How to fasten dimensional lumber rafters to round timber ridge beam.

Hello to all.  I am building a pole-barn style sheep house in northern Maine.  The house is 24' wide and 60' long.  In the attached photo, the posts are seen in place.  The posts running down the center rise 10' above grade; the sidewall posts rise 6'.  (There will be 11 posts in each row- 6' on center.  Each end of the house will be open so that I might scrape out the house with a compact tractor.  The sides will be walled up only half-way for ventilation.  The roof is slated to be metal.  I am now at the point where I have to level off the tops of the posts and place the three 60' ridge beams.  I have decided to use round timbers for these beams because I have a woodlot with spruce trees and my budget for purchasing dimensional lumber is extremely limited.  The ridge beams will be hoisted up using a friend's excavator and pinned to the posts with 1/2" rebar.  My plan is to then use my limited cash for sixty 2" x 6" x 16' rafters placed 24" on center.  And so a question arises: how to fasten the dimensional lumber rafters to the round-timber ridge-beam and round-timber 'wall plates' of the sidewalls.  Yes, I have seen the photos of beautifully notched round timber beams for dimensional rafters.  For various reasons, I would like to not have to do such woodwork.  (I am not an accomplished woodworker; I would like to save the time needed for such notches; and I do not have the kind of scaffolding or staging that might be necessary to do such fastening.  I am wondering whether there are other, easier, ways to set the rafters.  For example, perhaps I will bolt them together (side by side) above the ridge-beam such that they rest on the ridge-beam, and for the wall-plate beam I will do some kind of bird's mouth notch.  I have spent time researching this question but cannot find a solution that does not involve the fancy notching of the beams.  Also, I am working alone.  I could, if really necessary, hire a helper.  I would really appreciate any ideas from anyone who might have done this kind of project.  Edit: I will also be installing collar ties and rafter ties.

The easiest way is to just buy 60 linear feet of 2x8's for your ridgepole. If you really want to save money, just use 1x8 boards. I know you said have little money to buy lumber, but cjeck out Uncle henry's for Rough Hemlock Framing Lumber. It would be very little money, well spent to save a lot of work.

Keep in mind, the ridgepole does not require strength. The strength of the building is gotten from how the tops of the rafters wedge on top of each other. Back in the old days, a ridgepole was often made of simple boards because it is not weight-bearing. You will need to provide collar ties at the eveline so that a triangle is formed, but that is pretty common knowledge, and has to be in any building; trussed, timber framed, or raftered.

I actually typed out a long reply on how to easily, and quickly square up logs by hand, but then realized it would have been wayyyyyyy overkill as a ridgepole does not need to be beefy at all.

I did save that reply in case you want that information...you know, from one Maine Sheep Farmer to another. :-) Best of luck on your sheep barn!

Travis Johnson wrote:Keep in mind, the ridgepole does not require strength. The strength of the building is gotten from how the tops of the rafters wedge on top of each other. Back in the old days, a ridgepole was often made of simple boards because it is not weight-bearing.

Travis, Thank you for your reply.  My main concern for the sheep house is snow load.  My posts are white cedar- not the strongest wood structurally, so I used 11" diameter posts.  It was my thinking that I should use equally massive poles for the ridge beam and wall-plate-beams.  My rafters will only be 2" x 6".  Do I understand correctly from you that there is no benefit to be gained by a heavy ridge beam and wall plate? That I should simply put a 2" x 8" on edge on top of my posts and mount the rafters in the usual fashion?  Note that poles do not cost me money since I have the wood lot, while every board that I buy hurts my small pocket, lol.   I appreciate your time and attention.

Since you have a wood lot and I assume young conifer trees growing there, I would harvest rafter poles from the woodlot and save your money on the 2X6 purchase. You can also harvest the same for purlins. Your roof sheeting (metal or wood) can be affixed directly and you traditionally join the poles to your ridge (if you're still going to use a timber ridge).

I never cared for pole construction because there is no flat point to measure from. It really makes it hard to build when there is no reference point. So if you do not want to buy some dimension lumber, my suggestion would be to square the (3) long ridge pole timbers, but please hear me out before you begin groaning! :-)

You do not need woodworking skills to do this, nor have to have fancy tools, or take a lot of your time. I think you could just square up just the two outside faces that the rafters attach too, but making a 4 or 3 square beam would not be that hard either. Now I say all this with experience, having done this for my timber framed home. Time wise, I was doing 12 foot, 8x8 beams, four sided in 1-1/2 hours. That equates to 7.6 minutes to make a linear foot of 4 sided square beam. Assuming you would get that rate of production or better (conceivably twice as productive you only square two sides), a full day of squaring up timber work, would get you what you need. Honestly, I think spending 8 hours making a squared ridge pole on at least two sides, will make up a lot of time when you install the rafters to the ridgepole.

Somewhere I have a picture of me doing this, but I have not been able to find it on my computer for years. Still, all I used was a tape measure, crayons, a rafter squares, a short level, a chalkline, a regular ole axe, a hammer, and a chainsaw. I also had two saw horses to put the logs on so I was not bending over.

I started by finding the center of each end of the log. Then measuring 4 inches from each side of that, that made a 8 inch square centerd on the log. Then I did the same thing on the other end. Then I took a chalkline, and using nails to hold the end of it (as I work alone too), I laid out the longitudinal lines on the log.

From there, I used my chainsaw and CAREFULL cut down to the lines on each side of the log. I made these cuts every 8 inches. I found this was the ideal spacing so that a I laid my axe flatways to remove the chunk of slab on the log, it would break without too much pounding with the hammer. Naturally this will leave you with a log that is flat on one side. Now just flip the log over and do the opposing side. This will leave you with a log that has two flat sides. Just keep going for (3) sides, or (4) sides...a square beam if you want. (3) 20 foot beams will give you 60 feet of 8x8 ridgepole. Overkill, but they would be free (save a tiny bit of chainsaw gas and bar oil).

The only real caution is, do not make your chainsaw cuts too deep...just go to the lines.

For beams for my house, the look was too rough for me, so I used a hand electric power plane, and smoothed up the beams. That is not required though.

Dan, thank you for responding.  Yes, I did initially plan to do as you have suggested.  My problem was that I figured that I cannot put up a purlin to support round timber rafters.  My sheep house is about 24' wide- 12' wide on either side of my center posts.  What with the 60' length of the house, I think I would need, at the least, one purlin per side, and then some two or three or even four support posts for those purlins; said posts would prevent me running through the house with my tractor for cleaning.  I hate to have to be buying my rafters, but it seems to be the only way to make do without purlins and handle the snow load on a structure that must permit a tractor to run through.  (The Kubota B5200 is say, 4' wide and a blade would be about 5-6' wide, so maybe I could, actually, steal some width for support posts, but they could not be centered under the rafters.  Do you get what I mean?)  I have acres of wood and could easily find candidates for purlins and rafters.  Frustrating.  If you can think of a solution, I would be eternally grateful!   As it is, I am hoping I can get away with using 2x6s for the 16' rafters.  2x8s are somewhat pricier.  {Just to recap for your consideration:  Center posts are 11" dia., 10' high, placed every six feet; side posts are 11" dia., 6' high, placed every six feet; and the width is 24' or 12' either side of the center posts.  The ridge beam and sidewall top plates will be round timber, 8" dia., 60' long.  I think the roof slope is thus 5:12.}   Thank you, Dan.

Travis, that is beautiful work you did there!   Yes, I thought about squaring or giving the beams flats.  And I believe that I could do them pretty much as you described.  But I have the idea that I simply let the rafters sit on the ridge beam, i.e., they go up past the beam a bit and are bolted together.  It is called scissoring.  I understand it is code, too.  But I am still deciding...

Yeah, you could do it that way too. You could even cut the rafters at an angle (disect the angle) with the round, ridgepole laying underneath it for support: scissoring if I understand it right. IF the ridgepole roundness got in the way, just trim the wood off with a chainsaw, I mean you are only shaving off 1-1/2 of wood-width where the rafters hit.

I am surprised that Linneous has building codes, just because even where I live they are unheard of. Some person from away wanted to pass a rule where a house had to have so many Smoke Detectors per square footage of home, but they almost got tarred and feathered for that suggestion. We have a lot of Amish here, and since they will not have smoke detectors in their homes, a few of us went to their defense pretty quick. They are good neighbors, why try and pass rules that make them upset?

But I will say, I do like your overall design. Your sheep barn is a bit longer than mine, but mine is 24 feet wide, with (2) 12 foot bays. It is also a through-barn design to make cleanout easy. I have concrete in mine so I can push a HUGE amount of manure out the door with my little tractor. I am not telling you how to build your barn, but on the inside, I lined the walls with steel siding. It was only 1 sheet high (3 feet), but allows the manure to slide without hanging up on the walls, and keeps drafts from getting on my lambs. The barn design alone allowed my mortality rate in lambs to drop by almost 10%. In fact, I think since building my barn in 2015, I have only lost 2-3 lambs due to "exposure", and I winter lamb too.

Another thing I did, was install (2) gates on the center wall. This is nice because I can run my sheep around in a circle, or from side to side without the end gates to the barn being opened. When I clean out, I run the sheep to one side through the gates, then clean out half the barn...the side that is open, then I shuffle them back, and clean out the other side. I also put gates halfway down my barn so I can divide my barn into (4) sizable pens, (2) pens on each side. Your barn is long enough so you could have (2) sets of gates and have (6) sizable pens (24x20 pens).

My barn also has fold out hay racks. I built mine out of 2x4's, but they fold out when we want to use them to hold hay, but fold back against the wall when I am cleaning out with the tractor. These are just some desihn ideas that worked for us. Naturally you can do whatever you want.

Here is the gates in the center wall. We call our center wall, a "Half wall" because of how we used the steel to allow easy manure cleanout. Unfortunately, the only picture I have of the half wall and gates in it, is of Katie standing beside it...and not really looking like Little Bo Peep.

Travis, Yes.  We both think alike when it comes to our sheep barns!  I did not mean to say that Linneus has any applicable building codes for outhouses.  Still, as a new farmer, I refer to general codes to guide me in choosing materials, methods, etc.  Especially when it comes to fastening rafters, collar ties, etc., I use the recommended number and sizes of nails, screws, and whatever.  But as you can see, this pole-barn sheep house is pretty rustic.  There ain't a straight line or flat surface to be found on it, lol!  But it will shelter my thirty animals and give me room for tending to them.  My main goal was to be able to use my small tractor for cleaning out.  Right now I have a small sheep house and in the winter it is just too difficult to clean it.  Then, come springtime, I have to dig and cut out fifteen inches of compacted manure and hay.  It is a horrible task and one I hope to not do again.       So, after a day of research and advice, I will be scissoring the rafters on top of the ridge beam.  But I am yet to decide whether I will use 2x8 dimensional rafters or use round timber.  I have to resolve the issue of perlins for round rafters.  I have not yet figured out how to get perlins in without also needing posts to support them.  I sort of want the house bays to be clear for the tractor.  

If the rafters are fastened securely together at the top, and the ridgepole is wussy, the roof functions like a truss, depending on the rafter-ties as the bottom chord of the truss(cross-pieces at the bottom of the rafters) to stop the roof sagging and the walls splaying...

But if one has a beefy ridgebeam and center supports under it, you can treat the roof like a pair of shed-style single pitch roofs, that happen to be next to each other, and omit the rafter ties. With a beefy well supported ridgebeam the center won't be able to sag.

If you have a sufficiency of posts to support the ridgebeam this might work out cheaper.. it also increases headroom with removal of rafter ties.


As far as fastening the rafters, I've done the notching thing, once. Kind of slowish for me, but I had zero experience.

Perhaps you could use Travis's method, or a chainsaw with ripping chain, to put two flats at the angle of the rafters onto the ridgebeam? Obviously less secure than a nice notch and birdsmouth, but a time saver; when I do this, I take care to use beefy fasteners, and to birdsmouth the other end..

As far as trying to use roundwood.. if by purlin you mean a supporting beam partway between the upper and lower wall...

Seems like the only way to support this without more posts, is with bracing leading back to the existing posts.

Probably the most practical way to implement this without buying dimensional lumber would be trusses built from roundwood.

But winter is coming! How much time do you have to spend on saving money?


(Here purlins are usually the dimensional lumber on top of the rafters/trusses, the ones that the steel roofing is fastened to...)

Dillon, my use of the term, 'purlin,' was erroneous.  Indeed, as you saw, I meant an additional beam running the length of the sheep house to prevent sag in heavy, round-timber, rafters.  I do not believe that I have space in the two halves of the sheep house to install the necessary posts to support such beams.  Even using supports stemming from a center post would not seem to solve the issue because those supports would end up too low.  As you can visualize from the measurements I gave, this is a somewhat low-ceiling barn, a sheep house.  So, to my mind (and, again, I am no engineer), I can only use my free round-timber rafters if they would be stiff enough to not sag.  I suppose I could use 6" round timber and get away without a support beam.  But that is a lot of work.  That is finding a lot of trees in the woods, felling, etc.  Indeed, and as you pointed out, winter is not far down the road.  After much research yesterday, and help from this forum, I have decided to go with dimensional rafters, 2" x 6", on 24" centers, fastened just above the 9" round timber ridge beam using 1/2" bolts.  It is called 'scissor' style and considered perfectly acceptable by building codes.  There is no notching.  It is a real time saver.  I might have to buy some extra lumber for the box enclosure of the scissored rafter ends, but it is a relatively easy task and permits for nice ventilation at the roof down the entire length.  It will also be pretty.  I will have purlins- but they will not be structural.  The purlins will just  be for the metal roofing, set on top of the rafters.  I know I do not really need collar ties with this  plan.  Collar ties will really just provide a point to hang lights.  I will have rafter ties.  The only question now remaining is whether I should bump up the width of the rafters from 6" to 8".  Rafter calculators on the internet seem to suggest 8" -but the calculators do not take into account that I have massive, numerous posts and beams and rafter ties.  Dillon, thank you for your time and attention!

You will be just fine with 2x6 rafters.

My sheep barn has a much lower pitched roof, and I have 2x6 rafters panning the same length, BUT mine are FOUR FOOT ON CENTER. I have a little more leeway because my barn is subjected to high winds so thee is never a snowload, but it takes a lot of weight to break a 2x6 on edge. Keep in mind that this is a sheep barn, not for human occupency too.

I had another thought too for you Alden, but I am NOT trying to overwhelm you with details. I just happen to have your attention, and while I am thinking of things, thought I might present some ideas for you to consider.

The question I had is on flooring. I have concrete and naturally love it, but it can be expensive, especially for a 24x60 foot barn. But one thing you can do, is use Earthcrete, or make your own concrete. In this case after the barn is built you could figure out how many bags of Portland cement that you need, then spread it out evenly over your floor. Then take a rototiller and mix up the dirt/cement as best as you can. Then add in the water and rototill again. Then before it sets, trowel to the finish that you want. In this way, you will only have money in the bags of cement, and NOT have to do hardly any shoveling. It will set up nice and hard and you can clean out your barn cheaply. One thing I noticed about sheep on concrete is their hooves are so much better. Footrot is unheard of, and I just have to trim hooves once per year, when they are on their back for shearing anyway.

Travis, I am a glutton for the information that guys like you share on these forums.  I am sure that I am somewhat too brief at expressing my gratitude every time I get a response to a request for help here.  Truly, it is guys like you here that make it so much easier for guys like me to be doing what has made me so happy these last few years.  I pay close attention when those with knowledge and experience offer their advice.  It is a godsend for me.   Regarding the floor for the sheephouse, it will be just dirt.  I do not use bedding at all.  I will scrape out the top soil and dump in dead sand.  The dead sand does pack to a hard surface, but it is not as hard as concrete and permits a quick and easy raking out of the poop, which I like to do daily.  My sheep piss like horses, and there will be puddles here and there, so I just toss a shovel or two of more sand over those spots.  As for their feet, I have been lucky so far.  I know sheep should have rocky areas to keep their hooves healthy, but I simply do not have that available.  On some issues, I just pray!  Regarding the 6" wide rafters on 24" centers, I am hoping they will do for our snowload up here.  I bought this property with a wood shed that is 12' wide, set off the side of the house.  It has 2" x 6" rafters on 24" centers, a 5:12 slope, and has stood up well for decades.  So I am going to run with that and not lose sleep at night.  

Hey no problem on the dirt floor versus concrete. If nothing else, maybe down the road if you need to pour a concrete slab, you will remember a quick and easy way to do so with a rototiller.

My sheep are on concrete and I do not use bedding either. The waste enough from their hay to make the floor clean enough to sleep on. I just clean out every few days, and the sheep stay clean, and the barn does as well.

The biggest design that our barns have, is that they are wide open above, and draft-free down low where the sheep are. That keeps the new born lambs from freezing to death when they are born, and the sheep from getting chilled by the wind. Yet just a few feet above their heads, it is wide open so there is plenty of ventilation and the sheep do not get breathing problems. Its funny how some people think sheep need to be inside a warm barn, but their preferred temperature is 28 degrees, just like ours is 70 degrees. If it gets below 0 degrees, they burn through some more feed, but are still good to about -30 below zero. After that they might get frost bite on their ear-tips, but they are pretty hardy animals. You just have to feed them lots of hay when it gets that cold.

Travis, Yep, my Katahdins have tolerated temps down to -30.  And thankfully so.  I could not raise sheep if I had to worry about their warmth in these winters.  The price of lamb is ok, but just ok- if I have to spend even just a little bit more money to get them to market, it will not pay.  As it is, I really have to do my meat sales right off the farm if I want to make money on the lamb.