*
I would like to use an exposed timber frame with steel connectors and lateral bracing. Does anyone know of someone making steel bolt and plate connectors for this type of construction. The design of these connectors and bracing needs to be pleasing to the eye, not simply a Simpson joist hanger for example. thanks in advance
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
Fine Homebuilding's editorial director has some fun news to share.
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
*
What would be really cool if you need/want metal connectors
is to find a local blacksmith shop if you can, and work out
a design. Some welding shops may be of help too.
Question-why do you want the metal? Too much span, and you
don't want posts, or partitions?
Where are you located? Are you a timber framer?
MD
*****
*I am also interested in using heavy duty metal connectors made from steel plate to connect timbers in post and beam construction. This is largely because I have the equipment to cut and drill the steel plate but I don't feel that I have the expertise, and definitely don't have the experience, to do traditional timber frame joinery. Also, a lodge that I once visited had this style of construction in a large meeting room and I liked the looks of it. My problem is finding resource materials from which to calculate the size of the metal plates and the size and spacing of the bolts through the timbers. I have several timber framing books (Tedd Benson, Sobon, and Sobon & Schroeder)but they all describe traditional timber framing joinery without any information on heavy steel connections. Can anyone point me toward any resources that will allow me to correctly design these connectors?
*
your connection needs to be engineered, grade of steel called out, size of welds (if any), dimensions of all holes, sizes and grades of bolts, and all critical edge distances called out in
b both
the timber and the steel.
A licensed engineer should be able to provide drawings which can be taken to a
b competent
fab shop.
fred matthews, PE
*
Casey,
I hope you don't think me a jerk if I say that using the metal connectors in place of traditional timber framing joinery is pretty much missing the point of going back to old world basics and craftsmanship. The look is important, but all that metal will cost you more than spending a week or two at a timber framing school, and it is a blast doing the work. I'm not an expert. I do it to learn a skill, mostly as a hobby right now, an alternative to stick building that I do as a job. But it really isn't as difficult as you may think. I chainsaw logs into squared sides, usually rectangular, then plane them off, and follow Sobin's directions-remember that most mortise and tenon joints allow some imperfection, covered up anyway.
If you have access to timbers, especially those that are already squared up, so much the better. My way certainly is not for everyone, and if you demand perfection with as little waste as possible, a sawmill will be much better.
I think it would be a lot more satisfying to do the real thing than to have all that metal and not nearly as beautiful, in general, though some decorative metal can be an enhancement.
*I mostly agree with you Fred. The connectors need to be designed to handle all the stresses. Having A PE do this is a good idea.However...buildings have been built this way in alot of areas for a very long time. I'm afraid that if an engineer makes the cad drawings, faxes them to the machine shop where they are fabricated to within thousandths of an inch, polished, and x-rayed to make sure the welds are up to snuff, they won't be anything like what b. is looking for.I suspect the rough, hand forged, rustic look is what she wants. She (or he...no first name) needs a competent designer, maybe an engineer, who can understand that there are other ways to do things.Blacksmiths, carpenters, stone masons, riggers, and other smart people had successfully solved these problems centuries before any engineer even knew how to do finite element analysis.-Ryan BSME
*
Ryan:
I've quite a bit of experience in this sort of thing...no one is looking for overkill, x-rays of welds or a finite element analysis of the structure. A competent engineer will take Mr. Strube's plans and design, detail the connections and produce drawings for a modest fee. The engineers drawings are used in the fab shop to produce the connector, rustic or polished...thats the Owners call. BTW, Simpson does produce some heavy plate timber connectors and may even provide custom connectors.
And yes, carpenters, stonemasons, etc. solved these problems by
b trial and error
(errors resulting in catstrophic collapse)
...but we live in a modern world were we can calculate anticipated loads and design connections which are appropriate and make efficient use of structural materials. A rustic, hand crafted connector showing an artisans touch does not mean that the connector is any less engineered than one with more polished look.
*
Fred,
I re-read my message. I never intended it as an attack on engineers.
however, I know you would never claim that having something designed by an engineer is always the solution to preventing catstrophic collapse. That's why your liability insurance is so expensive.
I don't mean to trash engineering. There are many applications, especially in our modern minimilist approach to construction, where careful calculations must be done. Engineering allows structures to stand that look o the eye like they should have failed.
But, for most construction, in my opinion, an engineer isn't needed. I'm not suggesting that a DIY take on design, but an experienced contractor should be able to do most of the simple math and read the tables needed for most projects.
I'd never build a bridge without an engineer. I would trust an experienced timberframer to build a timberframe home without getting a stamp.
*
Ryan:
I didn't take your post as a personal attack on engineers...God knows that there are enough bad ones out there.....but even an experienced timber framer (at least one who has any common sense), would never utilize a steel framing connector unless it was pre-engineeered for its
b appropriate
application or engineered specifically by a licensed engineer. I know in our locality...any timber frame structure would require all member sizes, material specifications and connections (whether they be traditionally framed or steel connections) to be verified and stamped by a licensed PE. And, I would suspect, that most skilled competent timber framers keep a structural engineer on staff or as a sometimes consultant to verify and/or design those unusual conditions that arise in any custom work.
Finally, in response to the poster who questioned why one would use steel at all, steel can be quite elegant in its application and can make a striking statement aesthetically. Its all a matter of taste.
*
I did a little more searching on the WEB and did find one site that might help me:
METAL PLATE CONNECTED WOOD TRUSS HANDBOOK - SECOND EDITION: $39.95(member)/$44.95/$59.95 (non-member price)
http://www.woodtruss.com/wtca/wtcaindex.html
and click on
COMMENTARY FOR PERMANENT BRACING OF METAL PLATE CONNECTED WOOD
TRUSSES
I realize that for the house that I am designing that I will need approval from either an architect or a licensed engineer. However, I would like to do the preliminary design myself before I turn it over to the engineer, thus I would like the design criteria for metal plate connectors. Even if I were to have an engineer do the initial design I would want to double check the final results. I have known a number of engineers and architects and I can't say that I have known any that I feel are experts in this particular design area.
*
CaseyR:
I understand your need and desire to do your own design and try to save some $$ as well...I was in much the same boat 20+ years ago when I was living in Eugene...and I tried wading through design guides and finally realized that a certain prior knowledge of engineering principles was required in order to really understand what I was doing....it was then that I decided to bite the bullet and I enrolled in Oregon State University as a potential civil engineer...after being out of any type of school and pounding nails for a living...the 1st year was hell...but I began to realize that I was really as smart as some of these engineering whiz kids and also realized that it really was necessary to go to school for a
b minimum
of 4 years in order to have a firm grasp on the profession of engineering...I continued to graduate school in structural engineering because I still felt I needed more education in order to be a competent engineer (BTW, OSU has one of the finest undergradutae engineering programs in the country IMO...OSU grads kick a%% nationally (our grad class had the highest passing % in the
b nation
) on the EIT exam required of all grads who really want to pursue the practice and get their license.
My point being...do your own layout, spans, elevations, etc..try to get a feel for the approximate size of your members...but find a good engineer, and being in Oregon, you're likely to get an OSU grad, and pay them the money to do a complete design. If you provide the engineer with as complete plans as possible...you'll help save $$ by answering their questions beforehand...and you'll get a safe structure.
*
Mad Dog - a bit of an esthetic difference here, I guess that is what makes for variety in life - but the more I think about it, the more I like the idea of heavy steel reinforcing plates rather than standard joinery. Too much of the fancy joinery looks somewhat affected to my taste. I wouldn't mind really heavy beams with simple joinery, but I think that would take too much wood. I think the steel plates give the illusion of sturdiness with much smaller timbers required.
Fred - Okay, granted I will eventually need an engineer - so how do I go about finding one? I went through the engineering program at OSU, but in electrical rather than civil (way back in the days when we got lots of training in 3-phase power and other things that I never needed or used, and my best grades were in welding shop and analysis of structures...)
There is no one that I would consider up to the task here in my area of Eastern Oregon and I don't want to bug my architect acquantenances for references as they will probably try to talk me into using them for all the design and I don't want to do that. I also don't want to go for the "pig in a poke" of simply choosing someone out of the yellow pages.
I have spent most of my life as a college level educator, so what I hope to do is rough out the design, turn it over to some architecture students to give them some experience and see what they will do with it, and then have everything checked by a structural engineer to make sure everything will actually stand up to the wind-surfer strength winds in the Columbia Gorge and to our 6.8 magnitude earthquakes expected every 300 years or so...
*
CaseyR:
This is advice I would give very few in this forum...but if you truly went through OSU in EE, no matter how many years ago, you've got the mental tools to get yourself through the design
b if you've got the patience.
Get yourself a copy of
b Design of Wood Structures
(ISBN 0-07-007671-5), its probably been through several editions by now, by Donald E. Breyer, and the AITC (American Institute of Timber Construction), don't have an ISBN #,
b Manual of Design
...and wade through the design text and examples....its not cookbook...but you'll get the idea...and then do your own design, bring to a local engineer and have the design reviewed, signed, sealed.....chances are you'll do a more thorough design than you'd pay for, and a
b reputable
engineer will recognize the competence of your design and only charge for a cursory review and verification of numbers. But I only would recommend that route to someone, such as yourself, who had the benefit of a rigorous engineering curriculum (which OSU was...I went to NCSU for grad school and as a TA was appalled at what passed for academic effort, at OSU you
i earned
your degree). The engineering principles between basic EE circuit theory and building behavior are so similar it just always amazed me....kind of a common mathematical thread to the world...anyway, I digress...any local tech book store should stock either of those texts...call the good ol OSU bookstore and they'll ship them to you....
Good luck
fred
*
Fred,
you've won my respect. Few PE's would ever suggest that a non PE could handle some of the simple stuff.
*
Ryan:
I would never suggest that this is "simple stuff". Buying Breyer's book does not give one the equipment to design wood structures, timber frames, or steel connections...the book assumes one has a knowledge of basic engineering principles and
b the common sense to know how to apply them.
*
All right, you win, I take it back.
*LOL
*Hi Fred,I like you. Your allright for an engineer. I think were most of the other (other than you) Engineer types get in trouble is when they need the common sense thing. Seriously the ones I know are so lacking in this area that it's hilarious. One of em couldn't even figure out that studs need to be on 4' centers to catch sheet good seams.Anyway Casey I think that metal reinforcements make sense for the design loads that you must build for. Looking forward to seeing your designs.MD the lumber yards here within a mile or 2 of Casey stock units of 6 by 6or8,10,12,14,16 4 by 4 or,6,8,10,12, all in lengths to 8-20'. This is all Doug Fir and some of it pretty good stock still.joe d
*
joe d:
unfortunately you are correct that many (perhaps most) engineers are lacking in the common sense arena. Personally I feel that prospective engineers should spend an apprenticeship in their chosen field prior to study to give them an apppreciation for the havoc their unrealistic designs cause in the real world. I once had an engineer insist that he needed 54 1" dia. anchor bolts to anchor a 2' dia. steel tube section to its foundation....because thats what his calculator told him....or the time in Reinforced Concrete Design (after 1 month of lectures), a student asked what this rebar stuff was....its sad...but the good engineers are out there...finding them is the trick.
*
I would like to use an exposed timber frame with steel connectors and lateral bracing. Does anyone know of someone making steel bolt and plate connectors for this type of construction. The design of these connectors and bracing needs to be pleasing to the eye, not simply a Simpson joist hanger for example. thanks in advance