How high can I go with this bent's cross beam, it is key tenoned?

[Justin Bailey]

I'm building a rather large firewood shelter using mostly 6x6 and 4x6 PT wood. There are 5 bents w/ 12' post spacing, a 12ft braced cross beam connecting them. The front post is 1' taller to create a slope on the single pitched roof, and I am having trouble with how high I can put the cross beam because the longer plates that join the bents are also braced, and I would like to have the cross beam level. This means I may have to get longer braces for the front plates, and use shorter ones for the back. I want to use wedging keys I made from cumaru, and don't know how close I can go to the top of the rear post top. The three posts in the center I have made a splined dovetail joint and the end posts are just a half dovetail tenon going through a mortise in the plate, secured with a wedge. There will be 16' 4x6's pitched atop the plates at 4' intervals with 2x4 strapping then 16' corrugated sheet steel roof. I also will peg braces and splines w/ 3/4" locust pegs. 4x6 roof rafters will be notched to the plate and screwed w/ 8" screws.

  

  

  

  

 

[Justin Bailey]

The bents are 16' apart, I know the 6x6 is marginal to say the least. I will try to rely on the bracing and install bow up, the posts will receive several hundred pounds alone w/o rain soaked snow so, this may be playing w/ disaster, but I'm willing to risk it, I wanted the look of solid wood, not a bunch of screwed  together 2x8's or 10"ers. ha. sorry for the crude drawing, and yeah, I got the 'keyed spline tenon' joint from the picture of a bed I saw.

[Justin Bailey]

I was hoping to make all my braces 38" but this will interfere w/ where they meet, I already cut all my 4x6x8' exactly in half, and now I regret it, should have cut them 44/52 or something. If I can get the beam up high enough on the post, maybe the front post's plate braces will not interfere. Thanks for reading. I may still have to buy some other longer 4x6's like 10'ers, and cut them in half just for the plate braces and I guess they could be longer anyway to help w/ the overkill span where I am attempting to use an underkill dimension lumber. I know you're only supposed to go up to 12' with 6x6, eh, thought what the heck. We'll see.

[Justin Bailey]

So my question, restated is 'Is there a general rule for how close to the top of a load bearing post that has a plate junction, an intersecting member w/ knee braces can be supported by a pegged spline tenon such as the one I described' (shown in the bed picture), I am guessing in relation to the shear strength of pressure treated southern yellow pine. I realize nor expect any answer from the former sufficiency of information given that anyone has a clear idea of what I am asking.

Like with a 6x6 member, a post that has a plate resting on it, with either a spline & dovetail assembly to join two plates on a single post or a simple wedged or vertical key half dovetail through tenon/mortise for a plate that continues past the post, as at the end of my simple structure, is there anyone with any profound insight regarding if I can have the bent's horizontal connecting member, within (given 5.5 x 5.5 actual) post size, 3,4,5,6,7,8 etc. inches from the plate resting on the post, given that my cumaru spline will be cantilevered across and driven through a mortise 3.5 x 1.5 inches, with a 1/2" over 5.5" wedge shape, with the cross beam resting dadoed 2-7/8" to fit onto the spline, and the spline protruding 7" into the end of that cross beam. Anyone? Here is another couple of pics of the tops of my posts I am working with.
   

[Jim_Rogers]

 

 

I was told that there should be at least 8" between the tie beam and the plate.

Does this answer your question?

Did you remove the bed picture?
You need to read and follow forum rules on posting pictures if you haven't read them already.

Jim Rogers

[Justin Bailey]

Thank you, I must have removed the bed picture from my gallery by mistake.  It sort of answers my question, I have a spline shape that has a head on it and may add some splitting resistance, so I have that to perhaps consider.

[Justin Bailey]

It is also a single sloped roof, not a large outward thrust there on the plate, Jim

[Justin Bailey]

Also, doesn't 8" refer to a given size of post?

[Justin Bailey]

I am only having trouble making bracing hold out to intersect between one-another you understand.

[Justin Bailey]

Does anyone have a forum rules link? Please bear with it, I am not sure what I have done wrong.

[Justin Bailey]

I wasn't sure how to upload pictures into a post, so I have accidentally deleted them from my gallery, but I have now restored all 10 pics to my gallery so far. Is that in accordance with the rules?

[witterbound]

I don't know of any rules you've broken.  I had trouble figuring out your question.  Once you clarified it, I just didn't have a clue what the answer was.  My hunch that's the reason for the lack of responses.

[WmFritz]

Does anyone have a forum rules link? Please bear with it, I am not sure what I have done wrong.

Justin, the Forum rules link is at the bottom of the page.

[Justin Bailey]

Thank you WmFritz.

[Justin Bailey]

Well it's kind of a odd application, single slope roof over a series of plates, sitting on bents that I am using in an unusual way to join 'tie beams' into the posts, and the post are 1' different in height, also the whole thing sits on a 2 degree slope lengthwise, lay-of-land, so all my plate braces are different on the one side of the posts vs. the other.  I just might have to get longer bracing, and some shorter, because now it seems, they're not going to all be able to be 'around' 38"...even if I theoretically have my tie beam right up to the bottom of my plate joints.

[Justin Bailey]

So by restoring my gallery, have I restored this thread, or are the picture links broken? Everything looks OK to me, but I don't know how everyone else sees it.

[Justin Bailey]

OK, so I have modified my use of H-e double hockey sticks word a few posts ago to 'heck', my apologies.

[PC-Urban-Sawyer]

so by restoring my gallery, have I restored this thread, or are the picture links broken? Everything looks OK to me, but I don't know how everyone else sees it.

Justin,

First of all, welcome to the Forestry Forum.

It does take a little getting used to the rules but the ones regarding pictures are to avoid the dreaded "X" which appears if a picture is referenced but can't be found...

You got almost all of them back. It looks to me like the only one missing is the first one on the first post on this thread. The info for the missing picture says it is https://forestryforum.com/gallery/albums/userpics/40041/WIN_20150607_221514.JPG

If you can't fix it any other way you can always edit the post and delete the reference.

Again, welcome to the Forestry Forum. And remember that "DanG" is both the official cuss word of the forum and the name of one of the our favorite members (I was trying to say he was a member for a long time but it kept coming out like I was trying to say he was old and @DanG I would NEVER say that!  :D :D ;D ;D )

Herb

[Justin Bailey]

I think now, I will just run my bents' tie beams at the same 1:12 angle that the roof will have, staying down at least 7" from the top of the post top/plate joint edge. This way, I can use relatively similar length bracing, or at least use my 48" lengths of wood of which I can make up to 44" long bracing on the obtuse angles, instead of having to buy longer and waste what I already have. Plus I can walk under the tie beam easily when handling firewood under the structure. It will be the strongest that way, too because I will have sufficient room on the post between perpendicular brace mortises. Sound good?

[Carpenter]

If I'm understanding your question.  You'll have a post and a crossbeam near the top as in the picture that Jim Rogers posted.  However instead of that crossbeam being mortice and tennoned with a peg it will be splined with the spline extending clear through the post.  The spline that you've pictured also has a head on it, so the spline won't be able to be pulled through the post unless the head breaks.  The spline will be pegged to the crossbeam instead of the post, roof spreading will put tension on those pegs, but the tension will be oriented with the long grain of the cross beam, where as in the example of the failure the tension was across the long grain.  As you are pulling clear through the post and changing some of the tension into compression on the back side of the post, I don't think it could possibly split the post.  I'm not an engineer, but in this scenario, I don't see how lowering the cross beams is going to take any pressure off of the system.  I do think that if you are going to put an outside wall on this frame, it will be a little challenging to work around the head of the spline. 

[Justin Bailey]

Thanks for the input, There won't be any walls in this structure, it's just a 'fancy' way of eliminating tarps over some firewood piles. The spline still will wedge into the post, and having it too close to the top of the post could be weak. I am however going to have a small housed inset letting the beam into the post an inch or so, sharing some of the load to the post itself, downward. My question, is as though having that tie joint close to the top of the post would not necessitate needing longer or unavailable with what I have, bracing, but it won't. Even if I had the beam that high, I would still need other lengths of bracing than I have, so my only strong solution is to have a sloping tie beam, and alike clearance for the adjoining plate braces on both ends of the bent. The posts again are 1 foot different heights, making plates that allow for resting the roof 4x6's at a slope. I don't really need more of a slope than that, I is only single pitch roof, and if it snows two feet and then starts to rain or something, I'll just get up on there with a shovel.  :laugh:

[Justin Bailey]

Here's a view of that tie beam at a 1:12 angle, and it is equidistant from both tops of the posts. Then I don't have to greatly vary my brace lengths, just do some trickier tenon shoulder angles on the bracing, I'm willing to do this.

 

[beenthere]

Justin
Only need to put one pic of each in your gallery. just sayin...

Can we help with the glitch that you are running into?

[Justin Bailey]

ha well, the 1st pic I saw had an 'x' so I re-uploaded it, now there is two?

[beenthere]

ha well, the 1st pic I saw had an 'x' so I re-uploaded it, now there is two?

I looked at what you loaded in your gallery... that is why I made the comment and asked the ?.  Something must be confusing you. ;)  We can help if you want.