Now I have placed this on the Homesteading Sub-Forum, only because it did not fit the other sub-forums in Building so readily. But there are basically two ways of approaching a “green” barn. (1) Using untraditional building materials (2) Or, using a unique design to drastically reduces conventional materials. Without apology; the barns I build are of this latter design concept.
In a nut shell, they use 1/3 less of the traditional framing lumber because they are posted 4 feet on center instead of 16 inches on center, yet use the same 2 x 6 and 2 x 4 dimension lumber. This adds up to significant savings. To carry the loads imposed, they are constructed as trusses, but not in the usual way, instead they are rather a cross between timber framing and stick built construction. I typically build the walls out of 2 x 4’s, the rafters out of 2 x 6’s and all the braces out of 2 x 4’s as well. This is not only to make the weight of the trusses lighter, but also reduce the number of lumber required to build the same size barn.
The truss dictates the shape of the barn, because it incorporates the wall framing and rafters as one cohesive unit, like how bents are raised on timber frame construction, only they are 1-1/2” inches wide instead of 8 inches. Like timber frame bents, the parts are all cut on the ground with the bents built on the ground. To connect the walls to the rafters, bracing and whatnot that makes up an individual bent, plywood gussets are used. Now ONLY engineered wood can be used for gussets because if they are made out of solid wood, they will split when nailed or stressed. I have used OSB (Oriented Strand Board, also called chip board), but I don’t recommend it because it is prone to moisture issues, ½ plywood is best, and honestly a few sheets of it goes a VERY long ways. That is because it only takes (2) gussets, 3 x 8 inches to make most solid connections. The strength of the joint comes from the layers of the plywood and the nails. Never skimp on nails for this reason. Where 4 will work, I put in 8.
It does take a little bit of confidence to construct a barn this way, because I might spend a whole day just cutting rafters, studs, bracing and gussets to various lengths. This is NOT a cut, check the fit, cut another, check the fit sort of construction. You lay out the first bent, get all your patterns, count up how many parts of each you need, and cut them out. Then you nail it all together, gussets on each side of the joints.
When you get a bent together it will scare you, they are designed to carry compression loads, not side loads so they are very floppy. This is because you can make some rather large bents since you are just flipping them up into place. Bracing the first bent is the hardest proposition, but as each bent goes up, it gets easier. Purlings laid across the top of the rafters, and in between the “bays” , whalers stiffen the building as it is being built. Time wise though, this is very fast construction because everything has been built on the ground. You need to just tie everything together as you stand the bents upright. Working in 4 foot increments, it goes fast! My father (67), my wife (35 and weighing 130 pounds mind you) and myself (40) were able to frame my last 30 by 48 foot barn in half a day. It took me one day previous to cut all the bent parts and assemble them, but 1-1/2 days for a barn that size is fast. I used a nail gun, but it is not required, you can do everything by hand.
Other than plywood gussets, the only other requirement is a steel roof. It has to shed snow due to its four foot spacing. At $1.99 for 3 square feet, it is very cheap roofing material though. Just place the steel on the purlings and screw it down with steel roofing screws. Most of my roofs are 6/12 in pitch, but due to an already existing building, my last barn had a much lower roof pitch. I just merely needed to add more bracing to reduce the load on the roof should we get a lot of heavy snow. I am NOT shoveling off the roof of that barn…no way.
Is this design a disaster waiting to happen?
This is a design taken from chicken barns built in the 1960’s all around me and are still standing. These were 3 floor, 400 foot long buildings too. The oldest barn of this design on my farm is 30 years old and is still standing. I have a total of 4 built like this and all are standing and sound.
The key is to get the snow load off the roof, but also think of terms of stress. “If I step on the roof here, where does my weight get transferred too? What would have to fail for this to collapse? Thinking that way, through bracing you can reduce spans and fortify weak points. Short sections of bracing cut 2 feet long with 45 degree cuts on each end stiffen the bent tremendously just as they do on timber framing bents. The steel roofing tightens things up as well.
Is this design okay for human living?
Yes and No. This is not because it is not structurally sound, but rather because the 4 foot spacing makes it hard to insulate and hang sheetrock. I was able to add strapping (1 x 3 inch boards) on my insulated lambing pen, but it was almost harder than it was worth. Just adding a bent every 2 feet would have been easier and thus make insulation and drywall easier to put up. On a living home, I would just go with 2 foot spacing instead of 4. Same method of construction, just more bents.
Is this a beautiful barn?
Gracious no! I would love to have a timber frame barn and admire those that have them, but in Maine where I need a way to house my sheep, yet do so cheaply because of the thin financial margins of sheep farming, this style of barn works well. Perhaps in my next life, or down the road, I’ll build the ultimate barn.
Now a few caveats. Where I live we have no building codes or code enforcement officers that inspect the premises. As long as I purchase a $25 building permit, I can build whatever I want. This may, or may not be the case where you live. Generally outbuildings are less restrictive, but not always. Any building funded by the NRCS or FSA must be engineered by a licensed structural engineer. Another thing is the price. It is low because I have plenty of logs to convert into rough sawn lumber. Even then, I have to purchase a few sheets of plywood. It can be built with lumber from a lumber supply store, it will just cost more.
Pictures are worth a thousand words however, so you can judge for yourself.
Travis Johnson wrote:
The key is to get the snow load off the roof, but also think of terms of stress. “If I step on the roof here, where does my weight get transferred too? What would have to fail for this to collapse?
How do you get the snow load off of that roof? I was imagining you were going with a fairly steep pitch but that doesn't seem to be steep enough to shed snow.
I am not sure if you can tell in the photos, but I was under some tight constraints with this one. The concrete was already there so it made sense to add on to the shop with a new roof line. The problem was, being 30 feet out, then being high enough to clean out the barn with my tractor, it made for a low pitched roof. You can even see in the photos that the second bay is really short, 6 feet tall. It is all I can do to squeeze by bulldozer in there to clean out, but I can, I just have to duck my head for the light bulbs! It would have been nice to have another foot of headroom, but if I had done that, I would have had a really low pitched roof. It worked out, but barely!
I would NEVER recommend a pitch this shallow that is for sure. I pull it off here in two ways. Part is the micro-climate. The long sloped roof faces the North and prevailing winds. I am also at the top of a big hill (I can see some 175 miles away) so this place gets slammed with wind. Typically the snow loads are low because it blows off this roof. In 2 foot storms with wet heavy snow, I fret, but it is braced really good. It has 7 load bearing points on that 52 feet of rafter, so the longest rafter span is only 8 feet.
We do like this barn though. We have had it up for two years now and the through-barn feature is nice. Two passes with the bulldozer and the floors are clean. The fold up managers have worked flawlessly and being draft-free below 4 feet, but wide open above, makes for healthy sheep. We had a sheep di a few weeks ago so the State Vet and I cut her open and her lungs were gorgeous. When I asked why, he pointed to the barn, "wide open barn". There is no manure smell build up so no pneumonia. By closing it in anyone can use it for something else, but this is designed and works perfect for sheep.
BTW: The gates inside the barn act as a covered sorting chute, foot bath and shearing room. That is important because uncovered chutes 4 feet high with 3 feet of snow in them do not work.
I was curious - any chance you might be able to put a picture up of the 'floorplan' for these buildings? I loved the detail but if you've got a quick sketch it'd round out your lovely post.
Marisol Dunham wrote:I was curious - any chance you might be able to put a picture up of the 'floorplan' for these buildings? I loved the detail but if you've got a quick sketch it'd round out your lovely post.
Let me see what I can do. This is harder than you realize, only because I am very old school. So old school in fact I don't even have a cell phone. I don't mean a smart phone, I don't even have a flip up phone or anything! In any case, I love mechanical drawing and that is what I typically do for doodling up what I intend to build. But the Commissioner of Agriculture here in Maine challenged us to "share our knowledge" and I have really tried to do that this year.
I hope I do not sound too conceited when I say this, but while the design is really efficient, the floor plan has proven to be even better. The older portions are many years old, and the new barn is two years old, so when I say that, it is time tested. I also want to share this because it houses a variety of animals. Straight up, we are a commercial sheep farm and that is what we do, but we have a few other animals that we house for our own use; ducks, chickens and a beef cow.
The cow has a 3 sided lean too off the chicken coop that is 8 x 12 feet in size. This has concrete floors, lights and outlets.
Beside that is a 8 x 12 foot chicken/duck coop that is insulated, heated via geothermal, with a wall inside the outer wall by four feet. This wall is lined with chicken wire so that there is a double door system. With springs on both doors, it is impossible for the kids to leave the doors open and let the ducks/chickens out. In the summer when they free range, but nest back in the coop at night, latches on the door keep them propped open. The 8 x 4 foot area inside, but off limits to the ducks is our "grain room". This is where we keep metal trash cans for the chicken grain. It also houses a shelf where we keep our egg crates stacked. It also has a traffic cone fabricated to the wall upside down, our method of butchering birds (the bird is placed upside down in the traffic cone, sticking their heads through the tiny part, where...well you know). Overhead of the chicken coop is a storage area, accessed by built in ladder in the grain room. Naturally this grain room/coop has lights, outlets, a concrete floor as well with an insulated door from the outside.
The next area is a 12 x 24 insulated lambing pen. This room is split into two parts. On one wall next to the chicken coop is (5) 4 x 6 feet lambing pens. These are boxed in 4 feet high with outlets above every pen for heating pads to warm the lambs. Each pen has a manager for hay and water buckets. These are only used for a day or two for Ewes and their day old lambs. The majority of the area is open. That is to allow ewes and newborn lambs over 1 day up to a week or two, co-mingle with other lambs and ewes, yet not be out in the main barn. This area has a concrete floor, and two doors. The first is a big door that allows a farm tractor to clean out the bigger open area. To clean out the lambing pens it is shoveled out to the main part where it is scooped out. The second door is towards the front and leads to the main barn. The barn is insulated, along with both doors, but not heated. The body heat from sheep keep this super-insulated lambing barn from freezing even at below zero (f) weather. This is also where shearing takes place.
There is an 18 inch elevation change from the lambing barn to the main barn, there is also a 7 foot by 24 foot area broken into (6) four foot sections. The first 4 x 6 foot section has a man door to the outside so we can enter the lambing barn to tend animals, or slip thrrough a latched gate into the main barn. This area has concrete, but is also sloped. In the floor is a foot bath with a trap door so it can be ramp, or a foot bath too. Because of its position, it allows the entire flock of sheep to be run through the hour glassed area. This area also houses a fire extinguisher and our chalk board for writing down sheep numbers we are having issues with. The area also contains a ladder going up to a 7 x 24 foot hay loft over this area of the barn. I is used for storage and for a kids fort. Long stuff can be placed up there via a hayloft door on the outside of the barn. This area is well lit, has its own outlet and even a 220 outlet for my welder.
The next bay over contains our tools, everything from hoof trimming tools to fencing tools, to towels to dry off newborn lambs. It has a table and hutch, and plenty of pegs to hang barn cleaning tools. It is just a 4 x 6 storage spot. The next four 4 x 6 stalls we call our "medical pens". These are where sick sheep go and so the individual stalls have lights overhead and their own outlets for heating pads, heat lamps or additional lighting. Every bay here, all 6, have latched gates. This area is not quite done, I still need to pour concrete on the floors and board in the individual pens, but I am a busy guy!
Our main barn is a through barn meaning to clean out, we simple push the manure from one end of the barn right out the back to the other. Our barn is further split down the middle by the "half wall". With gates at each end in this half wall, the barn acts like a sorting chute. We used steel tube gates with steel roofing screwed to the gates at the ends. This gives our end gates a draft-proof setting when our lambs are born in winter as we winter lamb, but the gates in the middle are just for extra sorting. It all depends on where we are in lambing. We might enclose 1/4 of the barn for ewes and nursing lambs who would be crushed in "general population" as we call it, or we might pen in dry ewes. The point is, we never chase sheep. Typically we let the sheep from one side of the barn (a 12 foot alley) through a half wall gate so all our sheep are contained in one half of the barn. Then we clean out, fill the livestock tank with water, then fill their flip out managers. Then we let the sheep back in and clean out the other side. With steel roofing along the walls, and a concrete floor, the manure easily pushes out.
As for outside lights, goodness gracious we have them. Front, back, sides; I guess I must be afraid of the dark because our barnyard is about 3-1/2 acres in size, and when we flip every outside light on, there is not a shadow to be found in those 3 acres.
So yes it works quite well. It is geared towards sheep farming obviously, but ultimately I think we properly house our animals. I feel good in doing that.