We are building a barn and trying to match the architecture of the original buildings on our property. The photo shows the original roof trusses, which are built from 3 layers of 1X4 pine bent and nailed together to form the arch. I was told that they achieved the bend by soaking the wood in the river, then bending them in a jig. This sounds too easy- seems like everything I read about bending wood says you must steam heat the material to make it work. Since the farmers didn’t have steam chambers 70 years ago, they must’ve done it without…will this work?
This building is about 17 feet wide, and the trusses are about 13 feet along the arc. As you can see by the photo, the bend radius gets fairly sharp about midway up the arch.
Replies
It wouldn't take much to bend a 1x on that axis. Attaching the 3 pieces together in a jig and allowing them to dry before removing them would probably make them hold their shape.
That looks really cool. I wanna try that on something.
View Image
A qounset hut would look cool in yer front yard.Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
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http://www.youtube.com/watch?v=Dj_oEx4-Mc4
The world of people goes up and
down and people go up and down with
their world; warriors have no business
following the ups and downs of their
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with a copper roof on it.View Image
BTW, Here's what I plan to put them in...sorry, the roof isn't copper.
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Shawn
Edited 10/15/2008 8:58 am ET by shawncal
Edited 10/15/2008 9:00 am ET by shawncal
Edited 10/15/2008 9:00 am ET by shawncal
SWEET BARN!
One of my biggest regrets is that the barn on my grandparents homestead (built before the turn of the last century) is beyond repair now. Grandpa cut out some structural ties to get the combine in back in the 60's, and after he passed, grandma did not want to take the expense of stabilizing it away from the estate. She lived to be in her mid 90's and by then it was past the point of rescue. We are just waiting for it to fall in on itself, there's no really unique lumber or anyone who wants to get that high up to tear it down. Really sad, it was a majestic old structure in its day.
Those old barns,motise and tenion, with pegs, are incredible with their ability
to hold together. I have tried to demolish some, but the only way to take them
apart is to do just that. Take the barn apart piece by piece. That being said ,
I don't know the conditin of your parents barn,but you might retink saving it.
larry b
really wish we could save it, but since the ties Grandpa cut out were structural, and combined with sill deterioration (the sand blew up against and the bugs went to work) it is beyond hope. Too much twisting and collapse already to be reversed. This is in south central Kansas and the great ones still standing are few and far between already. Really sad.
Maybe you could have a "barn saving fest".You get out of life what you put into it......minus taxes.
Marv
Steam gets the moisture into the wood faster thats all. A stream should work too. I would use a modern glue to bond the pieces together. You can add nails for the look.
You get out of life what you put into it......minus taxes.
Marv
Barns with that style roof are fairly common here.
IIRC there was a plan sold or given out by one of the govt. farm agencies that detailed construction techniques for them.
The one design of that style I actually helped build in the early 70's we didn't steam or soak the lumber at all, simply laid down a jig on the floor and dry bent the 1x around it. Used D.F. 1x though instead of Pine.
There was a really good article in Mother Earth News about 25 years ago about the construction of a Gothic Arch barn. They used 7 pieces of 1x material to build each rib, and they built the jig on the floor of the barn. I saved the article; I'll see if I can lay my hands on it. It was really fascinating.
Greg
Sweet Barn! Looks like something that you might be able to learn about in a series of books called "Foxfire" Your local library might have them. Amazing source of old how-to stuff. Good luck
We did a structural investigation of an arch similar for an arena structure (just a bit bigger). After discussing with the old timers we found that they harvested the wood locally, milled into 1" stock, air dried, and field nailed (by hand) them into arches. We x-rayed the arches to determine the size and number of nails. That would have been a lot of 3" nails to hammer by hand. Ahh, how life has changed.
Brad
Okay ! I found it ! Tha article was called, "A Smoky Mountain Barn Raising" Mother Earth News, March/April 1982. I don't have a scanner at work - it's a really good article - if anyone here will provide a fax number, and the original poster, too. Maybe someone could scan it and post it.
This was a large barn, 40' x 80', and the arched roof was three stories to the peak. I was right about 7 layers, but they used 3/4" x 3" material.
Greg
Here's the scanned article. First 2 files are print quality 8 1/2" x 11" Second set is screen quality (for those who don't have broadband yet).
Enjoy!"It depends on the situation..."
Thank you so much for posting this, Jason. I knew there had to be a reason for me to hold onto that article for over 25 years ! ! I was intrigued then, and I still am. I spent some time in Eastern Pennsylvania as a kid, and the beautiful bank barns there in Amish country were amazing.
Thanks again !
Greg
With all those ribs it's kind of like building a really big boat, isn't it? I've heard this kind of barn referred to as a "Wisconsin style", but that may just be a local name.
There's a state park in Wisconsin where they have moved 67 historic 19th and early 20th century buildings into one park. At the entrance there is an 8 sided barn they have turned into a nice restaurant.
As you move around the park there is a Polish farm, German farm, Chec farm, etc.
As you walk onto a farmstead there are several buildings along with the barn with docents (volunteers) dressed in period dress that tell the story of the farm and the people.
My wife and I did a special event around Christmas where a docent leads you around with an oil lamp. You visit farms, sing carols, and then have a nice authentic German meal. I highly recommend it.
They also do a great 4th of July celebration complete, a greased pole with a $20 dollar piece on top, pig chasing, parades, and with opposing political candidates giving speeches. They don't come to blows but definitely speak their minds. Our current politics are tame in comparison. Can you tell I miss Wisconsin?
http://oldworldwisconsin.wisconsinhistory.org/
Edited 10/21/2008 12:04 am ET by popawheelie
lindenboy, GregGibson, and I'll throw in draftingguy too, thanks for scans of the construction details! Now THATS how to have fun in construction! (Aside from immediate payment of invoices :} ).
I'm an Architect and I've got to get a client to want one of those. Thing is the buildings are quite adaptable for any number of uses. Granted there aren't a lot of carriage collectors but there are antique, vintage car collectors who would kill to have an environment like that to show their cars or whatever.
Got to get on with my reading!ciao, ted "You can have it fast, good or cheap. You can only have two of the three. Fast and good, it won't be cheap. Good and cheap, it won't be fast. Fast and cheap, it won't be good. Now, what's your choice?"
Still available on the web.http://www.motherearthnews.com/Nature-Community/1982-03-01/Building-A-Barn.aspx?page=1
Edited 10/21/2008 3:52 pm ET by Dam_inspector
Wow, the man just joined us, and he's matched my 25 year old filing cabinet ! ! The whole Dam article from the Dam inspector ! Good work !
Hey, fill out your profile, so we can get to know you . . . and WELCOME to Breaktime ! Just click on your name, above, in blue, and tell us about yourself. It's always good to know what part of the country a poster is from.
Greg
In case no one else has already posted the link:
http://www.motherearthnews.com/Nature-Community/1982-03-01/Building-A-Barn.aspx
They keep most of those old articles online.
jt8
Edited 10/20/2008 4:17 pm by JohnT8
You might want to buy lumber locally that has not been kiln dried. Ash would be my first choice. I would guess at that radius, you would not need to soak it at all. you are correct on using a form to bend the multiple layers.
Here's a link to a drawing like the one I believe Dovetail was talking about:
http://www.ag.ndsu.nodak.edu/abeng/plans/5220.pdf
The main construction plan page has some other interesting plans that would be fun to try:
http://www.ag.ndsu.nodak.edu/abeng/constructionplans.htm
draftingguy, thanks for the links! I'm always looking for interesting resources that may be adaptable to projects. I can see that I'll be doing some reading for a while.
BTW do you work on the board? Years ago my busines cards identified me as a "Draughtsman", the old style spelling. Oh, Architect here.
Thanks again. ciao, ted "You can have it fast, good or cheap. You can only have two of the three. Fast and good, it won't be cheap. Good and cheap, it won't be fast. Fast and cheap, it won't be good. Now, what's your choice?"
Yeah, that's part of my work. Unfortunately I don't often get a chance to do any work by hand. I assume that if your cards read "draughtsman," you actually put pencil to paper.
I've been trying to figure out a way of using some of these old agricultural plans. We'll see if I'm ever able to.
....."you actually put pencil to paper."Yep, and I still do. With the growing need for CAD programs I'm slowing converting over but a majority of my work is 'on the board'. I've had a couple of clients honor my work by framing particular drawings they like.
You got me to thinking how interesting it would be to frame those old agricultural plans as well. Now those guys could draw! I have a small collection of old prints. The white line on dark blue background type. Worked for one firm that did all their work on the Irish linen 'paper', in ink no less. Absolutely amazing skills.
Take care. Still reading. ciao, ted
"You can have it fast, good or cheap. You can only have two of the three. Fast and good, it won't be cheap. Good and cheap, it won't be fast. Fast and cheap, it won't be good. Now, what's your choice?"
One thing you might want to do is do a test piece first. One thing I've read is that there usually is whats called "spring back". So if you want a certain bend in it you bend it further and it will spring back to where you want it.
just a note to let you know they were steam bending wood a lot longer than 70 years ago. my store now sets where they steam bent buggy wheels and such. back in the early 1800's and we have pictures of it the old timers did some very interesting things
I think Ken Kern wrote about making rafters like that in one of his books. The rafters were built in a jig on the the deck.
(KK wrote The Owner-Built Home, The Owner-Built Homestead, and The Owner-Builder And The Code, all three good books that are currently hard to find.)
I agree with popawheelie that you might get some springback. You'll know as soon as you pop that first rafter out of the jig. Screws for the first one, then? Also, the more laminae, the less springback.
Two kinds of jigs: Form blocks on the inside of the curve, and form blocks on the outside of the curve.
Easier to wrap around inside blocks, but you have to screw, and later unscrew, the jig blocks to/from the first board. Use clamps as you work your way along -- its easy to end up with little gaps that make for more springback.
Form blocks on the outside can make for tighter laminations because you can use wedges (or some kind of thrust clamp) at the ends of the boards to press the laminae tight. Which means less springback. And you don't have to unscrew the rafter from the form when you're done. One drawback is that you really have to fasten the form blocks securely to the deck to resist the thrust force. You still need to clamp your way along, and keep going back to tighten the wedges as you go.
Either way, remember to nail back through the first board(s) after the rafter is thick enough to receive the full length of the nails.
And give daily thanks to Pneumos, the god of air-nailers!
AitchKay
Edited 10/16/2008 9:13 am ET by AitchKay
Make a really sturdy jig and soak* green lumber overnight. It will bend like a wet noodle..
Don't attempt this with wood from a lumberyard!
Find a sawmill and have them saw you fresh,green wood Knot free is best but as long as the knots are solid and not really big they won't bother you. .. Don't worry pine, ash, elm, anything will work. Get what is cheap.. (white oak will cause nails to rot so don't use it or black walnut)
The boards too can come from a sawmill (you'll find they are considerably cheaper than lumberyard wood)
Don't have anything that long? don't worry.. dig a trench, line it with seamless plastic (another words don't try to tape tow pieces together), set the wood in place, hold it down and then fill with water. Once you're done pull out the plastic and fill back in the trench!.
*soak as in under water,, you have to weight it down or hold it down somehow..
original roof trusses, which are built from 3 layers of 1X4 pine bent and nailed together to form the arch. I was told that they achieved the bend by soaking the wood in the river, then bending them in a jig. This sounds too easy- seems like everything I read about bending wood says you must steam heat the material to make it work.
A local nursery here builds all their temporary greenhouse frames that way. It's dry bending; you simply take green 1x and force it into a curved jig screwed to a wood deck, one piece after the other. For the greenhouses--which are considered fairly disposable--they simply air-nail with 2½" x 16-ga finishers through and through then clench the nails over that poke through.
For your application, I'd suggest you laminate the ribs with a structural epoxy or PU glue, using air-nails or screws and lots of clamps. Once the glue dries, you shouldn't get much springback and what little you get you can re-bend to spec by hand when you install the ribs in the structure.
BTW, for bending wood beyond its 'dry-bend' radius, heat is the important element, not moisture. Steam is most often used because it's an easy way to heat the wood without damaging it, but wood can be bent by first baking it in an oven or heating it with a torch or placing it in a fire until it is hot enough, and then the charred exterior planed/scraped off after it has cooled.
The heat softens the resins which bind the individual wood fibres together and allows them to slide longitudinally in relation to each other. Soaking the wood in cold water has no effect on the resin--it's not water-soluble--other than to harden it up and actually make bending more difficult.
Green wood bends more easily and sharply than seasoned wood because there is still cellular water inside the wood fibres.
Dinosaur
How now, Mighty Sauron, that thou art not brought
low by this? For thine evil pales before that which
foolish men call Justice....
Dinosaur,
The key word that caught my attention was your reference to wood's "dry bend" radius- is there information somewhere that would tell me what can be achieved for a given species/size? That would help me determine what is possible, since I'd rather not mess with heating or water.
thanks to all the great info on this thread, everyone!Shawn
Go to the lumberyard, grab a board off the stack, and start bending. It's as simple as that.This talk of soaking and steaming sounds like the original builders in a bar after the raising, trying to impress ignorant rubes.Last Fall I used a sprung 1x6 to help lay out a curved retaining wall. I didn't measure, but I'm pretty sure I bent a 16-footer 2' out of straight, and I wasn't going for the max, just for the curve I wanted. I drilled a hole in each end of the board, ran a length of rope through the holes, and cinched it up with a tautline hitch (two turns inside the bight, and one turn outside, all in the same direction, for those of you who don't know the knot).Don't over-think this stuff. Buy that board, and take note of how far out of straight it was bent before it broke. If you still aren't sure, buy a couple more boards, and break them, too. 'Nuff said.AitchKay
wood's "dry bend" radius- is there information somewhere that would tell me what can be achieved for a given species/size? That would help me determine what is possible, since I'd rather not mess with heating or water.
'Cold bending' would actually be a better term than 'dry bending,' but there you are. People are horribly sloppy about terminology....
There are a number of factors which control how much you can bend a given thickness and species of wood. One of them as I mentioned is how much cellular water remains in the wood; another is whether or not a bending strap is used. When attempting to bend wood to small radii, a steel band or strap is clamped to the outside of the piece to be bent. This prevents the fibres on the outside from being stretched beyond their breaking point and in consequence compresses the fibres on the inside of the arc. You can put a much sharper bend into a timber with a strap than without one.
There may very well be charts out there for the standard wood species; I don't know of any personally as I do very little work of that sort anymore. I'd suggest you run a Google search for 'wood bending'.
But all that's probably academic in your case. From what I saw in your photo, I seriously doubt you'll have any trouble dry-bending green 1x stock to the radius you need. If you pick up a 16' piece of 1x3 at one end, it bends almost that much under its own weight.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
Shawn
I am not an expert wood bender, but a 1x4 that is soaked for a few days will flex better than if not soaked.
Then when laminated to another one, they should lock together very close to the position that they are jigged to.
Heck, give er a try if you still have the stream!
I would probably screw and glue the laminates and you might want to go thicker than origonal unless you engineer it. The old wood is probably a better grade than what you can buy today.