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Standard Procedures for Timber Framing

Started by Jim_Rogers, January 03, 2005, 10:16:25 AM

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Jim_Rogers

Standard Procedures for Timber Framing

I feel there is a need for creating a list of standard procedures and methods for Timber Framing.

First of all before you order any timbers from your sawmill, you need a timber list. If you are milling your own timbers with your own mill or buying them from your local lumber yard you have to know what sizes and lengths you will need to construct your intended frame.

I've heard of owner builders who ordered a stack of timbers and then called a timber frame designer and said: "design me an addition to my house using these timbers." This is not the best way to get a good design or utilize our timber resource correctly.

Now to design a frame there can be many factors that need to be taken into consideration. One of them is what is the need of the owner. Is it shelter as they need a home? Is it storage for animals as they need a barn? Or is it a place to store some personal items such as a shed?

The intended need will determine the size and shape of the structure. We can get into how to design a frame for each of these needs in detail later in another story.

Once the space requirements have been met and the frame is designed, a stock list can be generated. Now a stock list is not a timber list. The difference is that a stock list may have listed on it 50 braces 4' long. But a timber list will show the same line as 25 pieces 10' long, as you can cut two braces 4' long from one piece 10' long. Now why wouldn't you cut two 4' braces from one 8' piece of lumber? The reason is that you may need to shift the layout of the brace toward one end of the piece or the other in order to eliminate some defects, such as knots, that will fall right where the joinery will be cut. Knots in the tenon areas will weaken the joint.

Before any timbers are cut or raised all of the types of joints to be used in the frame need to be designed and verified that they are correct for that location and load. A timber frame designer should be able to accurately design the type of joint needed for each location in the frame. A designer's training and experience should qualify him or her to design your frame, but a structural engineer familiar with timber framing may be needed to verify whether or not the timber size or joint will carry the intended load.

Buying a stock plan, of the shelf, for a 24' x 36' barn may work in an area where the snow load is 30 lbs. per square foot but not in an area where the snow load is 60 lbs. per square foot or more. Each design has to be analyzed for its intended location in the country.

Ok, so your design is done, your frame has been analyzed and passes, your timbers have been ordered and delivered. Storing your timbers is very important to make them stay straight and true.

More next post......
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Jim_Rogers

Part two:

Stacking and sticking your timbers are very important, and you should learn how to do it correctly if you don’t know how. This subject has been discussed here before and you should be able to find a thread about this subject and read up on it and get a good understanding of how it should be done.

Now that you have your timbers stacked and you’re ready to start cutting joints you should try and cut as many similar joints as possible to save time.

What I mean is that if you have six posts to cut a stub tenon on the bottom for connecting to your sills or other support systems, you should line up all six on a set of bunks or cribs so that all six have the bottoms on one side of the crib. You then layout all the stub tenons, one on each post. Then when you set your skill saw for the shoulder depth, you can cut the first post, and move to the next post and make that cut. Then move to the third post and make that cut. And continue this process down the whole line of posts and proceed to make all the similar cuts, before changing the saw depth setting. That way you’re making good progress on many timbers at the same time.

Once you have all your joints cut on one timber, or more if you’re cutting in a “production” mode you should treat your timber ends, including all the joints, with some end sealer to prevent them from drying out to fast. The standard end sealer is a type of wax-based paint and this wax will help the joints slide together later, when you’re ready to assemble your frame.

As you are cutting your joints and if you’re going to assemble your frame using the “draw bore” method you could drill all the peg holes through the mortises, but not through the tenons. If you anticipate the frame sitting for several months before it’s going to be raised you might postpone the boring of all holes until you’re about ready to raise the frame.

Once all your joints are cut on all timbers, the next step is to do a full frame fit up. A full frame fit up is when you test every piece into every corresponding joint. This will insure that each tenon will fit into it’s intended mortise, correctly and completely. At this time, if you haven’t bored all your mortise holes yet, you could drill them now. Then as you fit up your tenons into their mortises you can insert the drill bit through the mortise peg hole and cause the drill bit tip to poke the tenon to indicate the exact point where the peg hole should be drilled. Again, if you are draw boring, then you could use this poke point as the starting point for your offset hole. And if all your measurements check out correctly and your frame is straight, square and true to the design and/or you’ve made all the adjustments to the tenons and tenon timber shoulders so that the frame is aligned correctly, you can drill your tenon holes with draw bore or not.

One way to do this is to line up all your timbers that will make up a broad wall first. A broad wall is the wall that is the long short side wall of the structure, not the gable walls, and usually but not always, not the bents. After you have done one of the two broad walls, you disassemble this wall and do the other one. Stacking your pieces away, some place close by for the future raising. Then after you have done the same procedure to the second broad wall, you start with the bents.

If you have space and you are about to raise your frame you could leave the bents assembled and maybe even stacked.

More next post.....
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Jim_Rogers

Part three:

Standard procedure is to drill all holes from the layout side of the timber. And also you should drive all pegs in from the layout side of the timber.
This can present some problems, sometimes, if the second gable bent can't be assembled with the layout side up, what you might have to do is to assemble it with the layout side down. But if so, you could do it up on saw horses and someone has to lie down on the deck or ground and drive the pegs up into the frame.

If you follow these procedures, you'll have every joint tested and bored before your crane or raising crew shows up on raising day.

And then there shouldn't be a need to have a chisel on the deck during the raising. A chisel dropped from someone's tool belt from up on the frame can be a very dangerous situation.

During your full frame fit up you can number or letter each joint part with unique symbols, letters, or markings. What we commonly do is to test a tenon into a mortise and if it fits, and the holes are bored and everything is correct, as we pull them apart we mark on the tenon and in the mortise or on the mortise housing a symbol for that joint. This symbol can be a triangle, a square, a diamond, a half moon, or some such unique symbol. It's quite easy to swap posts from one side of the building to the other as they might look identical. We've found that tie beams can seem very much the same end to end.

But during assembly if you see a half moon tenon going into a mortise with a square on it, you'll know right away something is wrong. Even a beginner will see this if you don't. And ask you: "why does this tenon have a triangle with three lines through it and it's going into this mortise which has a circle with a square in it?" This should tell you right off, that's something is wrong and you need to look at it and figure out why, and what is going wrong.

No timber should be raised that doesn't have all joints cut on it. One way to insure that this happens is to create a checklist for the frame. I use a check list now and it works like this.
You have a list of timbers for the frame. Each bent has a certain number of pieces. Such as in bent one you may have a  south post, one middle post and one north side post. A tie beam, and four braces. Under south post, you'll have a stub tenon, for connecting to the sill, a top tenon for connecting to the plate, and a through mortise for the tie beam. You may also have three brace mortises, one for the tie beam and two opposing brace pockets mortises for two braces going from the post to the plate.
Your list would look like this:
      South Post
            Stub tenon
            Top tenon
            Tie mortise
            Tie brace mortise
            Plate mortise 1
            Plate mortise 2.

More next post.....
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Jim_Rogers

Part four:

And as you complete one joint on this timber you check it off as done. Like this:
South Post
            Stub tenon   Done
            Top tenon    Done
            Tie mortise  Done
            Tie brace mortise Half done....
            Plate mortise 1 laid out
            Plate mortise 2 laid out.

And if you need to you can even brake down each joint more. For example:

Plate mortise 1
      mortise
      housing
      peg hole
Plate mortise 2
      mortise
      housing
      peg hole

I've been to a frame raising before where we had to stop the raising as some joints weren't finished. The owner/timber framer said he was working on that timber one day and then didn't finish it and when he came back to work on his frame several days later, he had forgot where he was and didn't finish that joint. And as he hadn't done a full frame fit up this error or omission hadn't been found, until it was needed. It's quite a site to see the crane and a whole raising crew of 15 men standing around for 15 minutes or more as a mortise and housing are being cut by one frantic timber framer/owner.

No frame should be raised without all the joints that will be used having been designed. You don't want to try and figure out "how are we going to attach these rafters now?" Being up on a ladder trying to cut a joint in place is quite difficult to do, let alone be dangerous.

One of the many things that influence a design is the method of raising. The order in which the parts are to be raised can sometimes also influence the design.

The procedure for raising a frame should be well thought out and most often even written down. This procedure list is called a "raising script." Having a written script on hand is great to follow and copies can be made to give out to crew leaders and maybe even to the crane operator. If the crane operator sees some move coming up on the script that will interfere with another move or lift coming later in the procedure, he can point it out and make adjustments to the plan. If a bundle of floor joists is going to be set on the tie beams to be spread out to create the second floor, you don't want to install all the rafters first, thereby blocking the path of the bundle of floor joists.
Some crane operators are very experienced in raising timber frames and can show you time saving tips to make the job go smoother and faster, such as lifting all the floor joists in one bundle instead of piece by piece.

So the script has to be somewhat flexible and you can allow some changes based on certain circumstances.

Each frame is different. Each location is different. With all these variations some order has to be drawn up and prepared to insure the completion of the project. This again, can be a flexible plan that can be customized for the day, the frame or the workers.

A very experienced timber framer told me more than once: "it's 80% planning and 20% execution!"

I hope this story has helped you to think ahead and plan your job of creating your frame.

Jim Rogers

PS. These are my opinions and I welcome input from others.
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Jeff

Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

Mathias

Thanks a lot for all the information, Jim!

I'm in the process of reading all your old posts. There's a lot of great info you have shared and I really appreciate all your time and effort on this great forum.

I plan on starting on a timber frame barn in the spring.

I'll probably have a question or two for you as I get in the thick of it.
Hand plane collector

JoeyLowe

Excellent advice for anyone.  This post seems to be directed at me! ;D   Afterall, I did already have quite a few beams cut without knowing for sure what sizes or how many I would need.  Not to fear though.  Once you get started, alot of questions tend to answer themselves.

One piece of advice that I can offer is the importance of a trial fit before standing up a bent.  Can be quite dangerous and humbling to modify or cut a joint while perched up in the air.  

Another piece of advice that I can offer is the importance of understanding the end result that you are trying accomplish.  For example, one beam or post can have many different mortices cut into it.  If you can't visualize what each joint is for, it is real easy to forget them or cut them in the wrong place.  

Thinking in 3D can be very different from ordinary framing.  Working drawings can really help here.  What I mean by working drawings (some refer to them as shop drawings) is a drawing where only one beam or post is displayed and all sides are drawn and labeled so that it becomes very clear what joint belongs where.

--
Joey Lowe

"Working towards perfection has to be a part of anything one does.  You've got to put yourself into it." ... Sam Maloof (chairmaker)

Jim_Rogers

To Joey Lowe:
This series of posts were not directed at you, personally. If I have offended you, I'm sorry.

But if was for all beginners and others who are interested in timber framing.

There maybe some points that you feel apply to you, and they may also apply to a lot of others who read this forum, and do not post.

We all learn from our mistakes and if one of our mistakes can teach another person how to not make the same mistake, then we can find some good in our own affairs.

Every frame is a learning experience.

Every frame raising is a learning experience.

Passing on these experiences helps others to learn.

I get a lot of personal emails from framers asking me questions and advice on how to help them with their problems or situation, and this type of planning story should/could help them to understand the whole process from beginning to end.

That was the intent of the story/posts.

Jim Rogers
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Captain

Thanks for the inspiration, Jim.

I'm reading my first Sobon book now.

Captain

JoeyLowe

Hey Jim:

No offense taken here.  I was just remarking that a lot of what you said applied directly to my situation.  

For example, here is another tidbit of advice learned the hard way. Brace pockets, whether they are 30" or 36" or whatever length,  should be the same length for each leg.  Otherwise, you won't have 45 degree angles.  Likewise, if the angles are different, than the brace pockets need to match.  I learned this the hardway.  Awhile back, I was cutting my girts that join my bents.  I placed the brace pockets at 36",  and did not pay attention that the post brace pockets were placed at 30".  Needless to say, the braces didn't fit.  So, I calculated the new length along with the new angles to compensate for the different leg lengths.  Still didn't work, because the brace pocket angles were off too.  So guess what?  The girts had to be re-cut so that the brace legs matched the post legs.  Lost an entire morning on that little exercise.

Jim, keep posting the stories.  They really do help! 8)
--
Joey Lowe

"Working towards perfection has to be a part of anything one does.  You've got to put yourself into it." ... Sam Maloof (chairmaker)

DanG

Jim, I've read, and kept up with this informative thread. The only thing I can suggest, now that I've brought it back to the top, is that you make it a sticky thread, so it will be available even when there are no recent responses. :)
"I don't feel like an old man.  I feel like a young man who has something wrong with him."  Dick Cavett
"Beat not thy sword into a plowshare, rather beat the sword of thine enemy into a plowshare."

Jim_Rogers

Thanks DanG, I'll consider it......

Jim Rogers
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Jim_Rogers

Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

metalspinner

The sign of a good teacher is that the pupil thinks he can go on out and get it done.  You make it sound soooo easy.

smiley_headscratch  Where is my mallet and chisel?
I do what the little voices in my wife's head tell me to do.

Stumpkin

Jim, the idea of a checklist is a great way to track progress on any project. I use a spreadsheet program to keep track of my time spent cutting each type of joint or stick (brace, joist, rafter, etc.) I can then use the SS to estimate the amount of time needed to finish cutting the frame or to see if I'm still on schedule for the raising. Tom
"Do we know what we're doing and why?"
"No"
"Do we care?"
"We'll work it all out as we go along. Let our practice form our doctrine, thus assuring precise theoretical coherence."      Ed Abbey

Jasperfield

Boy, this a pretty impressive post. I'm printing it out to use in the future.

I'm really glad you wrote it...and I found it.

zopi

Couple of things I'd like to add here..

Which is funny, as I have never built a timber frame..Soon I hope..

However, I do alot of very expensive and very delicate quality assurance work in the submarine navy, and I have some suggestions for work lists and procedures..

First, and this may sound dumb..but it is a cardinal rule, write the procedure so that the craftsman can understand it..it's easy to get too technical..
Organize the job in phases..if the building is complex or the raising will take more than one shift, plan phases so that work can be safely stopped without risk to life or the frame..IE a bent won't blow over during the night...and so that nothing is forgotten.

Hold a brief (meeting) prior to the job, in which everyone involved in the raising must be present (even the cook..) so that everyone knows what the safety guidelines are, and what the specific plan of attack is, and without any doubt who is absolutely in charge...
Hold a brief (meeting) prior to each shift so that every one knows where the process is and what has to be accomplished today..

The checklists are a great idea..component by component, and joint by joint...but I would suggest having an independent
person who isn't directly involved with the work verify each piece..even if they don't know anything about the work..you might have to explain each piece to them...before the work starts..or this could be a part of the pre job brief..

independent eyes save alot of snafus...

Take all this for what it is worth, most of it is overkill for a simple structure, but it is all sound work practice..and can save alot of trouble..

Got Wood?
LT-15G GO chassis added.
WM sharpener and setter
And lots of junk.

Jim_Rogers

zopi:
Thanks for your input....

Jim Rogers
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

zopi

No problem..Thanks for adding the (Meeting) in my post..sometimes you speak one language and for get other folks don't <G>
I am enjoying your tutorials...yer the first one who has explained square rule joinery to where I could understand it...
Got Wood?
LT-15G GO chassis added.
WM sharpener and setter
And lots of junk.

Jim_Rogers

You learn more by doing it, and then even more when you try and teach it to someone else......
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

zopi

Yep...Best way of learning is teaching...hopefully after I get my little smokehouse done to where I can organize and use my tools...then I'll set up and timber frame another shed..probably a 10x 14
storage building...
Got Wood?
LT-15G GO chassis added.
WM sharpener and setter
And lots of junk.

Bandmill Bandit

Great Thread
I Have learned a lot.

My wife wants me to build a 2 storey play house for the inevitable grand kids and wants it to be a timber frame rustic little house. Foot print will be about 10 by 16 ish or what ever comes close.  It will be built by this German guy that has bit of a reputation for building things so it aint comin apart in this life time or the next, will support at least the weight of full grown cow and will simply change locations should a tornado strike. If any one has a plan or knows where i can get one please let me know.


Skilled Master Sawyer. "Skilled labour don't come cheap. Cheap labour dont come skilled!
2018 F150 FX4, Husqvarna 340, 2 Logright 36 inch cant hooks and a bunch of stuff I built myself

Just Me

 I have done a few small timber frame structures, am self taught with the help of a few books, and I appreciate what has been written here.

One thing I might add is that for repetitive pieces such as braces I make masonite templates that I hang from the shop rafters until such time as they come in handy again.

Larry

Neophyte

Thanks Jim,

I am framing your procedures for when I start timber framing my 2 story colonial....


Magicman

Welcome to the Forestry Forum, Neophyte.   8)
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

It's Weird being the Same Age as Old People

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

flyingparks

Thanks Jim. A lot of questions I have asked are answered right here. I'm fortunate to have found this. Thanks again...

IMERC

Who ever invented work didn't know how to fish.... Here fishy fishy....

sterling08

Jim has provided so much good information on this site that it is amazing! I think that we should start a petition to see if we can convince him to consolidate all his rules of thumbs, and other useful information, into one Word or PDF document, or possibly even a book. I would be willing to pay a lot of money to purchase a document that captures much of Jim's knowledge and words of wisdom!

The forum is great for individual topics, but it is not the most convenient for amassing a large collection of instructive information into one concise location.

Jim_Rogers

Thanks for all your kind words.
What I need is for everyone to go to YouTube and subscribe to my videos. I need to have a 1000 subscribers in order to make money off them.
I want to do more videos, but I have to work to pay the bills. Getting paid for making videos about timber framing would be fun not work.
Jim Rogers
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

D L Bahler

JimRogers117 - YouTube

Here's a link for everyone to subscribe to Jim's channel 

Jim_Rogers

Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

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