Brace Layout Question and Answers

[Jim_Rogers]

Laying out a Brace Corner

Part one.

The other day a timber framer sent me an email asking me:

"Hey Jim, Quick question...do you know of a publication that provides detailed layout
and cutting procedures for the wind brace joints? This is the only one that
is making me a little nervous! They have to be right."

My first response was to ask him what he meant by wind brace.

He said: "Other terms I guess would be "corner brace" or "knee brace". A 45 degree
brace from posts to tie beams, to plates, and to perlin plates etc."

Here is my advice. The most important thing to remember is that brace layout is done correctly.

The brace timber itself is the hypotenuse of the right triangle. And this right triangle is an equal lateral and equal angular triangle. That is that both "legs" of the triangle are the same length, and the two angles are both 45°. (I'm sure you knew that).

The key to laying out a pair of brace pockets on two different timbers so that the brace fits correctly is the "starting point" or the corner that makes the right triangle.
This point is where all the brace measurements will start from. That is, all of the braces that go from the same size post to the same size tie, in each bent of a frame.  And in every bent of that frame. So that they work and look correct from opposite side of bent to opposite side of the same bent. And that all braces will be the same size (if that is your intention).





Sorry for the low quality of this drawing. But it's to show you how a brace corner should look. And if you don't have a drawing showing you the brace layout, then you should make one and use it each time you need to figure out where the starting point is. Then you can refer to the drawing and it will help you to understand the layout. This drawing shows a 36" brace layout.

Now how do we figure out where this "starting point" is?

We have some answers already. First what is the frame's convention, in regard to sizing of joints?
If the joints are framed to the next 1/2" smaller timber then the brace pocket has to be housed back to the next smaller 1/2" from the full dimension of the timber. At both ends.
So if you were to draw a line on your timber, with a pencil at a distance ½" under the full dimension, of your timber, from the layout edge towards the corner on either timber the post or the tie, these lines would be the leg of the right triangle. Now where these lines meet when the two timbers are connected is the starting point.
In the drawing below the full dimension of the post is 8". The brace layout line would be drawn at 7 ½" from the layout edge of the post. The tie beam is 10" tall, and the layout edge is the top edge. The brace layout line would be 9 ½" down from the top of the tie beam. Such as this:





And then you layout your brace pocket location, in this case 36", like this:





Now this is all great and well, when the pieces are all assembled but we have to layout these brace pockets on the tie beam and the post when they aren't all assembled.
So let's look at these apart.


Next posting will show more........


Jim Rogers

[Jim_Rogers]

Laying out a Brace Corner
Part two.

The next thing we have to look at is where the starting point is when the pieces are apart:





If you can refer to the drawing and it will help you understand where the starting point is.

The drawing will tell you where the brace pockets are. Note that all brace pockets are laid out from the over all dimension; in this case it is 36", back towards the starting point. This is the most common mistake that beginners make is to layout the brace pocket on the wrong side of the 36" point.





(Caption in photo reads: Because the housing is a 1/2" on the braces and the housing is 1" on the tie to post, the starting point is 1/2" off the housing on the post, and 1/2" off the shoulder on the tie. If your tie is housed down 1/2" at the tenon that joins with the post then the starting point is on this line.)

Also you have to understand how to layout the 45° angle cuts on the brace to make them the correct length to fit into the corner and not be two long or two short.

If you make the brace too long, this error will be greatly increased because of the lengths of the "legs" of the triangle. And other parts of the frame will be affected.

If you make the brace too short, this error will affect the braces' ability to do its job which is to stop the frame from racking when wind load is applied to the structure.

More next posting.......

Jim Rogers

[Jim_Rogers]

Laying out a Brace Corner
Part three.

You have to understand how to layout the 45° angle cuts on the brace to make them the correct length to fit into the corner and not be two long or two short.

The next thing you have to figure is the brace length, in inches and sixteenths so we can use our tape measure and or rulers to lay it out. So we use the formula a²+b²=c². So what that means in this case is (36"x36") + (36"x36") =? Or (1296) + (1296) = 2592. In order to get the brace length we now need to know what is the square root of 2592? The answer is 50.9116 in decimal inches. Now that we have that answer, we need to convert decimal inches into inches and standard sixteenths. How do we do that? Well, first of all would just drop the 50" for now and let's look at .9116 and let's convert that to 16ths so you and use your tape measure or ruler which is has inches divided into 16ths. You do that by multiplying that number (.9116) by 16 (and don't forget the point), and you'll get 14.5856. This is 14.5856 16ths. Next round off or up whatever it needs 14.586, then 14.59, then 14.6, then 15. So that's 15/16ths of an inch (it's better to have your braces a little long and trim later than to have them short and have to shim them.)

Add back the 50 inches we dropped for the moment, and we now know that the brace length is 50 15/16". This is the distance from point to point on the hypotenuse of the triangle. But the triangle hypotenuse line is not on the face of the brace, as the triangle is set into the tie and the post by the housing set back.

So we have to set back this line on the face of the brace in order to locate our two end points of the hypotenuse. If we don't set this line back then the surface of the brace won't be flush with the surface of the post or tie.

This set back line is drawn 3/8" off the layout face of the brace, which is the outside of the brace, with a pencil, on each end of our brace stock:




Then you select a point at one end of your brace stock, allowing enough room for the tenon, and measure from that point on the 3/8" line 50 15/16" and create another point. And mark these two points with a pencil on this 3/8" line. These points are the ends of the hypotenuse. The two 45° lines that create the shoulder line and the tenon bearing end line pass threw these two end points. We usually layout one end first and then the other. That way you can see which side of the brace stock each line has to be on in order for both ends to be mirror images of each other.

You start by making a 45° line threw the point for the bearing end of the brace, number one shown below.





Then you draw a 45° line threw the same point making line number two (shown above). Each time you do this the reference face is the outside of the brace, which is the side the 3/8" line is on, not the inside of the brace. That means you hold your combination square or your speed square against this layout face.

Then you measure up line one the length of the tenon (in the example above it is a four inch by six inch brace with a two inch thick tenon, offset two inch from the layout face and the tenon is three inches long).

And make a line parallel to line two for the end of tenon line. Line number two is really your shoulder line; this line is only cut the depth of the shoulder or the depth of the offset which is two inch deep in this case.

Now that you have these three lines drawn on your rough stock you need to draw more lines on both ends of line one and line three down each side of the brace stock using a speed square or a combination square from this layout face. Line two will be drawn down later, not now.

You can then connect the lines dropped down the sides of your stock that is the end of line one and three on the back side of the brace.

Next, you need to make some cuts to expose the end of the tenons and so you can make more layout lines.

The procedure for cutting a brace is to cut line three first. This will remove a lot of waste wood and this line isn't that important as it's the end of the tenon and maybe cut back later, depending on your mortise pocket.

Once you have cut line number three, you cut line number one. This line is called the bearing surface or bearing end as this is the end of the tenon that will be in compression when the building rocks in the wind. This line has to be very accurately cut. No mistakes not under, not at the wrong angle. It can be cut away from the line but then you'll have to "pare" to the line and make it correct. We score all lines with a knife first before we cut with a saw, to prevent the wood from tearing out and help make the line straight and true.

Once line number one has been cut you'll have the end of the brace stock to draw more lines on. Next you draw or drop line two down the thickness of the offset which is two inches on each end. And then connect the ends of these two dropped lines around the end of the tenon. This will show you the amount of wood that has to be removed to make the tenon. As we do layout work like this we mark all waste wood with "X"s so that we know what parts are waste, and what parts isn't waste. We also mark on the end of the tenon the word "tenon" so we know that this part is not suppose to be cut off.

After you have marked the dropped lines of each end of line two and have connected them and marked the waste wood and scored line two all the way around; you cut line two, with a saw. After you have cut line two, the shoulder cut, and you don't cut it any deeper than the offset two inch, we usually chisel off the waste wood.

Now some people here, at my workshops, have just taken a saw and cut the waste wood off, but more times than not, they have made a mistake and cut the tenon line wrong and therefore have made the offset wrong, usually too thin. So we chisel it off.

Start by clamping the brace onto a sawhorse and using a 1 1/2" or two inch chisel and a mallet, chop off some of the waste wood. Now when I say chop some off, what I mean is you take off just a little maybe 1/4 to 1/2" from the top corner down, then move over and take some off the corner on other side of that tenon. Take the waste wood off the side of the tenon working your way down to the tenon face slowly and evenly so that you don't make your tenon face too deep or too shallow. You can hang your framing square on the shoulder line to gauge whether or not you've got the tenon trimmed down enough.

These procedures need a series of step by step photographs and maybe next workshop I can take some to show you.

Once you have the tenon face trimmed down to two inches off the layout face you can flip it over and shave off the back side with a hand plane until the tenon is two inches thick, which is if your brace stock started at 4 1/8" thick. That's what we do and this makes the back side flat and smooth.

If your brace stock is only four inches thick be careful as you cut the tenon face not to make the tenon too thin. It's better to start with thicker stock then thin stock.

If your brace pockets are centered on the post it's done a little bit different.

Once you have one end done you do the other end the same way but be careful not to cut your shoulder line to short or your brace will be too short for your housing.

That 3/8" offset line on the braces only works if the housing is 1/2" if the brace housing is one inch then the offset line is 1/2".

Also, even though line number one doesn't look like it lines up with the end of the tenon; it does that just because of the angle of the camera taking the picture in the rendering program.
Here is another isometric view:




When you establish frame conventions, such as two inch off layout face, and two inch thick tenons, this is also a way to remember what order you cut things. First you establish the tenon face two inch off the layout face and then you make the tenon two inch thick. That way you shave off the thick part of the tenon from the back side making it thinner, not shave off the layout side moving the brace closer to the outside.

It's important that once you've established that two inch offset you don't shave any more of that side, as it will move the whole piece towards that side, and that's something you don't want to do.

Read it over and ask questions.

Jim Rogers

[Kirk_Allen]

Jim,
Thanks for all the info.  Sorry its taken so long to thank you but I guess I have spent to much time on other parts of the FF.

I bought my mill for the purpose of building a Timber Frame home in Hains Alaska.  I am now at a point where I need to lay out some plans and start cutting some beams.

Im sure I will have many questions as I am slow to learn from reading.  I do much better hands on.

Thanks for sharing you knowledge.

Kirk

[beetle]

Jim..Thank you!

My braces and pockets came out right on the first try.
 A couple questions:

When you have brace pockets on opposing sides of a post, do you cut a through mortise or two blind ones leaving a little stock in the center? My posts a 8"x 8" with two 3.5" deep pockets which includes the 1/2" housing depths.

When pinning a brace with a 2" offset x 2" tenon, do you pin through the entire post ?

Again, thanks. I could not have done it without the info you provided.

Jeff

[Jim_Rogers]

Jeff/Beetle:

When you layout a brace tenon you usually lay it out for a full inch measure and then after all is done you trim it back one eight of an inch.

In the frame that we are about to raise here at my sawmill yard, we have 3" tenons on the braces cut back to 2 7/8". And mortises that are cut to 3" deep from the should line, hopefully not cut much deeper but they can be up to 3 1/4" deep from the shoulder. This gap is to insure that the tenon doesn't bottom out in the mortise when everything dries.

The method the brace mortise is cut will determine if the brace pocket will be a threw mortise or a blind mortise. If you are using a chain mortiser, then most likely it will be a through mortise. If you're using a boring machine or power drill, chances are then they mortise will be just the depth it needs to be.

Personally I feel if you can leave the wood in between the mortises, I would. Every bit will help to make the post stronger.

All peg holes are always drilled from the layout face. All pegs are driven from the layout face.

If there isn't a timber blocking the back side of the hole location on the back side of the post/timber, then all holes are through holes bored through from the layout face.

If the bit hits some internal defect, like a knot, and wanders off line after passing through the mortise then it really doesn't matter. But from the layout face threw the mortise should be right on the mark.

A lot of this will depend on the type of pegs you're using.
If you are buying turned pegs or pegs that look like dowels then you could do a blind peg hole. But if you are shaping your own pegs using a shaving horse and a draw knife then you should allow enough room for the taper point to pass beyond the back side of the mortise at least 2" or more. This will allow more holding wood to hold the peg and tenon in the mortise.

On our frame here we are using 10" long pegs to go through 6x6 timbers, with through holes at every mortise.
It is very easy to push a peg out of a through hole, then to pull one from a blind hole, in case you need to take your frame down.

When we raise our frame here, in a few weeks, we will not be driving the pegs all the way in, because this frame is still "for sale" and will be disassembled and moved to the customer's site, once sold. We will drive the pegs in enough to hold the frame together and for it to be safe.

Thanks for the question, it was a good question and that's why I posted it with the answer.

I'm looking forward to seeing your finished frame pictures....

Jim Rogers

[beetle]

Thank you again. On the posts that I have completed I bored blind mortises and left the approx. 1" of stock between them, ( I was not sure and felt I could always take it out later but I can't put it back). I plan on using hand carved pegs, going to wait and bore my peg holes when it is time to assemble so they do not egg shape on me.

So far I have connected to no electricity or poured any gasoline, different from what I have done in the past and I aint covered with dust and smelling fumes...kinda nice.

Have fun.

[beetle]

So far I have cut 24  brace pockets on my posts. I am using the 2 / 2 method off the layout face with 1/2" housings.

A couple of my housings I have accidentally got a little deep, about a 1/16" to a 1/8" at the most. What problems is this going to cause at time of assembly and raising ? If it will cause trouble, any suggestions on how to correct them?

[Jim_Rogers]

Jeff/Beetle:

I had planned on doing a story about how to cut a brace pocket as it was missing from the above story.

I'm sorry I haven't gotten to that yet.

As to your questions about the depth of your pockets. If the actual pocket where the tenon goes is too deep that isn't a problem and you shouldn't have to worry about that. As long as the bearing end of the pocket is cut correctly, as well as the bearing end of the tenon on the brace. These location have to be exact.

But if you're referring to the housing area where the shoulder of the brace rests on, it's important that this be correct as a good part of the bearing is at this shoulder as well as at the bearing end.

You'll need to cut a shim and put it in/on the housing to bring it back up to the correct place.

If you don't it won't work as well as it could and it won't look very good.


The procedure for cutting a brace pocket is to lay it out, knife the lines around the pocket and then cut out the pocket. Using a boring machine or a drill you hog out the waste wood and then "pare" to the knife line to the size of the pocket opening.
After all this is done to the correct depth. You then cut the housing at the edge of the pocket, where the shoulder of the brace will sit. Basically housing is cut last.
Once the housing is cut you then locate your peg hole.

I'll do a step by step photo shoot of this sometime and will write up a story about it.

Good luck with your project.

Jim Rogers

[beetle]

Thanks Jim,

Yep it is the 1/2" housing depth that I am referring to. On a couple of them the chisel caught the grain and I am somewhere around 9/16 deep. Going to have to be a little more carefull.

I have been cutting just as you described above...Mark, score, bore, and chisel the mortise, then I cut down the housing depth 1/2" line with a crosscut saw then chisel to the paralel line. I just caught the grain on a couple and ended up a little deeper than 1/2". Guess I will have to shim.

[Jim_Rogers]

Jeff/Beetle:

You need to score the housing line on the side of the timber, the side the peg hole is laid out on. This will help you to not over cut it.

When I say we score "all" lines that means all the lines we will cut to, even housing lines. And housing lines can travel around corners onto other faces, sometimes.

We even score lines that will be cut off later, so that we can use the scored line first.

Keep an eye on your lines.

Jim Rogers

[beetle]

Jim,

That statement got me thinking about some good old memories.... my Dad teaching me how to drive that old 69 Ford truck with a three on the column. He kept telling me " keep a eye on the line son "

Thanks.....

[beetle]

Jim,

If I identify the ones that I have overcut, can I correct them by increasing the 3/8" offset line slightly and fitting each brace to the those housings? If I do not screw anymore up, I should only have two or three that would need custom fitting, therefore, eliminating the need to shim.

[Jim_Rogers]

Jeff/Beetle:
Yes, but the new special one will have to be properly labeled (some place where it won't show), that these are special ones to be used in only that special location.
It should work if you increase the 3/8" line to the actual surface, but I've never tried it so, when I say it should work that's in theory.
Let us know how you make out.
Jim Rogers

[beetle]

Hello everyone, hope you all had good holidays.

Since I cannot get much done outside this time of year, I have been cutting all my braces and girts inside my shop.

I estimate that I will raise my barn around July/August 2005, if I drill the peg holes in the braces and Girts now are they going to "egg shape " on me while stored this lenght of time ? 6-7 months. All of the other timbers I have cut I have not drilled the holes since some of them will have been cut for a year.


Still chipping in Ohio

[Jim_Rogers]

Drilling holes now, may not be the best method.
First of all the holes could distort and change shape and end up egg shaped, as you say.
But also, you holes may not be in the right place, on the tenon.
I tried to say and show before that you should bore your holes at the time of your full scale fit up. If you bore the mortise holes dead on the spot or mark then they will be ok. Then if you're using a draw bore you should offset your holes on the tenon, as needed to create the draw bore. This is done by placing the tenon in the mortise and running the bit down the mortise peg hole and prick the tenon to indicate the exact hole location center, then offset from there.
If during your full scale fit up you see that your frame is not coming together right, as dimensions don't measure out right then you may need to shave a shoulder or two to adjust the fit. This could move the hole location some and therefore through out the draw bore or correct hole location.
I'd wait and bore all holes later.
Jim Rogers

[beetle]

Good point about trimming and or adjusting may throw the tenon hole out of tolerance. I will wait and drill upon fit up.

Thank you for the good advise.

Jeff

[Jim_Rogers]

Read the new posts about procedures.......

And keep asking questions.......

[Tony_T]

Hi Jim,

Was just soaking in your guidance on laying out/cutting braces by square rule, thanks!

Stubborn me have been teaching myself layout by scribe rule method and think I've got it figured out how to layout braces using compass, chaulkline, plumbbob, etc. 

I can get diagonal lenghts by laying out a reference triangle based on the depth of the "true" brace using the compass.  Setting the compass to the reference triangle you can walk out turns for diagonal lenghts and for positioning the pockets to layout the mortises on the beams; no "math" involved (e.g. A2 + B2 = C2). Unlike using the sqaure rule above I assume the brace is oversize and end up with a slightly oversize brace except on the ends that have been trued for the tennon and to fit the pocket.  That is the brace fits well but may not be flush with the beam where it meets the pocket.

Took me two days on paper to figure how to get diagonal lenghts without a ruler and calculations., that is only using the compass for measurements.  Do you know of any reference books for layout by scribe rule?  Will start playing with rafter layouts next........

[Jim_Rogers]

Tony_T:
I don't know of any books that talk about laying out for scribe rule.
I thought you'd lay one timber over the other and transfer locations by using a plumb bob line.
This would tell you where the mortise should be and also the tenon.
I don't personally have any experience in scribing but the magazine "Timber Framing" just had an article about it.
If you're not a member of the guild you could buy one copy of this magazine to read that article.
I can let you know the publication number if you need/want it.
Jim Rogers

[hayton1960]

I read tfg magazine 34, 35 and 36, Marc Guilhemjouans 3 part "introduction to French scribe", which is very useful, only it just sort of ends abruptly and leaves you in mid air not knowing where to go next just when it starts to get real interesting. PS does anybody know what is going on with his new site; the forum is like a ghost town, as far as I can tell I'm the only person who posted anything (except the site manager)! Do I have a fault with my computer?
Cheers Jonathan

[Jim_Rogers]

What site are you talking about?
Post a link for me to look at it.

Jim Rogers

[hayton1960]

Hi Jim
The site is a newer version of his old one

www.traditionaltimberframe.com

As far as I can see he has dropped the excellent animated diagrams of how to set out hexagons/septagons/nonagons etc using compasses
I hope this link works OK!

[Tony_T]

Hi Jim
The site is a newer version of his old one

www.traditionaltimberframe.com

As far as I can see he has dropped the excellent animated diagrams of how to set out hexagons/septagons/nonagons etc using compasses
I hope this link works OK!

Jonathan, the animated diagrams are still there:

http://www.traditionaltimberframe.com/ttfv2/index.php?mod=page&ac=page&id_page=4

It's an interesting site but more geometry layout using a compass than actual applications to framing.  It would be nice if there were some animated diagrams of actually laying out framing pieces.  Though I have used some of the things I learned on that site for layout using my compass.

I'll check out the references 34-36 in tfg.  I'm not a member (yet) so not quite sure how I can locate these?  Are they available online?

[hayton1960]

Hello Tony mate
I never had to become a member to get the back issues, I just e-mailed a Mrs Michele Beemer and I got it in the mail soon after. Maybe it is available on a download-I dont know
As I understand it, the traditional French way of setting out relies on using the compass to set out horizontal/vertical/any and all angles for roof pitches etc for the full scale drawing on the floor. Like with decorating or cooking-good preperation is the main part of the job. I think that is why its featured so much on the site. But your right, the actual picage stage where you relate your full scale drawing to your timber and then  mark your mortise positions and tenon shoulders etc, is non existant, in the website and in the tfg articles (I'd still definately recomend those articles though) Maybe you gotta go to one of Marcs courses to proceed further with it?
Cheers Jonathan

[Jim_Rogers]

Tony_T:
You can buy the magazine online, but you can't access the articles online.
If you want the magazine, go to the guild website www.tfguild.org and click on the online store and go to publications, and you should be able to list what back issues you want and purchase them.
Hope this helps.
Jim Rogers

[Jim Haslip]

Hayton,

The (RED) Timber Frame Joinery & Design Book from the Guild has several articles about Hip and Valley Framing written by Ed Levin based on some info from the Compqgnon du Devoir, the French trade guild, using compass layout to determine roof angles instead of Framing Squares. There are 3 articles.

I believe this "RED" book has been superceded by a newer version.
I haven't seen the new one.
Michelle or Sue at the TFG office would be a good place to start looking for a copy.
Ask them if the same articles are in the "Green" book.

[hayton1960]

Hi again Jim
That method of developing roof seat cuts/plumb cuts/hip cuts etc on scaled down paper was the first way I was shown to do roofing calculations (from a stick framing point of view) But I found it inacurate-too much transferring from drawing to bevel board, bevel board to sliding bevel etc too much room for acumulated error. I like to work on a full sale if possible (must be a throwback to my digitising days!!) What I like about the french drawing method is that the floor drawing IS the finished dimension of the component, not a scaled down or abstract representation of it. I think on Marcs site he shows you how to make a giant 360 degree protracter on the floor with a large compass, all the 90 deg, 45 deg, 30 deg etc etc
PS I bought what I thought was a good (Stanley) roofing square-cost me about £24 (about $45-$50) The numbers stamped on it are wrong (some of them are repeated where they shouldnt be!)
Cheers Jonathan

[Jim_Rogers]

Jonathan:
Take that square back, and get a good one.......

Jim:
The new book, the GREEN book has articles in it since the red book was published.

Currently reading it.....
Just picked up my copy at the conference.

Jim Rogers

[Jim_Rogers]

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[Jim_Rogers]

bump

[mmhailey]

This thread is invaluable Jim.  

I am drawing and redesigning ( sketchup) a set of plans I have, and I was in the process of drawing the braces and housings, when I noticed the Tenons are a bit different from the ones depicted in this thread.  Here is a sketchup pic of the two bearing ends.





Am I missing something?  Isn't the one from the plans a lot more work with the chisel, and less bearing surface? The one on the right with the 1 1/2" tenon is from the plans. I do know that this set of plans has no housings and all the dimensions are showing full size timbers 8X8 4X6 etc.

Any one see a problem with changing the braces to housed, and 2" tenon

[Jim_Rogers]

mm:
The reason why one tenon is 2" and the other maybe 1 1/2" could be that the braces are 4" on the 2" tenon and 3" on the 1 1/2" tenon.

Not sure.
But the rule usually is that the tenon on a timber is 1/4 the thickness so if you have a 8x8 then tenon is 2", and a 6x6 the tenon is 1 1/2". But when you're working with 8x8 then usually braces are 4x6 and then they just use a 2" tenon as the layout is already 2" off the layout face and then 2" thick, which puts the tenon flush with the inside of the brace and makes it easy to layout and cut.

When you're working with 6x6's then the braces are usually 3x5 or 3x6 and then the tenon is 1 1/2" so that also make the tenon flush with the inside.

Some people who work with planned timbers so that every side is smooth and have truly 90° corners don't house their timbers or braces. So they just cut a brace to fit flush up against the post or tie beam. So only a mortise is needed, But the cuts have to be prefect or the gap will show, and it' looks like h-e double hockey sticks.....L-L..... Housings hide a lot of imperfections.

Some people like their braces to be centered on the post and one the tie beam so the center the brace tenon and mortise as well.

As I have mentioned and some people don't do this at all, but most frame plans have a set of rules that each joint have to follow, such as creating housings down to the next 1/2" in size smaller inner timber. That is the key to doing "square rule" joinery with rough sawn timbers.

Hope that helps.

Jim Rogers

[mmhailey]

Thanks Jim,

I have redrawn the braces with a 2" tenon, and the 2" bearing surface, and 1/2" housing.





The brace from the plans is a 4X6 into a 8X8 post and tie. The plans show the brace flush with the outside of the frame.
Actually the 1 1/4" brace tenon was the only small one I find. The rest throughout are 2" tenons.

We built this frame when I attended a workshop, and I do remember that the brace stock was planed, probably to an exact 4X6. My guess that is the reason for no housing. 

[witterbound]

IMO, un-housed braces with shoulders on two sides are very difficult to cut and fit.  The shoulders have to be parallel to each other when you are cutting them, then if the timber isn't perfectly square, one shoulder may fit and the other one won't. 
Then if your timber shrinks, it can pull away from the tight shoulder you've fit.    I believe it's much easier to get a clean look by only having one shoulder, and housing it (which isn't that much work to do).

[Mad Professor]

You can lay them out with a divider from irregular wood if needed same as is with posts and ties

Mate them to the posts using the same divider settings using the true post/tie (e.g. a housing).

Best to set up a 3/4/5 triangle on the post and tie to make sure they are square. Use the centerlines and the divider

[Piston]

Jim,
When milling timbers for braces should I mill them 1/8ths inch thicker?  So if I want a 4x6 brace do I mill it 4 1/8thx6?  I think you told me this before but I get confused on which timbers to cut slightly over sized and which ones not to? 

I know you had mentioned to mill certain timbers slightly larger to allow for shrinkage, and I believe the braces were included in that list.  I'm glad this thread came up again. 

[Jim_Rogers]

Jim,
When milling timbers for braces should I mill them 1/8ths inch thicker?  So if I want a 4x6 brace do I mill it 4 1/8thx6?   

Yes, we mill all brace stock thicker then the layout dimensions, that is 2" off the layout face and then 2" thick makes 4" and to allow for width shrinkage, we add 1/8" to make it 4 1/8".
On 1 1/2" by 1 1/2" layout for 3x5 braces we add 1/8" as well.

[Piston]

Thanks Jim....
I think you said that if I had to ask you a third time then you were gonna tell me to get lost!!! That was my second time asking so since it's written down now I should be okay  :D

[Jim_Rogers]

It's, if you ask me a third time, I'll tell you to write it down...... :D :P

[Aikenback]

Hi, in my opinion it seems to me that its most important to use drier wood to avoid gaps. If you don't house the kneebrace you risk the "heel" of the 45 deg. cut opening up as the material shrinks across the grain. The angle appears to become steeper ( over 45deg as the material shrinks towards the "toe". If you house the joint, the housing can shrink away from the housed material and leave a gap. I personally save and use my driest, oldest leftovers and mill them to my brace size and draw bore a little bit with excellent results. I think moisture content is important here. I don't have any experience with oak just yet, is it too hard to work if it is too dry?
Blake

[Mad Professor]

If any body is interested.,

I have the layouts for the top/bottoms of  ( common 45 o braces) braces and the the other sides of how the post and plates mate.  All laid out with a divider.

These are based on several unit circles, with these unit circles, scribed into one of the principal beams as a reference; for construction and future repairs, much like the old buildings were laid out.  The tennons and mortices also had their own circles/diameters for proper layout.

It is all old geometry that most have forgot.  Applying it to irregular timbers/logs requires  references, level and plumb, after you have established a small smooth surface.

[jimdad07]

Great thread, thought it could use a bump.

[Carpenter]

     Thanks for the bump.  I've read this thread 5 or 6 times at least and even laid out and cut several braces and I've still learned something just from re-reading the thread. 

      Could somebody do a tutorial on a 3-4-5 brace layout?  I've been using google sketchup for years, ( but I just recently learned how to really use it) I watched a you-tube tutorial on how to make components for a timber frame building.  He was drawing a Jack Sobon picnic shelter, I happen to have the book with the picnic shelter plans in it as well.  It's in Fourteen Small Timber Frames.  Jack used 3-4-5 braces for this shelter.  Which of course peaked my interest being a carpenter I use the 3-4-5 rule regularly, and I like the way they look.  So, I drew out a rather complex building using 3-4-5 braces, then after downloading Timber Frame Rubies I was able to make shop drawings of the components.  I noticed that with my square rule frame rules of downsizing the frame by 1/2" that the 3/8" layout for the braces did not hold true.  The end of the brace with the 53.2 degree angle is app 3/8" off the reference face, but the end with the 36.8 degree angle is approximately 5/16" off the reference face.  The length is easy of course.  I'm sure I can get the angles right with the framing square.  The dis-advantage might be that once cut, one is definitely left and one is definitely right.  And, do they brace against sideways motion as well as a 45 degree brace? 

     I have not actually cut any 3-4-5 braces or brace pockets yet.  Am I missing something?  That's just what it looks like in the sketchup drawing.  Anyway, I know some of you have cut 3-4-5 braces and could probably help me out. 

     

[Roger Nair]

It's all about choices and priorities.  What you have discovered in the deviations from a 45 degree brace can be worked around.

All braces have handedness, even 45 degree braces, the brace on the left of the post is the mirror image of the post on the right.  Since the ends of a 45 brace are mirror images of each other, the brace just needs to be flipped end to end to fit the pocket.  One option is to cut the brace with a centered tenon with equal shoulders on each side of the tenon eliminates handedness but forces you to a centered layout in the post and beams.  The other option is define handedness and count and cut the braces with handedness.

The other choice relates to brace  pocket depth and the offset of the layout line to the edge of the timber.  I choose to have even depth of brace pocket and layout the post and beams in the manner of Jim's lesson, however as you have noticed the offset from  the brace edge varies with the angle.  So to layout, calculate the offset ( 3/8 and 5/16 by your example).  Mark the offset on one brace end.  With a furring strip and screws filed sharp, set up a fixed trammel at the brace length.  Nestle one end of the trammel in the marked offset and scratch an arc at the other end and the scratch other offset intersecting the arc.  That locates your braces critical dimensions.  In theory, angle layout should be from a line connecting the end points not the edge, so draw the line and do the layout.  Also layout from the edge and compare, you could at this point tweak the angle from the edge if needed.

That is what I basically do.

[Jim_Rogers]

I have attempted to draw, in my professional timber frame design program, a 3-4-5 brace layout.
I doing so I established some rules that I tried to have the joints follow. For example the housings or joints of the brace pockets would be 1/2" under the size of the timber. A standard that I usually use.
Then I drew out the points, one down 4' and one over 3'. I told the program to connect these points with a brace, including tenons and 1/2 housings.
The results gives me a brace which has a 3/8" layout line parallel to the arris of the brace. But the legs of the triangle are not all 3-4-5.
See drawing:



 

The three foot leg comes out a little longer as well as the 5' hypotenuse.

So you have to ask yourself, "what do I want?"

Do I want something that is easy to layout and cut?
Or do I want something that is exact?

If you want exact then you're going to have to adjust your housings depths, angles and brace layout line to the exact locations.

If it was me, I'd do it my way and just tell everyone that it is a 3-4-5 brace layout and no one will be able to see these very minor distance variations.

Jim Rogers
PS or do it Roger's way.

[Roger Nair]

My dad often said, "There are two ways of doing things, the right way or Roger's way."  What I do know is dad was wrong, there are many ways, the manner in which we work as individuals is so varied.  However, Jim, I just do not follow why you deviate from 3-4-5, the goal is to have easy dimensions 3-4-5 and consistent pocket depth and to have the surface of the brace merge with the surface of the post and beam.  What you have outlined fails on two counts.  You need to examine what happens at the joint at a close scale.  The different angles of approach at the joint require a different set back of the critical dimensions, no tweaking of the brace leg will solve the condition unless the tweaking brings you to even brace legs.

[Jim_Rogers]

Roger:
All I'm saying is what the program showed me when I dimensioned the drawing it created.
The drawing is there and if it doesn't work then it doesn't.
I would have to try it to verify that it did or didn't.
But I have found in the past that what the program says is true, it has been true.
Jim Rogers

[Roger Nair]

Jim, your results are based on the way your Jerry program figures problems of slope.  The Germans work on degrees of arc rather than whole number slope.  So what might have happened is that a 4/3 slope is rounded to angles 37 and 53.  the calculation is tan37 times 4 feet equals 3.0142 feet which gets rounded to 3' 1/8" but 3' 5/32"  is closer.  There are rounding errors the true figures are expressed in never ending decimal fractions.

[Jim_Rogers]

Jim, your results are based on the way your Jerry program figures problems of slope.  The Germans work on degrees of arc rather than whole number slope.  So what might have happened is that a 4/3 slope is rounded to angles 37 and 53.  the calculation is arctan37 times 4 feet equals 3.0142 feet which gets rounded to 3' 1/8" but 3' 5/32"  is closer.  There are rounding errors the true figures are expressed in never ending decimal fractions.

This is true, but we have to have number/dimensions we can work with using our regular layout tools.
I have a ruler that has 32nds and 64ths but I rarely use it in timber framing.

Jim Rogers

[Roger Nair]

What is simpler lengths of 3, 4 and 5 and angles expressed as 4/3 slope or a computer program that does not work directly with the bedrock 3-4-5 triangle that spits out fractional answers to whole number solutions.  TRy this, draw the post and beam with half inch deep housings at 3 and 4 foot brace legs.  Then draw a line from the intersection of the shoulder and cheek of the housing from post to beam.  Then draw a line from the surface to shoulder intersection from post to beam.  The two lines are not parallel.  The line from shoulder-cheek intersection represents the true brace length (5') and true slope (4/3).  The method I advocate uses the basic root measurements and accounts for the deviation of the surface of the brace to the layout line and avoids the consequences of a computer program that very few will ever buy or use.

[Jim_Rogers]

I agree with you. The lines are not parallel. I agree with you that this is a program that the average home user will never buy.

My point was that I was trying to show carpenter how it could be done easily with standard methods that I taught him when we were together face to face.

It really doesn't matter if the leg is off by 1/8" or the diagonal off by 1/16" if the angles are right and it looks good, and it is easy to cut and assemble.

Jim Rogers

[Roger Nair]

The importance of the two lines not being parallel is that the surface of the brace will not meet the surfaces of the beam and post in an even manner.  I'm just trying to get closer to a more idealized relationship while remaining simple in scheme.  In the effort to remain simple, normally I specify regular plan and elevation dimensions mostly to the half inch and slopes to whole number ratios.  When I must calculate diagonal lengths and sloping lengths, I rely on a scientific calculator working to .0001" to avoid rounding errors in stringed calculations and converting results to fractional values only at the end.  All my layout is by sharp tools.  I testify that I get reasonable results with less fuss, I follow a discipline of striking lines into wood without tic marks or pencil lines.  I confirm all computer calcs on a scratch pad.  Over forty five years ago as a curious helper, I asked the carpenter I was working for who seemed to pull details out of the air "How do you know that all this is going to go together?"  Earl replied, "It's going to work because I say it's going to work."  Sharp attention, sharp attitude and sharp tools is what will carry a job, those must be made by the carpenter, to rely on a computer that wants to defy the Pythagorean Theorem is not helpful, in a general information format.  Remember the questioner who asked how to deal with 3-4-5 braces that seem to have oddities in layout. 

Sorry, I think I'll rant-rave all the way to the grave.

[Jim_Rogers]

How many times must I tell you that I agree with you.

I'm happy your methods work for you.
My method may not even work for me. I have not tried it, yet.
I may never try it.

I was just trying to help carpenter to understand that it could be possible to layout a brace that looks close to a 3-4-5 brace layout without being exactly 3-4-5 with a method that may work.

You can say all you want that it doesn't work. And I'll agree with you again.

Jim Rogers

[Mad Professor]

I'm sure you can layout 3 4 5 braces using a compass/divider but the layout is going to be more tedious than a 1 1  root 2 braces. 

The sides of the triangle can be measured exactly using turns of a unit circle (compass/divider) and connecting the sides on the brace tie and post, squares the post and tie. 

Laying out the brace mortices and tennons with a divider is going to take some thought.............I'll work on it

[Rougespear]

In my travels through the literature, I see housing depths for 36" braces ranging from 1/2" to 1".  What's the normal/typical/conventional housing depth for 4x6 braces?

[Jim_Rogers]

That will depend on the general frame rules of the frame.
Those should be established up front to tell you what each joint should be/have for a housing.

In Jack's book, he used 1" as he didn't know where in the country or the world that frame would be cut and erected. So to cover all the bases he said 1" but we never do that we just use 1/2"

The 14' x 16' screen porch frame we're working on was drawn as a free standing pavilion and the designer (not me) made all the housings 3/4". Worst mistake ever. There is no 3/4" slot on any "big Al" the old one or the new one. We had to add a 1/4" shim to get to use the "new Al". What a nightmare.

Sometimes housing, like at the post where the tie beam sits, need to be 1" for a larger shelf for the tie beam to sit on.

Jim Rogers

[Roger Nair]

In a strict sense, for square rule. the depth of the  gain relates to the variation in raw timber dimension, however in the practical realm of well sawn stock 1/2 is fairly common.  You just need to survey the stocks min. and max. dimensions  Remember you are not reducing the stock by a constant rather you are correcting the stock at the joint to a common dimension.

[Jim_Rogers]

Yes, I agree with Roger, you're not cutting it a 1/2" under your cutting it to the inside timber. So when we're working with 8x8, the layout is 7 1/2".

Some students would get mad at me when I corrected them and said "where not making housing 1/2 inch".

We're making the timber 7 1/2". As the timber could be bigger or smaller than 8" and that would mean that the housing would be more or less than 1/2".

You really need to think of it as making it 7 1/2". Of course this is when they are all rough sawn timbers.
With planed on all four sides timbers that are true then you can say the housing is 1/2".

Jim Rogers

[Rougespear]

Thanks Jim and Roger.  I asked because I was unsure if the housing was for a bearing ledge (i.e. a necessity for structural reasons), or just a convention of square rule framing - I realize now it is the latter.  Thanks for the clarification.  In hindsight, I assume the "bearing" aspect of the problem is addressed by the bearing nose of the brace.  Understood!

I will be the sawyer and will make sure that my 1/2" square rule (perfect timber within) will account for the max variation in timber dimensions.

Cheers!

[klpauba]

Not to belabor the point, but ...

How about a 30-60-90 degree brace layout instead of a 3-4-5 layout?  I think the program that Jim uses was adjusting the legs of the 3-4-5 triangle so the measurement of the angles were in whole degrees.  This makes sense to me since it would be difficult to layout fractional angles.

Using a 30-60-90 triangle is not that far off of a 3-4-5 (36.87-53.13-90 degree) triangle and has the same advantage as the 45-45-90 degree triangle in that two of the three lengths can be easily calculated (and can be whole numbers) while the remaining is a fractional dimension.  In the 30-60-90 triangle, if the hypotenuse is x, the shorter leg is x/2 and the longer leg is x*sqrt(3)/2.

Maybe the program Jim uses would dimension out this type of brace perfectly since the angles would remain whole numbers (unless he is unable to enter the length of the hypotenuse and shorter leg to force the calculation of the longer leg).

Now, whether the 30-60-90 brace provides adequate reaction to the racking forces in a frame, I cannot answer.

[Roger Nair]

Klpauba, I have no issue with your math, but as a retired lifelong carpenter, I would ask what are the tools of your kit?  If you don't have an alpha square with quadrant or the Orem super square, then it would be better to solve angles by using slope ratios regulated with the common framing square.  A carpenter can frame a building to a high standard without knowing the degree of arc of many significant angles, it's all worked out with slope ratios of right triangles.  If I need to solve framing problems with angles of arc, I use a calculator that handles trig and roots and convert solutions to slope, so I still use the framing square as the regulating tool.  Good luck.

P.S.  I like to take what seems like the most direct path and that is a matter of tools and habit. 

[klpauba]

Klpauba, I have no issue with your math, but as a retired lifelong carpenter, I would ask what are the tools of your kit?  If you don't have an alpha square with quadrant or the Orem super square, then it would be better to solve angles by using slope ratios regulated with the common framing square.
<snip>

No angles involved here.  As I mentioned, a hypotenuse of x and the smaller leg of the triangle is x/2.  Only a framing square is required to lay it out.  It could also be done with only a compass and a straight edge but most of us aren't that primitive.

I appreciate and welcome the dialog!

[Roger Nair]

Your posts seem to be going in different directions.


"How about a 30-60-90 degree brace layout instead of a 3-4-5 layout?  I think the program that Jim uses was adjusting the legs of the 3-4-5 triangle so the measurement of the angles were in whole degrees.  This makes sense to me since it would be difficult to layout fractional angles."

and

"No angles involved here.  As I mentioned, a hypotenuse of x and the smaller leg of the triangle is x/2.  Only a framing square is required to lay it out.  It could also be done with only a compass and a straight edge but most of us aren't that primitive."

So how do you layout the angles on the brace ends?   

[klpauba]

Not two different directions ... two different subjects.

The first was describing why Jim's program didn't allow a 3-4-5 layout because it seems to force whole degrees.  I offered an alternative where you can layout another right triangle that has a special property where the length of the small leg is one half of the length of the hypotenuse.  It just happens that the triangle with this property is a 30-60-90 degree triangle but there is no need to lay it out using the angles.



It might be hard to see but the dimensions of the hypotenuse given in the image above are 6" and the short legs are 3".  The hypotenuse is coincident with the layout line (offset from the edge of the brace in the same manner used when laying out a 45 degree brace).

[Roger Nair]

That is, to me, a new method of angle layout, I will put that into my bag of tricks.

[klpauba]

Roger,

As you mentioned in the discussion with Carpenter (Reply #43-44), using a 3/8 layout line for non-45 degree braces is not ideal.  Assuming the brace will have the smaller leg oriented on the tie beam, an offset of 7/16" is necessary on the end that will go into the post. This will mate closely with a pocket depth of 1/2".  If the layout line offset on the other end (at the beam) is also 7/16", the bearing surface will protrude the same amount (1/2") from that brace pocket.  Your method of fashioning a trammel would allow the protrusion to be eliminated.

Another alternative to the trammel would be to calculate the offset on the beam end of the brace based on the chosen brace length.  For example, a 36" brace (measured on a reference line) would have the post-side offset at 7/16" (at the 0" mark) and a beam-side offset of 1/4" (at the 36" mark).  The layout dimensions for this brace are then: 36" hypotenuse, 18" (36"/2) shorter leg and 31+3/16" longer leg.

I recently cut a mailbox post based on Jim Roger's drawing (at his workshop in Nebraska just last week).  I hope to make another one but with the 30-60-90 brace -- I think that looks a bit more refined.

[klpauba]

For completeness (and for anyone using more primitive methods for laying out joints), this link describes a method to get a 30 degree (or 60 degree) angle using just a straight edge and compass, have a look at http://www-gap.dcs.st-and.ac.uk/~history/HistTopics/Trisecting_an_angle.html (the description is in the third paragraph).  To make the right angle shown in the drawing, use the method described at http://whistleralley.com/construction/c1.htm.

Please note that the method given will trisect a 90 degree angle only -- but is what would be needed for the 30-60-90 degree layout.

[Roger Nair]

For those who might want to layout a plan or pattern board, I suggest bisecting an equilateral triangle.  That should get you there  quickly without much accumulated error, four lines and five sweeps.

[Carpenter]

I did make 3/4/5 braces for a pergola that I built this spring.  It was actually quite simple.  I laid out a few on scrap 2x6s before cutting any joinery. 

Basically, don't worry about the 3/8" layout line.  I use stair buttons and I had them set on the 9" and the 12" mark.  (Here's a little tip, when you use stair buttons don't set the buttons on the mark, set the buttons where the edge of the wood is on the mark, it will be a little different depending on the buttons you are using and the angle).  So, once I had established that, I had both angles already on the framing square.  I wanted a half inch nose off of the reference face.  So I could put the framing square on the timber and draw the nose, (the bearing surface of the brace).  Without moving the framing square I would put a tick mark at the 1/2" mark from the edge of the timber,  then I could slide the framing square to where it matched the tick mark and mark my shoulder cut.  Then I would slide the framing square back the other way until the 3" line matched up with my shoulder cut and that would be my end cut, if I want a 3" tenon on the brace.  (I intended to make a you tube video of this, it might sound confusing but is really quite simple).  To get the length, just measure down the timber and where the half inch nose of the other end of the brace corresponds with your measurement you can lay out the nose of the other end of the brace, and make a tick mark.  Slide the framing square to where it corresponds with that tick mark and mark your shoulder.  And, by this point you've probably already figured out how to get a 3" tenon without taking out the tape measure.  For the length, trammel points as per Roger Nair's suggestion would be best.  I had pretty good results with a tape measure.  You could also step it off with the framing square.


     

[klpauba]

Thanks for the procedure, Carpenter!  It's great to close the loop on the 3-4-5 layout.  I would probably prefer this layout over the 30-60-90 since it's closer to the 45 degree layout with about the same effort.  This is yet another example on how the experience of cutting joints (like yours) trumps intellectual exercises (like mine).

[Ljohnsaw]

I did make 3/4/5 braces for a pergola that I built this spring.  It was actually quite simple.  I laid out a few on scrap 2x6s before cutting any joinery. 

Basically, don't worry about the 3/8" layout line.  I use stair buttons and I had them set on the 9" and the 12" mark.  (Here's a little tip, when you use stair buttons don't set the buttons on the mark, set the buttons where the edge of the wood is on the mark, it will be a little different depending on the buttons you are using and the angle).  So, once I had established that, I had both angles already on the framing square.  I wanted a half inch nose off of the reference face.  So I could put the framing square on the timber and draw the nose, (the bearing surface of the brace).  Without moving the framing square I would put a tick mark at the 1/2" mark from the edge of the timber,  then I could slide the framing square to where it matched the tick mark and mark my shoulder cut.  Then I would slide the framing square back the other way until the 3" line matched up with my shoulder cut and that would be my end cut, if I want a 3" tenon on the brace.  (I intended to make a you tube video of this, it might sound confusing but is really quite simple).  To get the length, just measure down the timber and where the half inch nose of the other end of the brace corresponds with your measurement you can lay out the nose of the other end of the brace, and make a tick mark.  Slide the framing square to where it corresponds with that tick mark and mark your shoulder.  And, by this point you've probably already figured out how to get a 3" tenon without taking out the tape measure.  For the length, trammel points as per Roger Nair's suggestion would be best.  I had pretty good results with a tape measure.  You could also step it off with the framing square.

Please do, I have a LOT of braces to make...

 

[ziggy]

Bumping an oldie but a goodie here... 

Any tips for laying out brace mortises to be flush with the inside face (which is opposite the reference face) of posts and beams? I'm thinking a brace with a single shoulder. I'd like the braces to be to the inside of timbers to be able to install screen (in a frame) flush with the outside of the timbers. Any thoughts on that? 

Oh, square rule and irregular timbers, not mill rule. 

[Jim_Rogers]

Using the measurements from the adjacent face you should be able to create the joint on the inside face. You'll need to be consistent with your offsets. What I mean is if your timbers are over sized by an eight of an inch your mortise location maybe offset from the inside face by 1/8 of an inch.

When we did this frame:


 
The braces were to the inside, for the same reason, and it came out ok.
good luck
Jim Rogers

[ziggy]

Ok nice, I try to avoid measuring off the non-reference face for obvious reasons. Will just have to be careful like you said. Thanks!

[Jim_Rogers]

What I mean to say is that they may not be flush with the inside face. I would measure in a consistent distance on both the posts and the beam to ensure that the mortises match. And you may have a wider housing if the timber is oversized much.

Jim Rogers


 

[ziggy]

Got it. This is off topic, but how are you enclosing the gable ends on the frame in the image you shared? Or will they remain open.

Thanks for the quick replies Jim.

[Jim_Rogers]

I didn't finish off the screen porch; the customer did. So I don't know what he did without asking him to send me a completed picture.
sorry about that.
Jim Rogers

[TimFromNB]

Jim,
About the 1/8th extra thickness you add to braces. I assume you pair down that inner face to 4 inches to get a tight fit? My braces are up to 1/8" under nominal 4" . This will leave a gap in the mortise. Should I layout my mortises at 3 7/8"? I could lay out a 2" mortise 1 7/8" from the reference face?

Thanks,
Tim

[IMERC]

Jim,
Thanks for all the information and your time and effort to write this all up...

[Jim_Rogers]

Jim,
About the 1/8th extra thickness you add to braces. I assume you pair down that inner face to 4 inches to get a tight fit? My braces are up to 1/8" under nominal 4" . This will leave a gap in the mortise. Should I layout my mortises at 3 7/8"? I could lay out a 2" mortise 1 7/8" from the reference face?

Thanks,
Tim

Tim:
Yes, I hand plane down the inner face, the face that is flush with the tenon to make the tenon 2" thick.

My braces are up to 1/8" under nominal 4"

This is exactly why I mill my brace stock over sized.
I would not do a 1 7/8" mortise, I'd still cut it two inch and shim the gap with something that won't show. Your tenon offset has to be 2" off the outside face, so the shim goes on the inside but trim it back so it doesn't show in the mortise.
Jim Rogers

[TimFromNB]

Hi Jim,

Thank you, appreciate the help! Too bad I didn't read this before milling ;D

Will the gap cause any structural problems or is it just aesthetic?

Tim

[Jim_Rogers]

Brace strength is in compression. So the missing 1/8" shouldn't be a problem.
Jim Rogers

[Roger Nair]

There is another option.  Survey the brace material for minimum width.  Lets say it is 3 3/4".  So maintain the 2 plus 2 system, use a 2 inch mortise and tenon with a housing that extends toward the center of the post 1 3/4" beyond the mortise.  Reduce the brace with a 3 3/4" gain at the joint to account for irregularity.  The advantage here is that the outside mortise line becomes reference, the brace becomes fully mortised, no shimming to keep tight m+t and no shrinkage gaps will appear.  Plus centered braces have to my eye a more pleasing appearance.

[MishaZ]

Alright, brining this amazing thread back to life!

I have decided to do my first timber build out of S4S timber to reduce the risk of some of the unknown.

Now that I'm laying out my dimensions, I see that a lot of books I'm reading and post are around rough timber with full dimensions.  The inner timber...

My question is when I am working with S4S timber, should I still go with 1/2" pocket? 

I decided to do 6x6 posts (5-1/2" x 5-1/2"), 6x8 beams (5-1/2" x 7-1/2") and 4x6 braces (3-1/2" x 5-1/2") all in cypress as I'm in FL.  It is all green.

With my post being 5-1/2" wide and having two braces terminate in to it on two sides at 90, my other question is about length of the tenon.  Most books have them at 3", it obviously would not work as they would be too long.  What are some good rules when it comes to the tenon length.

[Jim_Rogers]

Usually, two braces joining on post at 90 degrees angles are at different elevations. This prevents the issue you are having.
However, in your case, you need to figure out which one bears the most weight and make that one the long one.
Or trim both equally.
Braces strengths are in compression. So, the more bearing surface at the shoulder and bearing end are the important factors to consider.

Even if all timbers are S4S the joint still can be/could be housed to 1/2" under. And tenons have to be figured for those details.

Good luck with your decision.

Jim Rogers