measure of the rafter span, how much overhang is there and where are you?

yetti462

The original rafters are 11'ish.  The deck I'm covering is 8'.  I'll measure the overhang tonight.  I'm in southern Indiana, not as much snow as years past.  The White Pine is only available b/c it's from Menards.  

Don P

Let's call it a 2'. Using the hazard tool from the stickies at the top of the page it looks like you're in ~20 psf snow country, which is minimum for wind anyway. Call dead load (material weight) 10 psf and we are at 30 lbs per square foot. Half of the 8' span is bearing on the house, half is on the header, so 4' plus the overhang, call it 2'  so 6' of width times 8' of header span = 48 square feet tributary to the header x 30 lbs per square foot =1440 lbs total design load.

Go here;
Design for Bending (forestryforum.com)

I'm getting a pass at 4x6 in #2 SYP

yetti462

So in a "Pass", you pass it as approve? or Pass and go bigger?  nevermind, I just input numbers and looks like a PASS!!

Don P

Now some caveats with a few more minutes of thinking. you said 4' centers on the rafters, that isn't really a uniform load. If a rafter lands at midspan the bending force doubles. If you use 4x6's pick the best for the worst places. I've never used a header this light for more than ~3' of window header. I really prefer the built up double or triple 2x8 ideas above  :).

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