Just wanna bounce this joinery off ya'll

[Brad_bb]

I'm planning to build a 3 bay frame 12'wide, 10', 12', 10' long bays.  This frame will go over top my lumber shelves so that I have a floor above my lumber so I can store more lumber or whatever and take advantage of the vertical space I have in my new shop.  I believe it's 14 feet to the top plate of the shop.  The lumber shelves are 8ft.

Anyhow, I've picked up some reclaimed material at good prices.  8x8 white oak, and four 14x8 Doug Fir timbers to use for the tie beams.  They are good because I can mortise them for the ends of the 2x floor joists.  Not sure If I should use 2x10's or 2x12's?

Anyway, here's what I sketched up this morning.  Trying to put the ties and plates the floor level, which is often hard to do in a TF.  Any thoughts appreciated.

 

[Jim_Rogers]

The location of the 8x8 tenons is not the best, as the timber could split under the load at the level of the bottom of the tenon, unless the 8x8 is also sitting on a shelf in the post. Also, those tenons are not long enough for the peg holes to have the correct distance to the end of the tenon to prevent blow out.

Jim Rogers

[GRadice]

There is Japanese timber frame joinery for this situation, if you are up for it. It involves either a long tenon or a spline to connect the 8x8s, overlapping the tenon from the 14x8. In this variation the spline also locks the crossing tenon, but there are multiple variations. Here is one sample:

 

 

 

[Brad_bb]

@Jim_Rogers I think what you are saying is not enough shear area at top and bottom of peg where the arrow is pointing?  As to the 8x8's coming into the 8x8 post at the same level, yes I figured some shoulder, but if the tenon is not long enough, what would you suggest?  I suppose they could move up a bit away from the 8x14 tie beam, but how to keep them at the same level on either side of the post?

Gradice suggestion seems like a lot more time and cutting than I'd like especially since I'd have to do it 4 times for the center bay.  While I appreciate the japanese style, this needs to be a bit more American traditional.  The horizontal 8x8's aren't perfect new material either, so I may need to contend with a little bow or crown and will need to orient them to work and may even need to snap line them as well.



 

[jaciausa]

The floor would need to support more than a normal load at times if filled with lumber? The posts would need more than a normal concrete floor with no footing. I am sure you have thought of this, but the footings, joinery and the floor joists should be calculated for the extra weight?

[Jim_Rogers]

Without understanding the load supports completely it's hard to advise you as to how to accomplish your goals. Why do you need the 8x8 to be at the same level as the 8x14? If this is lumber storage, which timbers are supporting the lumber? the 8x8 or the 8x14? I'm hoping the 8x14 as it is a stronger piece. if the 8x8s are just connecting bents to bents then then don't need to be at the same elevation. Lower them or raise them up so you can put a spline through the post into each 8x8 to connect them (no peg in the post). And not have this spline interfere with the tenon on the 8x14.
Three way and four way joints should be avoided as they weaken the post at that location.



 

[Brad_bb]

It's a 6 inch concrete floor with rebar.  

I wanted the floor level across because I'll lift stuff up with the forklift and set it up there from the side of the frame to put stuff up there.  I'll try not to put my heavy stuff up there, just as I load my pallet racking with heaviest on the floor then the first shelf etc.  

Here is a sketch of the frame.  I've got 8'2" under the tie beam for my lumber shelving that sits on the floor.  1. If I move the bent connectors below the tie, they will interfere with the lumber rack access. If I raise the tie to lower the bent connector, I lose some headroom above, which may not be the worst option, but might look funny with the connector 22" below the top of the tie.  2. Another option is the raise the connectors up higher, then I'd need to raise the joists higher and build up on top of the tie to support the top of the floor joists, to give me a floor level with the bent connectors.

How do I join the bent connectors to the post so they are at the same level, because I want the floor to extend over the top of those bent connectors?



 

[Jim_Rogers]

Ok, so you have supplied a nice drawing, but you never answered my questions. I'm again have to assume you want the 8x14 to support the lumber as tie beams. And the 8x8 are just connections from bent to bent not supporting any lumber load.
If this is true, then the spline joint for the 8x8 can be top splines going over the top of the tenon from the 8x14.





above is the joint with all timbers in place.
below is the timber in place but with see through turned on:



 

 
above is the timbers move out so you can see the shelfs cut into the post for the 8x14, and the 8x8x as well as the mortises for the pieces. I would peg the 8x8s to the spline with 1" pegs and not in the same grain line, that is staggered up and down. as mentioned no peg in the post into the spline. but at least two pegs into the post and through tenon on the 8x14 tie beam.

Jim Rogers

[Brad_bb]

Perfect Jim, thank you. A 2x6 spline with staggered pegs in the connectors is a much cleaner design.  Sorry, I think you missed in the previous posts where I call the 8x14 a tie beam, and in the original post I mentioned housing 2x floor joists into the 8x14's.  I was trying to be clear without cluttering with too much non essential info.  Having my last sketch first would have helped.  The 8x8 bent connectors won't really be taking much floor load other than when setting stuff up there before I move it back towards the other side or more out into the floor up there.  So maybe at most, 10% of something I set up there temporarily until I move it back.  For example if I set a pallet up there, no more than 8 inches of the pallet will sit over the the connector until I move it back.  I wanted the connectors flush with the floor so the decking can go over top of them to allow for getting the stuff up there with the forklift.

PS  Although I don't show it, I do plan to have braces.

[GRadice]

I think Jim's response is great. The Japanese version I suggested is conceptually similar and removes a little less wood from the post but probably not enough to matter and is much fussier to make. Splines are not as strong as a continuous tenon, but easier to assemble and usually plenty strong enough.

Good luck! Looking forward to the pix when it is done.

[jaciausa]

I believe this will make some nice storage. My thoughts, that you might place bunks of hardwood beams up there would overload the floor system. Will the diagonals be part of the design to help with the spliced 8x8 pocket or just for racking? I do not know much about timber framing and had never seen this detail. Is there a rule in figuring out the length of spine and its size? The depth of full 6 inches will only leave 2 inches under the spline.  Tim

[Jim_Rogers]

Will the diagonals be part of the design to help with the spliced 8x8 pocket or just for racking?  

Braces are for racking strength.

Is there a rule in figuring out the length of spine and its size?

The rule of thumb for figuring out the size and lengths that I used is shown in the drawing I posted above.

The depth of full 6 inches will only leave 2 inches under the spline.

That's why I suggested that the 8x8s sit on a shelf/housing shoulder in/on the post.

Jim Rogers

[GRadice]

Here is a rule of thumb for spline proportions in Japanese joinery, from a classic textbook. This illustration is of a solid tenon but you can easily imagine a spline instead. The author helpfully uses proportions rather than absolute numbers. In his scheme, the spline length beyond the post is twice the post width. The spline depth is 3/5 the beam depth. This one is fixed using tapered wedged tenons from above (or below) or a cleaner look but pegs from the sides are also used.



 

[Brad_bb]

@jaciausa Although I haven't done any specific calculations yet, I was thinking of using 2x10 or 2x12 floor joists on 12 in spacing with blocking.  I suspect this floor/frame would take quite a bit of load on each bay.  I will do some calculations.  I don't plan to load beams up there, though not out of the question to store some brace stock.  I might store lumber, or?  I have a Ford 515 sickle bar mower that I'm going to restore that I need to get out of the way.  So it may go up there for the time being. 

I'm also thinking about enclosing the lower bays and having access doors,  and insulating and dehumidifying to keep dry lumber from reabsorbing moisture.

a 2x6 spline in an 8x8 timber seems to be pretty common.  

[jaciausa]

Jim, Gradice
I have learnt a lot from these TF joints. The two techniques are very similar (tenon-spline). Using proportion and not nominal lumber sizes must be the principal I missed. I have to rebuild the tenons on a barn that I am disassembling. This thread has been very helpful learning about this connection. Instead of resizing lengthwise for missing tenons, use a spline-tenon? 
Brad, looks like that will be enough to hold even the loads I envisioned. Full 2" 12" hardwood joist on 12-inch centers? on a ¾ shelf mortise into the 8x14 timber. The solid bridging-blocking, will address the other thoughts I had on the forces that might happen from the side loading at the 8x8 beam. Getting items from front to back, rollers might help. Is there a 2inch floor in the plans? I am going to try to use some of the calculators to see what load might be possible. Tim

[Don P]

More for the bag of tricks, I think around pg 8. This is heavy timber mill type construction.
PDF Viewer (awc.org)

[Jim_Rogers]

Jim, Gradice
 Full 2" 12" hardwood joist on 12-inch centers? on a ¾ shelf mortise into the 8x14 timber. 

A 3/4" shelf into that timber may not be enough to support the weight of the load.
To determine the size of the shelf you'll have to figure the load on one joist. and then divide that load by 2 as each end supports half. Then you'll need to look at a chart for the load capacity of that type of wood perpendicular to the grain. 
example: 3/4" x 2" = 1.5 square inches. 
Brad has said that the distance between bents are going to be 10', 12', and 10' again. Let's use the longest 12'. unsupported span is 12' oc less width of timber 4" on each end, so 144-4-4=136"
12" spacing for each joist mean area is 12"x136" or 1632 sq inches= 11.33 sq feet.
Now the load. Let's say Brad puts up a 1000 lb lift of lumber. that lift is 4' wide as that is the limit of his forks. So, one joist is supporting 1/4 of 1000 lbs or 250 lbs again /2= 125 lbs.
Perpendicular to grain value on Douglas fir grade #2 is: 625 lbs per sq in. x 1.5 sq in = 937.5 lbs. 
937.5 is greater than 125 so my math says 3/4" is enough. (I didn't know if it was until I did this math).
The next step is to figure the area of the joist sitting in the pocket and its strength value. We know that he said a 2x10 or 2x12, but we don't know what type of wood he intends to use. That type of wood will/could determine the area of the shelf.
However, I feel that this (3/4") may not be the correct amount. We really don't know if this 8x14 is dry and will not shrink. If it does shrink, there is a risk of the joist falling out of that pocket.
Bridging or block will divide the load to more than one joist, which would help reduce the load on one joist.
A bunch of decking would also divide the load up but adds to the dead load on the joist.
If it was me, I'd cut the shelf into the 8x14 at least 1" or more.
Jim Rogers

[Don P]

Be careful when you go to non residential loads. Use some degree of impact mentality. Think about using 4x the load, you're gonna drop it, tip and hang a fork, etc.  Then look at your adjustment factors, you can double allowable Fb so it is the same as point loading in bending, but do not fool around with the connections, that's where you need the beef. They do get hammered if machinery is involved. I'm pretty good with machines, I still drop and bump, it isn't people walking around  .

[jaciausa]

Brad, instead of making the bents with the 4-way TF connections could you run the floor joists front to back of your plan, into the 8x14 D Fir mortised. Lay out the floor joists so you miss the posts that will carry the Douglas Fir 8x14.  Anchor the bottoms to concrete. The 8x8 ties if still needed for design or looks could be placed all the way to top at ceiling? You could hang some light stuff off of pegs.
 The joint would be a spline without the tie. I might have missed something back in the planning. If not hope this helps! Tim

[Brad_bb]

@jaciausa I'm not really sure I follow you.  I've read the post several times.  Are you saying to eliminate the 8x8 bent connectors and have a 2x12 at the outter edge of the bay in place of the connector?  If that is what you are suggesting, I'd prefer a timberframed 8x8. 

I think I'll have white oak for the ones in the 12' bay.  I might have white oak for all, not sure yet.  I have 7 circle sawn timbers sitting there and I know two are not WO, but need to examine them to see what they are.  These came out of a barn but don't have any joinery in them.  They were a relatively more modern addition to an old barn. Got them from my barn wood dealer who gave me a good deal.  He gets the good money for hewn timbers. ;D  I don't have the posts yet.  I may have to order new or if I can find good reclaimed barn Oak, that may suffice.  Trying to do this cost effectively.  I found the DF ties for $100 each.  The guy told me they were under the floor of a house that burnt down.  One timber is charred on the end, that part will get cut off anyway.  They are good.  I'll run over them with a Makita wheel brush and make them look good.

My posts will be secured to the concrete floor with either knife plates or timberlinx.  With the timberlinx, a 1/4" plexiglass plate is used on the bottom of the post to prevent contact with the concrete to prevent moisture wicking.

[Hilltop366]

I think he is saying that it could be an advantage to put the floor joist going the other direction (front to back) it would: (1) cut the load (sqft) on the beam that the floor joist are connected to by roughly ½. (2) the floor joist are connected to the front and rear beams so you would no longer need the front to rear connecting at the middle posts or can raise or lower them. (3) reduce floor height connections at post to two beams which would strengthen post at connection area and simplify joinery.

Or I could be totally mistaken.

[Brad_bb]

I apologize hilltop366 as I'm having a difficult time fully understanding "so you would no longer need the front to rear connecting at the middle posts"
A sketch would really help, they're worth 1000 words I hear .

Maybe I can clarify by stating a few things:
I have the floor joists running from tie beam to tie beam because they are 8x14 and can easily be mortised to hold the floor joists without using any metal brackets.  (Incidentally, thank you Jim for that calculation exercise.  My inclination was to use a 1" deep mortise pocket for the joists.)  These beams are tall and have the carrying capacity for the floor system as Jim has showed.  Some of my design parameters are that I want 12' 2" between the center bay posts for my shelving below, which is 12'wide.  that means that the joists will need to be 12' 4".  My immediate inclination is 2x12 framing lumber joist or possibly I-joists.  I'm leaning towards the framing lumber though.   

The height of my shelving is 8', but I would like to be able to stack some plywood on top and have some clearance to the floor joists.  So I'm thinking that I'd like 9' to the bottom of the floor joists. That would put the top of the tie beams at 10ft.   

I want the bent connectors(8x8 WO) to be flush with the top of the tie beams so that it is one continuous floor- I can lay a plywood sub-floor over one planer surface.  The plywood floor will have to be at least two layers if not three.  I was thinking I may need to use a pallet jack up there to move stuff to the back.  I'm sure I'll also have to hand move some stuff.

Lastly, just so you understand my thinking.  I'm looking at having the posts extend up 4-6 feet above the floor.  The purpose is two fold.  It makes it easy to attach a railing, one that I can remove easily in the front when lifting stuff up there with the forklift.  Secondly, if this frame were to ever be removed- not needed, it would be easy to add a roof system for the second floor.  It could become a cabin or addition to another frame.  Probably after I'm dead.  There's a plan for a similar style frame on timber frame headquarters 14x36 with attached shed roof.  I figured I'd build mine so it could end up similar.


 
Here is my lumber shelving unit.  They are 3 sets of racking put together.  They were racking I had in my mom's storage lockers organizing her stuff, but now she's cleaned them out and I'm repurposing the racking. Half inch plywood will line each shelf so lumber fill slide in and out properly and keep the weight spread out. The unit is 12ft wide, 8' deep and 8' high.  I'll end up with about 3-4 ft in front of the shelf unit before the outside of the timber frame.


 

 

 

In the first pic, you can see the stack with the Doug fir timbers on top.  I've de-nailed them, just need to clean them up now.

[Hilltop366]

I apologize hilltop366 as I'm having a difficult time fully understanding "so you would no longer need the front to rear connecting at the middle posts"

I think what he was trying to say is the floor joist would be tying the front to the rear instead of the 8x14 which would either eliminate the need for them at that location or allow you to raise or lower the tie (it could be smaller because it is no longer holding the floor up)  to avoid the need for three connections at the same place in the post. The 8x14 could be along the front and rear if you had enough of them and would significantly increase the load capacity of the floor system.

[Don P]

These beams are tall and have the carrying capacity for the floor system as Jim has showed

Hold on .
Unless I'm missing something there has been no check of those tie beams before or after mortising. Deduct the depth of the joist mortises from the tie beam's section when doing those calcs unless using tusk tenons on the joists preserving the upper edge of the tie (Brungraber). No less than 1.5" mortise depth leaves at best a 5x14. Metal hangers or running on top of girders, in whichever direction, avoids this.

There is an oak frame I was involved with. Drop in dovetail joists, 1" tenons. As the dovetails have shrunk and then withdrawn in subsequent storms. I can almost slip my thumb in the gaps in places. The joists are hanging more on the sheathing screws and flooring nails in withdrawal than anything.

We just got another input. That pallet jack is a wandering point load. It's relief popoff setting is the magnitude of the point load. When it drops, that is an impact load.

[Brad_bb]

@Hilltop366 A couple of problems I see with that.  If you only change the directions of the Joyce now you're trying to put a 2 x 12 into an 8 x 8. A reduced 8 x 8 it's not going to handle the load nearly as well as an 8 x 14. Secondly have the issue of how you're going to attach the joist to the 8 x 8. If you have to add metal that's a negative. The other issue is if you're relying on this to hold your frame together instead of the ties, then you'll have spreading force on the ends of your joists, and joists are not designed to resist spreading force like that. I cannot put the 8 x 14's as connectors because I only have four of them.

Don. We're not talking about 3000 pound point loads here. Off the top of my head maybe the maximum more lifting could be 1000 pounds at a time.  I'm not really sure what I'm going to put up there. But as I said wait early on, I'm definitely going to try not to put my heaviest stuff up there. The sicklebar mower is on a pallet for example and it's probably not more than 400 pounds.  I might put some shelving up there to put my Barnwood in barn with scraps so they can be somewhat organized. That would not be very heavy, but I might lift up a pallet with 400 pounds on it to restack on shelves. There would be enough boards or subfloor under the shelves to spread the load out.  Right now I have a bunch of extra building materials like lighting fixtures, stainless steel sinks etc. maybe I'll use one bay for that stuff.   You have to be intelligent and cognizant of how you load it.

[Don P]

Brad, that is certainly your call, I would not use less than residential floor loading.
Then,

Unless I'm missing something there has been no check of those tie beams before or after mortising.

[Don P]

Putting some numbers to it... rational design and all. You've pondered the end connections. Let's see what that mortised tie can do in bending.

I found the tie beam span in the first post and enough info in the sketches to i think check that as a residential load, yes, a good sketch is worth a thousand words.

It looks like the tie is spanning roughly 11'.
Half the 10' joist span on the right of the tie, 5', and half of the 12' span on the left of the tie, 6', is supported by the tie. Tributary area is then 11' x 11' x (40psf LL + 10psf DL). 6050 lbs total load, 1210 lbs DL

Using this calc;
Design for Bending (forestryforum.com)

The minimum bearing for the joists by code is 1.5" so checking a #2 DougFir B&S 5" x 14" ... and it looks like you can put in code minimum bearing for the joists.

If they were notched with a "fire cut", essentially creating a tusk tenon, you would be approaching an 8x14 for design strength instead of the 5x14 that drop in joists create. Whether that can be assembled in there is another matter to consider but a little creative thinking.

It passes residential with drop ins. It can be much stronger with a minimum more work. I would do 2x10's even if closer spaced to leave more wood under the joist pocket. They are another check and you can adjust spacing, someone mentioned 12" which would help with subfloor span and wheel loads.

What do we know about a point load Vs a uniformly distributed load... A point load at midspan produces twice the bending moment compared to a uniformly spread out load. In this case, you're good for 2 tons of uniformly distributed treasure or about a ton rolling around if there is nothing else loading that area.

[Brad_bb]

@Don P What is a "Fire cut"?  Do you have a pic or sketch?  I know what a tusk tenon is but don't know what a fire cut is on a 2x10 or 2x12?  If it is some kind of tusk tenon, assembly could be tricky as you mentioned.

Thanks for the input.

[Don P]

Go back a page to that heavy timber link from awc, it is another industrial framing joint. Pg 10 fig D2 (yup, I got 20 tabs open  :D)
You are not using it for fire but because that or a tusk tenon preserves the top strap of the tie beam.

If you decide to go that way, regroup and decide if you want to design the floor for higher possible load. If you use drop in joists you're limited to around residential loading... and there wouldn't be much reason to use joists heavier than that. Check, but I suspect 2x8's would work, which matches the end 8x8's. (depending on species, grade, yada)

If you go with joinery that preserves a stronger tie, then, I would make the joists capacity match the ties strength. Couple of ways to go here.

Edit:
I hit google for a pic, and got one  :D
Firecut joists in masonry in Timber Framing/Log construction (forestryforum.com)

[jaciausa]

I should have looked more closely at your materials you have acquired. What I have suggested would not work unless you had 2 more of the 8x14 DFs to match! I was trying to eliminate the 3-way connection to the 8x8 posts. The 8x8's I suggested at the top of the 3 bents at the ceiling height would tie the tops of your bent posts. If you smacked the bottoms, or the top of the bent from front or back with equipment, it would eliminate the lever that is not tied together at top. I currently am dismantling a barn that has many problems. One of them is the removal of a tie at the top of bent (actually part of the original bent) to use a hay trolley without interference, (kind of like yours will be without a tie at ceiling). The only tie in barn is 9ft up on the 20ft tall post. It now is just an H bent, partial bent? It has survived many years, since 1910.  I plan on putting it back up. I will have to saw a lot of replacement timbers, braces to tie it back together. I will be adding a floor just like your storage area.
Like you, I want to be able to make it look nice by contrasting the different parts. Having them all dried down the same without a vacuum kiln would be impossible timewise. Working with the green and the dry timbers will be a challenge.
 Saw 3- 8x14 WO for front, use 3- 8x14 DF rear, put 1 DF away. Saw and dry full 2x12 WO joists 12" centers, 2"x6 t x g flooring hardwood pegged to joists. Use 8"x8" ties at ceiling as needed. 
 
 

[Brad_bb]

Ok, I'm warming to the idea of the firecut ends.  How about 2" depth into the DF beam giving a 1.5"x2"=3 square inch bearing area on each end?  I suppose those angled pockets could be cut with a router jig.  With those pockets in the Doug Fir beam, would you reduce the beam size at all for calculation purposes?  

That is my first time looking at the Design for bending calculator.  Did you make that Don?  So I figure the Doug fir beam will be shouldered into the post (as seen in the original post sketch) for a 1"deep bearing surface so roughly 8 square inches of bearing on each end.  So when I look at the calculator, it looks like to get an idea of the load it can handle, I can increase the loading as long as the bearing area is not exceeded and everything passes?  Am I looking at that correctly?

jaciausa, as I plan to extend the posts up 4-6 feet above the floor, I will put tenons on top for a plate on each side.  I may not put the plate on right away, depends on when I can get the material and time to cut the plates and do scarfs.  The frame would then be ready for a roof system if it were ever repurposed someday.

Don, I saw you use the abbreviation "BO".  I wasn't sure what that was, then I saw you use it in another recent post.  I'm thinking it means builder/owner?

[Don P]

If you can avoid damaging a 2" strap of wood along each edge I would not reduce the beam dimensions in the calc. Similar to an I beam, the middle web of the beam is mainly holding the edges as far apart as possible and taking care of the horizontal shear. In other words, make the diagonal exit the beam 2" below the top edge. I don't think a router is going to do it, I suspect this is a sharp chisel job, maybe a little drilling, alas.

The lower edge does become an issue as the bottom strap gets thinner, as the notch lowers from the neutral axis, and as the load increases. I can't give you anything hard and fast but the stress begins to shift from shear under the joists to tension perpendicular to grain across the entire bottom strap. That is why I was leaning away from 2x12's, to leave more meat under the joist and push the bottom of the mortise up towards the neutral axis.

As folks have.... guessed... at various member dimensions, I guess what I'm hoping to show is that the parts should be sized together, no one part needs to be, nor should be, grossly over or undersized. Parts should work together in concert.

 That calc is one of a series. The math equations are fairly simple, APA's DCA6 or any engineering text. The real trick is knowing which engineering equation models the situation at hand. That was one for heavy timbers 5x5 and larger. The joists would use one for dimensional lumber here;
Dimensional Lumber Calc
"Lumber" and "heavy timber", of the same species and grade, will have different design values, do not mix up the calcs.

This is the overall list of beam and column calcs (the red toolbox, bottom of the left column)
ToolBox (forestryforum.com)

It sounds like you are understanding correctly, see what the beam can handle in bending, then check the allowable compression perp to grain against the design compression on the bearing area at the posts. Following that to ground, there are column capacity calcs in the list as well ut this sounds easier than that. An 8' tall 8x8 post does not fail by buckling, it dies by crushing. If the beam passed compression perp, the short post passes.

BO is Builiding Official, head inspector. You'll also see AHJ sometimes in those conversations, Authority Having Jurisdiction, generally the BO but can be the Fire Chief, the County Admin, or some other bear.

[jaciausa]

Brad, with anything over 8" for the floor joists they will be below the8x8 tie beam you have, as viewed from sides. To me that would not look the best. Giving more meat on the DF beam under the joists is something others have said is needed. Maybe a 4x8 joist (different centers) or 2x8's that would calc out would be best?
You do not have the joist materials, so you might be able to get some dry timbers from a floor from your barnwood person. Some of the barns have logs for joists. I have seen many of these burnt or sold for very little. They look ugly to most, but I planned the top of a hand hewn- on top only, white oak log joist the other day and it was perfect. From the rings and size, they must be the tops out of the 12x12 Hand hewn white oak timbers in barn. Hope this helps. Tim