Framing an Upset beam?


ACADuser
 Share

Recommended Posts

2 hours ago, GeneDavis said:

Frame the openings with no header, and in the framing above, whether roof or floor, edit the end joist or rim arrangement to get the beef you need.  Or use steel.

I do it auto and then manually adjust the header size as its just to change the depth and the framing around it.

 

Link to comment
Share on other sites

Alan, if at all possible...  I would suggest as both Gene and Ryan have, and run the plates straight through - then place the header above as if it were a box beam. 

 

Continuous load paths are common requirements on the East Coast where home are constructed in the 140 mph wind zone. Believe it or not, that top plate is providing a tremendous amount of structural integrity.

 

That "break" in the plate is a known issue if the house gets hit w/ 100+ mph wind even though it's being shown as having strapping onto the king studs. If it’s not possible to upturn the header, then a section of steel angle iron would be the ideal solution. Like a flitch plate sandwiched between the 6inch dropped header. 

 

This would be a much better and stronger wall framing scenario: 

 

Snip20230817_23.png

  • Upvote 2
Link to comment
Share on other sites

You're quite welcome. If possible, keep the dropped header condition, but specify a 6" structural header. 

 

Flitch plate being the more common approach: https://www.betterheader.com/Beam-Legends

 

If the gravity load over that header is only rafters, a 6-8" beam should be fine. Again the main concern is that the wall loses integrity when the plates get cut out. A 50 mph wind only pushes on a window or door with about 5 to 7 pounds of force per square foot of area, whereas a 100 mph wind applies 20 to 28 pounds per square foot, and a 130 mph wind applies 34 to 47 pounds per square foot. Meaning that the wall is gonna want to flex. 

 

That's where the 'break' in the plate may not be ideal. If that were a floor condition rather than a wall, several people standing on the intersection of the header and the studs would eventually push the joinery apart (and that would be considered a low impact condition). 70 mph wind loads have ability to place over 1,000 to 2,000 lbs of force on an 8 foot wall with the 12 foot door. 

 

Please excuse over-explaining. (Structural engineering is my background).

All the best!

Link to comment
Share on other sites

Thanks for chiming in.

The link is very useful!

The wall is interior to a balcony with about 20' of flat roof tributary load.

The balcony is open with a roof.

We are in a 150MPH impact zone here in Tampa. (Exposure B  possible D)

12x8 window = 96 sf x 45 psf = 4320# / 2 = 2160# / 12' = 180 plf load on header/wall

Roof trusses 16" oc w/ H10A clips w/ 285# (f2) capacity. 285 x 0.75 = 213.75 # capacity

So the load is transferred into the roof diaphragm.

That was my thinking, :)

Headers are shown in red.

 

I'm looking at the steel flitch headers now.

 

Thanks again.

C1.JPG

C2.JPG

Link to comment
Share on other sites

All sounds good Alan.  It appears that you’ve got this well under control. The gravity load capability on the mini-flitch plates is pretty remarkable by the way. We’ve got a local source that specializes as you can see. 
 

They may have a minor degree of deflection though. Really small amount however. What we do is locate them right under the top plates, and then use a single or double 2 x to take into account any possible movement. Especially if there’s sliders involved. 
 

Good luck with your project! …and hopefully there won’t ever be any wind speeds that high. We’ve had a few major storms here on the island. They did so,e serious damage even though they were only Category 1 hurricanes. I tell folks to image their house driving down the highway as fast as a Ferrari. Needless to say, a stick framed structure will blow apart pretty quickly if it’s not held down right! 

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share