Timberframe joinery specs

there is a member on L/Js sister site WoodWorkingTalk
named “Jay C. White Cloud” that does this type of building for a living.
he would be more than glad to assist you in a safe and workable design.
(if you want to broaden your options).

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-- I am a painter. That's what I do. I paint things --

I am sure there are sites around the web that have the information you are looking for. I have never searched them out. I have needed that type of information on a few of my builds. For that type of information I have turned to my half dozen timber framing books. By far the best one for this type of information is Tedd Benson’s book “Building The Timber Frame House”. He devotes a large part of the content to design strength, you can’t find a better guide. The appendices has pages of formulas and tables to help you avoid doing the math, tables cover oak beams, douglas fir, spruce, and pine. It was published in 1980 by Charles Scribner’s And Sons. If like me you prefer a hard copy at your finger tips, you can probably find it on E-Bay or Amazon.

I can tell you off the top of my head that a 29.5’ unsupported span, supporting a work space above is not doable with a reasonable beam size, but I don’t know what you have available for material.

-- "There are no utopias, chaos theory reigns, anyone who says different is selling you something"

Hi Will,

I got your message on the other site and thanks to Brother John for suggesting my help…I do love this craft and teaching the traditional arts! Blessings for that John!

willhime wrote:

”...I m trying to research timberframe joinery to make a mezzanine for my shop. The back area of the shop where I want it to go is 29.5 long by 12 wide…”

More than achievable even for a novice Timberwright…This won’t be much different than building a giant Harvest or Farmer’s Table with the joinery just being larger in size and context…

willhime wrote:

”...Ideally I would like to have no center beam so it s a completely open in the middle to still use my table saw and general spacious work area almost the same as it is now…”

I may need some help understanding you on this point?

When you say “beam” do you actually mean a “center post.” If that is the case than you are spanning nearly 30 feet!!!

That is going to take one very large timber (aka Girt, Beant Beam, Summner, Hari 梁, etc) and/or some tricky joinery and design work to achieve…but it too is achievable…IT IS!!!...going to be more difficult and challenging for a novice comparatively to having a center post and only spanning ~ 15’.

willhime wrote:

”...What I m having trouble finding is knowing what dimensions of beam lumber I ll need for such an expanse with no middle support. Is there a place online for a sort of calculator that ll tell me my necessary lumber dimensions and wood species requirements ? I m good at joinery and building normal structures but am doing timberframe for the first time.
“

No…Not really. There is no real source (*or one worth trusting!) nor can there really be one past experience and knowledge as the number of variables is too great…

This is because we are talking about “green wood” and it does not fit into “most” construction tables for span timber sizing calculators you find on the internet, nor do most give this information out for liability reasons.

There are sources for doing the math your self, but that takes a great deal of skill and understanding of the craft when applying to “live load” scenario applications and the use of green wood too. I’ve been doing this on and off for over 40 plus years (traditional trained) and full time for over the past 20 years, and even with that I still have my designs checked by a team of PE that I have worked with for almost that entire time. As such, its a small fee for a project your size and worth the expense unless you fine with just “winging it” and trusting some “geek” like me on the web? I hold not liability in you choice and do recommend a PE to oversee your or a collective design…

willhime wrote:

”...To make this happen I m okay with going super bulky on the sides and cross beams…”

O.K!

On the cross beam (aka bent beam) you will have to or do a built up style beam like a “Keyed Beam” to handle that span and the live load/dead load above. the “side beams” (???) won’t have to be that large at all as these are just Joist in this application…

willhime wrote:

”... I m trying to make an area where I can wall it out on top and turn it into an office and a CNC area if that helps clarify my load bearing goals…”

Yes, that does help but I would still need to know (understand) full dead and live load parameters to even begin guessing at what you Bent Beam needs to be in size. Species of wood you intend on using is also a factor, along with grade of the timber and where you plan on purchasing it unless you are hewing/milling it yourself…

I see your in Austin, Texas so will need to know how you plan on sourcing your timbers. I might be able to help there as I do work in Texas (Katty, etc) once a year or so. There are folks on ForestryForum, Lumberjocks and else where that might help source a good Sawyer for you too.

I’m on a timber frame project in Vermont now and not near the web until tomorrow back in New York state. I just stopped off to “shoot out” some emails and respond to folks like you so be patient if it takes me a while to respond to you. Feel free to send me an email if you wish to also, and if you “Google” my name in quotes “Jay C. White Cloud” you can get a lot more info about my work, who I work with and projects I have done. I look forward to being of any help I can.

Warm Regards,

j

Ha, Ha…Beam Size…what you asked about…You are not going to get this smaller than 16” deep and 8” wide in most species and probably larger for your suggested load parameters…That’s a good starting point…but there are some “tricks” to getting this down in size by design and other means…

-- (http://about.me/tosatomo) Confucius: "...I hear and I forget. I see and I remember. I do and I understand..." Socrates: “I cannot teach anybody anything. I can only help them think..."

Damn… what a fantastic forum we have here guys. Just wanted to bask in how helpful folks can be here
Carry on

Ditto.

whitecloud, bless you for sharing.

-- Think safe, be safe

welcome aboard, Jay !!
hope you can drop by from time to time.

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-- I am a painter. That's what I do. I paint things --

Hi John,

I shall!

I’ve been a member since 2010 but never came across topics that often which fit my “wheel house” of skill sets. As such, I’ve never been that active here, but it is a great forum I have found over the years when I do “check in.”

Please!!!...do also feel free (or any reader for that matter) to reach out if there is ever a topic anyone feels I can be of value or service to within my experience as a traditional (working) woodworker, Timber-Barn Wright, or anything dealing with green woodworking, natural-traditional building modalities or the related “old life-skill arts.”

Blessings to you and all here,

j

-- (http://about.me/tosatomo) Confucius: "...I hear and I forget. I see and I remember. I do and I understand..." Socrates: “I cannot teach anybody anything. I can only help them think..."

Thanks Jay for the selflessly thoughtful reply. And to Carlos for the book recommendation. It is in the mail right now. So Jay, yes, I did mean center post. I’m not familiar with all the vernacular… yet. I’m including a sketchup of the basic design I think I need but feel free to tear it apart where need be. If I’m going to put an enclosed office on top I’m assuming you’re recommeding the center post as in the samurai's video

A keyed beam sounds interesting. I usually try to always make my next personal project the hardest thing I’ve done. Being pretty good at joinery in regards to funiture and door making is what drew me to this over just a welded solution. I assume the cross joists will be drop in mortises. If you think this undertaking is too risky not to have a center beam then maybe I’ll concede to another post in my workspace. I would be a pretty big bummer for an office and cnc machine to fall from 10’ in the air. Another query I had was how to secure the posts to the concrete floor. Should I do a plate style that has a steel tenon going up in the middle of the post about a foot or so or is there a better solution for this? From what I’m gathering, fir and oak are the preferred species unless I use pine 6×8’s from the box store and double up in certain areas. My other option is a salvage yard close to my house where a guy has about 100 acres of random metal beams, street posts, large wood timbers, staircases, etc. Or, there’s a sawyer about 20 mins from me that I might go visit if box store beams are out of the question. Thanks for taking the time to sit through all my yammering.

-- Burn your fire for no witness

willhime wrote:

”...Thanks Jay for the selflessly thoughtful reply. And to Carlos for the book recommendation. ...”

You are most welcome, and I believe you will find Ted’s book insightful. I do have it on my reading list for students, but it comes with observations and feedback. It’s informative, yet out of context in some regards and not often easy to interpret and/or extrapolate even for an advanced woodworker to garner all they need. Still worth the read for sure!

willhime wrote:

”...So Jay, yes, I did mean center post. I m not familiar with all the vernacular… yet. ...”

Good…but I did not want to assume anything. The nomenclature of the craft is regional and cultural so don’t worry at all about not getting it all down. I’m up to speed on much of it (even in Korean, Chinese and Japanese) and I still get thrown curve balls all the time…LOL!!!

willhime wrote:

”...I m including a sketchup of the basic design I think I need but feel free to tear it apart where need be. If I m going to put an enclosed office on top I m assuming you re recommeding the center post as in the samurai s video ...”

Thank you for the sketchup…!!!...If you wish, send me a file link to my email address and I will have a closer look and comments later this week perhaps if I can get back to an area with WiFi. What is seen in Samurai video is not really something I would design or build…but yes, something like that. I don’t follow or recommend his approach to things too often as I don’t find many…(not all)...of the “YouTube Experts” worth much to recommend. Mr. Chickadee (to me) is one of the very best out there, if one wants to watch and gain inspiration…but that is just my opinion to be sure…LOL

willhime wrote:

”...A keyed beam sounds interesting. I usually try to always make my next personal project the hardest thing I ve done. Being pretty good at joinery in regards to funiture and door making is what drew me to this over just a welded solution. ...”

A keyed beam is one of several applicable solutions and once I can review your drawing I can perhaps give more examples and feedback?

willhime wrote:

”...I assume the cross joists will be drop in mortises. ...”

Maybe…???...but they can also sit on top, go in the other direction (Japanese style 根太 Nebuto or Neda) and even obliquely…just to name a few of the possible approach modalities for the joist configurations…

willhime wrote:

”...If you think this undertaking is too risky not to have a center beam then maybe I ll concede to another post in my workspace. ...”

GOSH NO…Brother…?!!!?

Don’t give up yet on your plan and desires for it. You (just like my clients and students) set the parameters of the challenge and my obligation is to give you the most diverse and succinct choices to address the challenge…Then, you choose.

A PE approval is still recommend, and I would be remiss not to repeat that. It is your choice thought to take this on without there oversight and I do the same for my own personal work too….but…even then they often add there 2¢…LOL!!!

​ ​

willhime wrote:

”...Another query I had was how to secure the posts to the concrete floor. Should I do a plate style that has a steel tenon going up in the middle of the post about a foot or so or is there a better solution for this?

...”

I need to know what is under the floor, how thick the slab is and will say that in this situation, my style is a stone boulder of germane size (to spread load) and the post scribe fit to it with just a drift pin. Often the current slab has to be cut away to place a proper footing for the point load, but that all depends on the “point load” and the quality of the slab?

​

willhime wrote:

”...From what I m gathering, fir and oak are the preferred species unless I use pine 6×8 s from the box store and double up in certain areas. My other option is a salvage yard close to my house where a guy has about 100 acres of random metal beams, street posts, large wood timbers, staircases, etc. Or, there s a sawyer about 20 mins from me that I might go visit if box store beams are out of the question. Thanks for taking the time to sit through all my yammering. ! ...”

Oak, Pine, Fir, all can be made to work…

A tree company from your area may find you some nice timber too. Contacting Woodmizer or the other “remote sawyer” groups can also get you what you need…

I look forward to you email and that file…

-- (http://about.me/tosatomo) Confucius: "...I hear and I forget. I see and I remember. I do and I understand..." Socrates: “I cannot teach anybody anything. I can only help them think..."

I’m thinking glue lams

Glue Lams would take this into the modern context and more “Post and Beam” style work of modernity…not traditional timber framing in any way.

However that is an option to be sure if one likes that style of work and has the funds to purchase those engineered timbers, which are not inexpensive at all!!!

-- (http://about.me/tosatomo) Confucius: "...I hear and I forget. I see and I remember. I do and I understand..." Socrates: “I cannot teach anybody anything. I can only help them think..."

yep. it’s going to be expensive no matter what route you go.
I see a post in his future.
But, I’ll wait and see what you come up with. I’m definitely no expert or even close to.

I’m not sure on the post yet at all…at least not in the center, and only then if other options like a keyed beam or truss are not chosen…

Cost, for me, at this juncture in the design process is extreme speculation at best and very dependant on the OP’s collective skill sets, creativity, and gumption…to be sure.

I have done project (or at least overseen them) where the cost has been less than a trip to a “big box store” while in other cases, where the DIYer is more “dreamer” than “doer” the cost is extreme and more than it should be…

So, with that, this project could cost less than virtually nothing fiscally or….???...it all depends. I (and those of us in this line of work) seldom pay more than a $1 per board foot on average…when…we actually purchase lumber and not the trees themselves. For most DIY projects I secure lumber for free or next to free depending on context. I will need to know a lot more about the local resources of the OP and his drive before even beginning to speculate how much (or how little) this will cost…other than time, but that’s the fun part…LOL!!!

-- (http://about.me/tosatomo) Confucius: "...I hear and I forget. I see and I remember. I do and I understand..." Socrates: “I cannot teach anybody anything. I can only help them think..."

I emailed the sketchup files.

As far as cost goes, I have some extra money to speed things up, but I’m also a collector and scavenger of neglected lumber. Living on 12 acres, there’s plenty of room to store random findings that I’ll sometimes pick up on my 18’ trailer. I’m not opposed to glue lams but they’d be from my own stock of large old decks and fences. I am a fan of modern and asian as well as arts and crafts and traditional english and bounce between stylesI have family in the San Juan islands near vancouver so timber structures are very nostalgic to me. I generally almost never buy wood unless it’s for a client. Sometimes not even then. Just finished a shed for a lady out of deck wood that got sugi ban’d which is a nice cover technique. You can take a somewhere between stain grade and paint grade approach. I’m usually a mixture of dreamer and doer, which ends up taking far longer than I expected. I’ll shoot my mouth off about how awesome something’s going to be then realize I just signed myself up for 50% more work. Still haven’t learned my lesson on that.
As far as the slab goes, one side of the shop shows concrete over 2’ thick, but the previous owner said the slab is 4” thick? I’m not really familiar with the ins and outs of slab talk, but that seems a tad paltry to me.

-- Burn your fire for no witness

That sounds typical of a slab foundation, common were frost ground penetration is low. The outside edge is thicker and stronger but does not have to go too deep. The thickened edge provides the strength for your bearing walls, the rest of the floor can be reduced to a 4”slab, 6 or 8” for industrial buildings usually. Internal supports usually rest on a square that also goes deeper than the slab but it looks like your shop is all clear span. Something like this.

-- "There are no utopias, chaos theory reigns, anyone who says different is selling you something"