E.H.,

Good point. I did my brace drawboring backasswards. I pre-made and pre-drilled all (140) of my braces, which then required very precise drilling of the mortise holes. Surely the way you describe it is the right way! Dooohhh!

-Thomas

Thomas,

well, I would get confused, too with that many braces and what to do first. Maybe you have had your friend "Bud" around one to many times?

Enrico

I have decided to fit the braces in the centre [center] of the post and peg all the way through as the car port will be open,so walls or cladding do not apply.
I am looking at 6"x 2.5" braces curved and 30"x 30" from the corner of the post if you can visulise it,the height up to the wall beam is 8ft,do you think this size of brace will look in scale.

Hello all:

Here is my 2 cents worth on this subject which I have taught many times over the years.

The placement of the braces to the outside of the historic timberframes did not happen without a reason, the main one being that the braces are in true alignment with the tenons that are on the posts which the braces are pushing against.

The tenons on the upper and lower ends of the vertical posts are placed roughly 2.25" from the exterior surface of the rough hewn timbers, therefore the pushing and racking of the framework due to wind pressure, etc. necessitated that the braces be placed in direct alignment ie: layout of the brace mortises would be 2.25" from the outside surfaces.

As the building wracked under wind pressures if the braces were placed in the centre as suggested above then the vertical posts would want to twist putting unusual strain on the frame and could cause a joint failure by snapping a tenon, or causing the framework to weaken.

The only place that braces are allowed to be placed in the centre of posts is where the through tenons are themselves in the centre of the posts.

A good example of this type of central layout could be in the centre bays of say a driveshed or barn where the connecting girts span from side to side. One that most people might relate to is the large anchor beams in the Old world Dutch Barns where The huge Tusk tenon passes through the vertical posts (centred), and the braces following suit are placed right in alignment in the centre of the post.

I might add here that some timberframers always offset the tenons no matter where the girts were in the building, while other centred the tenons where they could. Historically though all the outside timbers, posts, and plates and braces had their tenons and mortises offset to the outside, usually 2" from the exterior surface.

I personally have never found braces that were placed out of alignment with the corresponding layout of the tenons on their matching vertical posts.

I hope this helps to explain why braces are placed where they are in historic, or for that matter in modern frames by professional, or historical tradesmen, and I might say by engineering firms drawing up on site plans for construction purposes.
NH

Hello again;

After posting the above reply, there are a few more items that need to be addressed,

--P Smith--I have no idea what you are trying to put forward in your post when you mention three different measurements, could you clarify what it is that you mean by them in relation to layout--thanks in advance.

--MTF--Braces were never meant to be nailed to because as the building wracked due to wind pressures the nails would loosen, break or even loosen the siding, braces were always meant to work freely inside the board cladding

--Timbo--When working on hewn surfaced timbers, and doing tayout, a square certainly was used but was placed on chalk lines snapped on the rough surfaces, these lines represented a theoretical flat surface, and at no time did the hewer prepare a special smoother surface at any location as you mention in your post. Hewn surfaces are just that, rough, and in many instances twisted and very uneven, even from the hands of a very skilled axe man.

--Finally I have this observation about pinning wall braces. Over the years of observations, hardly any braces in historic frames were ever pinned this being for obvious reasons, as the building wracked due to wind forces, the little that pins passing through the tenon on a corner brace could due, would be practically nill. In the first place the tenon on the end of a braces does not extend into the cavity of a mortise any great distance and surely not far enough to prevent tear out under the tremendous strain generated by the wracking action of the building. Pinning might even crack the side of the vertical post where the braces's seating is located.

I realize though that in modern frames pinning the braces's ends is an accepted habit for what ever reason escapes me other than the aesethic look, and the lack of seatings for the ends of the braces as seen in modern construction methods
NH

What NH said ! Thats it exactly , for spanning (or central spanning beams) braces are strongest if the mort. for the brace is centered in the post. I've run it in a lot of old buildings, braces centered. Curved braces sound cool. I did curved braces on several projects. I use dovetails for bracing whenever I can. I would not recommend them for most softwood apl., I use larch almost exclusivly for frames.

The reality in the field from personal observation is that braces are almost always nailed with siding. Wheather that significantly adds much strength I don't know. And in our area of up-state NY many commericial type tf the braces where pegged. I would agree however that for the reasons you just outlined they probably wouldn't be worth the effort. But upon dismantling the pegs where apx. 90% intact. This frame was a coal and ice building that survived the great Carthage (NY) which leveled the city. It is a surprisingly well designed structure. In responce to hew to tighter tolerences I use chalk while hewing and choose my reference face and orient the log and hew this face to tighter tolerences. I don't know how any one could know how everyone hewed a log in the past. I then use a dry line during layout. I was not classicly trained as a framer (or typist)so many techniques I figured out or researched on my own.

Hi all,

why would it matter if the braces are being pegged or not? There is and should never be that much movement in any frame that the pegged braces would tear out. If they did then in all likelyhood the frame is not strong enough and the braces would fall right out if they were not pegged.
And eventhough siding is not meant to further stiffen the frame it usually does anyway once nail to the frame.

beerfreak,

wether the size will look to scale or not depends also on the size of all other timbers used. Say I am building it with 6x6 post I would use a 4x4 brace. Also the longer the brace the more it will stiffen the frame.
In trade school I remember being tought that a square cross section for posts and braces is always stronger than a rectangular one. And wise versa for beams and joists or rafters.
And yes, for your application centering the braces would look very nice.

Another thought: If the braces are not centered the forces will work unevenly on anything the brace will push against. It would eventually twist the post and beam. One can observe that on old frames a lot. The braces are to the exterior of the wall and so are the studs. The joists however are on the other side of the beam. The beam is always twisted and creates a hump in the floor above. If the beam would have been fully resting on the posts and studs below it would not have twisted like that.

NH
Good points. I believe that approach to TF worked well for the forefathers, but I’m not sure it would work today. If you are building non-code compliant buildings that would be fine, but unfortunately I do not believe that approach would support today’s building codes. For the most part, any code compliant frame will rely on a full shear wall (conventional framing/plywood), some shear resistance do to SSP, braces acting in both tension/compression or a combination of the above. I believe it would be difficult to design/engineer a stand alone TF that relies on braces acting in compression only. I know this point can be argued at length, but I do not believe it is feasible to design/build a standalone TF that does not include pegged braces or another lateral load carrying system. I know the TF’s the forefathers built are still standing, but it is getting increasing difficult to use that approach today.

I am not a true student of historic frames, but many/most that I have looked at included pegged braces. Actually, many of the ‘historic’ house frames that I have seen in southern NE I would classify as post and plank frames. These frames are lightly braced, certainly lightly braced by today’s standard, and relied on vertical oak siding boards for stiffness. There is no doubt that siding adds significant stiffness to a timber frame, how much is debatable. I try to take advantage of stiffness when available. If I’m nailing siding, or SSP’s, to the outside of the frame, I’m going to nail to the braces, as it does add stiffness. If I build a frame that was flexible enough such that the nails worked loss in the siding, I would stiffen it up.

Thanks,
Pete