Building on a budget (zero) Rafter size

[Jeff]

Guys, this is just a tractor quad shed. I would ile to use some of the small fir or spruce I have dor 2 sided rafters. What size and spacing could I get away with?  Im using log screws for fastners. I have 9, 10, and 12" screws.

Span is 12ft.  
 Would 5"  every 4' do it?   I have some downed aspen I want to cut roof sheeting, and put a tarp over that for winter as no way I can afford steel this year.



 

 

[Jeff]

Front wall beam is 7x8. The back is 5.5x5.5

[barbender]

Idk about spans Jeff. Iirc, B. Allen Mackie, who wrote a lot of books about full scribe log building, had a book about round log rafter spans. From what I recall, full round rafters have way more strength than a comparable size board- a 4" pole is way stronger than a 2x4.

[Jeff]

I had planned on flattening them on 2 sides.

[thecfarm]

You don't want to know what I keep my tractor in.  :
But I will tell you anyways.
I took some cedar, left them round, maybe 8" across and I ran them across what you have, I think I only used 3. One on each end and one in the middle. Than I ran some hardwood trees about 6 inches on the big end and ran them long ways. One every 3 feet.
More then 20 years later and I never shoveled the snow off it is still standing. 
keeps the tractor dry.
My FIL calls it two by tree building.
I did brace the corners, but I used wire to hold everything down.
Budget building at it's best.  ;D
I even used an old wide belt from work for the roof. Then I had some old tin kicking around.
This building brought the value of my place down.  ;D  

[Southside]

Calling @Don P

[Don P]

Is Goetzeville close enough? Snow is 70 lbs per square foot + 5 psf dead load.
12' rafter span x 4' spacing= 48 square feet.
48 square feet x 75 lbs per square foot = 3600 lb snow load per rafter, uniformly spread out.

Assuming I can talk you into skimming just enough to make a flat on the top only, don't saw the underside fiber and double the strength ;), use this calc and lets see;
Log Beam Calculator (forestryforum.com)
... for just bending I'm getting a midspan dia needed is 9.5" in #2 Aspen

Cutting the spacing to 2' centers drops the midspan diameter to 7.5"

[Southside]

What about not sawing them at all, and using a 2x as a purlin come spring when it's time to put metal on it? The 2x could be shimmed to get a flat surface.  

[breederman]

You are not using the tractor etc in the winter? I'd use what you have and wedge a couple temporary posts on the middle of the span for the winter and call it done.

[Jeff]

This is what I want to use for rafters. Leaving them whole, seems like you would not want to cut a birds mouth. How would i handle how they pass over the beams? Connecting is no problem. I have plenty of log screws



 

 

 

[Hilltop366]

Whatever you end up doing you have lots of them so don't skimp over build, the load tables are the minimum to pass code/safety.

 To me the span stops at the point were the joist contacts the beam so the birds mouth is not part of the equation on the lower side, could cut a wedge to set the upper side on. At some point you may decide that cutting dimensional lumber may be easier but on the other hand we are not always looking for easier.

[Don P]

Yup, tighten up the spacing and use plenty. Try to stay fairly consistent in diameter, butts go low.
Skim to create an upper flat. Yes it is marginally stronger to leave it full round. Having done the shim it thing before, take the hit and skim the top surface.

Now saw a pair of rafters out of 2x boards of the same depth as your logs, roughly, birdsmouth, top cut and all, 2 finished rafters. You want to make the birdsmouth big enough to land on the beam well but never extend the heel of the notch inboard, don't over notch.

Screw a plank the length of the rafters across a pair of horses. Set your dimensional rafters top edge down on the plank and screw them from underneath the plank. Line up the birdsmouth cuts with a framing square across the plank You're making a trough to set the log rafter in.

Set the log rafter in the trough, smooth surface down on the plank, index surface to index surface, the top surface of the roof is what its all about so that is what this is all about. Line it up straight in the trough, butt end to the birdsmouth end. Using opposing wedges or screws up from the plank secure the rafter in the trough. Fire up the chainsaw and use the trough as your guide, try not to eat it before the last cut but you can screw on a patch pattern if you do. How would I know .



 

[Joe Hillmann]

Are you planning to put a bottom chord on the rafters?

Without a bottom chord tying the sides together I think the rafters will push the top of your walls out.

Right now I am building something similar.  Mine is 12 x 16.  I put up 3 log trusses that are triangles.  One at each end and one in the middle.  The rafters are 4 to 6 inch logs flattened on one end.  They are all slightly rotten cull logs from my house build.  I am using insulated garage door panels for the roof sheeting so I hope they can span 8 feet between rafters.  

Since you are checking it with boards you should probably go 16 inches or 2 foot on center to do it correctly but you could probably get by with 4 feet on center if you font need to walk on the boards

[Hilltop366]

Me thinks it's a shed roof not gable end, well that is what I based my comments on so I hope I was not too presumptuous.

[Joe Hillmann]

I took "two sided" to mean a peak in the middle.  But if it is a single sided shed roof my suggestion would NOT be strong enough.

[Jeff]

Been rafter shopping today.


 

[Jeff]

Rafter factory open. Skim cuts complete. Need to make another jig board. The sawmill bed is working nice for this. There is hardly any birdsmouth to cut

 .

[Jeff]

Beefy enough ?



 

 

[Southside]

Dosen't scare me at all. Of course it's not my tractor parked under there.  :D

[Jeff]

That crooked shed next to it with the same span using 2x6s on joist hangers has lasted 20+ years.

[Southside]

I can think of countless old buildings that were built like what you are doing that survived massive piles of snow growing up. As long as the roof kept the water off the lumber they never moved.

[Walnut Beast]

Looking good 👍 

[Ianab]

As long as the roof kept the water off the lumber they never moved.

That's the important thing for long term life. Keep wood dry and it stays intact for centuries. Let it get damp, and the clock starts ticking. Then some last 2 years, some last 30, but eventually the rot gets them.  

[Old Greenhorn]

Looks great Jeff! What's the spacing on the rafters, I think I missed that? What is your plan for purlins? Have any siding planned, or is that next year? You could hang tarps to keep the snow drifts to a minimum inside, just for the winter. I hear it can snow up there. ;D

[Jeff]

I had cut one decent spruce log into full 6 by heavy 6/4 because the log size lent itself to that. My plan this morning is to split them into 3"  wide to use for purlins.  The rafters ended up around, 38" center to center. Im thinking the purlins every 2ft.

That is exactly my plan. If I can't get walls up before the weather croaks out on me, i have the big heavy duty tarp I covered everything with last winter. If I can get purlins up for the walls, I could use that for this year.

[Jeff]

Tomorrow I'll start triming ends. Have to saw perlins for the walls yet.



 

[Don P]

Make the upper one on the back wall a 2x12  ;)

[Jeff]

Im actually thinking about cutting full 2" thick stock and plating the whole back wall. I can see a quad coming in hot, plus a solid wall will make a heck of a header.

[Jeff]

Hey, how about this. I put in a 2x6 treated bottom plate as a sill, then make a log wall on top of that? 3 side some more spruce and lag em in. I have a few hundred of those log screws.

[Jeff]

Back wall is 3" tamarack. I sawed the 6x6s in 2018  on my old property. Hauled the cedar home and built a fence leaving the tamarack for Gary. He never used it and it had been dead stacked 4 years. He said try it. Believe it or not, it was still plenty solid for this .


 

[Jeff]

We have roofage!



 

[Old Greenhorn]

 8) 8) 8) 8)
You've needed that for a while. That HAS to feel pretty good!

[Don P]

Jeff, on the back wall, if you run angle braces from the center of the overhead beam out each way to either post then nail each siding board to those as you install them it'll help rack brace and support the roof.

[thecfarm]

Is that the end you will be driving into?
Nice picture. Did you paint them clouds?  ;D

[sawmilllawyer]

Jeff, Looks like a pretty clean build site, or a cleaned up build site!!!Looks beefy enough for me but we don't get snow like that down here just high winds and ice storms, mainly.Keep up the good work.

[Jeff]

I have plans for diagonal bracing as I put the walls in. Found a $5 door at habitat that is going to be repurposed as part of a wall. 
There will be a slider that opens past that wall. Ill try to build the door to look like the door panel. The rest of the wall will be sided with the old 6/4 tamarack.

Mock-up.


 

 

 

 

[Jeff]

Here is da video

Building a Tractor Shed. From Trees to Sawmill to Shelter with materials on Hand! - YouTube

[barbender]

That's a great looking shed👍👍

[Jeff]

Coming along.  
This was end of day today. Cleaning ends up, trim, I still plan on some substantial diagonal bracing, then tarps for doors for this winter. Picked some up at harbor freight in the soo. I'm  ready for this to be done. Thought I broke my hand earlier, but it seems to be better after working all day with it.

 

 

 

 

 

[Old Greenhorn]

That looks SUPER! I love the way the door/window/wall came out. You have such a good eye for stuff like that!

[Southside]

Picked some up at harbor freight in the soo. 

 

 

 

 

Umm, we have a policy about a certain place that shall not be named here on the FF. Using lower case to avoid the automatic administration tool is unsportsmanlike conduct.  :D

[Ljohnsaw]

Harbor Freight is ok, it's the Northern place that is the lowlife scum of the earth.

[Old Greenhorn]

Southside, I think you just got put on 'Administrator's probation' for making a hasty call without careful reading.
 Don't feel bad, when I read I sometimes get the two confused also. But I was in town today and saw the banner on a building announcing a new Harbor Freight would be opening here in January. 8) This will save me an hour drive up the thruway every 6 weeks for the routine supplies. Plus the incidentals that come up.

[Jeff]

I love Harbor Freight!  I only need tools that last as long as I can still find em!

Also, they put a tractor supply in at home, right by the grocery store, on my way to everywhere.

[Southside]

Who was it that carried the Logrite knock offs?  Even used their pictures and all. I thought it was HF 

[chet]

Da place dat is da opposite direction of Southern Tool.   Starts with N  :D

[Old Greenhorn]

SS, I thought this was covered in the Administrator's handbook? :D :D Yes, it's NT, not HF. HF is our friend, NT, well, not so much.

[thecfarm]

There that should do it, but don't know how much snow you get.
Could always put a couple posts under some of them 2 by trees  :D to give you a piece of mind come February.

[btulloh]

Who was it that carried the Logrite knock offs?  Even used their pictures and all. I thought it was HF

I don't think it was either. Someone did that though. 
NT logging tools are junk, a waste of money, and dangerous. I don't think HF has anything like cant hooks or logging tongs.  
Actually NT has a lot of name brand stuff and is a good resource for me.  They also have those horrible logging tools. Caveat emptor.  I have no desire or reason to defend NT, but  I do get a lot of things there.  HF too.

[thecfarm]

It was that Northern place.
They even used Logrite picture to sell it. :

[btulloh]

Uh oh.  Must've missed that Ray.  That is a bad deal. 

[Southside]

It was the jeans that gave it away from what I recall. Oh well, but there still is a "he who should not be named".... :D

[Magicman]

Back to the tractor, etc. shed.  That is an awesome build Jeff, and mostly done in only a couple of weeks.  8)

[Jeff]

This is my bracing for the closed end. 2x10 base, then 3 6/4 6 purlins, then 3×6 tamarack attached to the base of the posts, and to the outside rafter.



 

[Jeff]

Putting in my temporary winter posts today. Just a v cut in the top and pushed verical. Ill have 3 in there before I seal it up.


 

[Magicman]

  I was wondering about the snow load.   

[Don P]

Well, if we're worrying, there would be a "beam" slung under and supporting all the rafters and winter posts stuck under that. You're kind of doing the same thing but your "beam" distributing the load to the adjoining rafters is the thin purlins and tin, too thin to do much work.

[Jeff]

It'll  be what itll be. I've been in several barns and sheds in this area that have been standing for over a generation that are built no better than this, so, I'll play the cards. I built what I could build with what I had.

[Jeff]

The rafters are 12 feet, the span isnt. Overall width is less than 12ft The pitch should count too.  It falls 19" from fron to back on that 12ft length. I got dark green steel to absorb heat. I put in 2 windows for some rays inside, and closed it in with black tarps.

I could not keep a folgers can with screws on the roof, it would slide right off

[Old Greenhorn]

Jeff, I have no doubt it will hold up just fine. It's not living quarters. If by some freak chance it doesn't, you'll fix it in the spring.
 I am contemplating doing a quick and dirty shed roof over my bigger drying rack to replace the tarp that got taken out in March's ice storm. Now that the wood has taken a severe beating on that I'd like to get something up quick with minimal work and lumber. If I get it done it will make your fine structure look like a brick 'latrine'.
 I think it looks neat, is very sound an will do your gear a great service. No question.

[thecfarm]

Looks better than what I have my tractor parked in. 

[Jeff]

So far we have had a lake effect snow storm with about 20" of snow, then a winter monsoon rain and a warm spell that melted everything, then last night we had 30mph sustained winds much of the night that I could hear battering my tarp walls.  I woke up this morning dreading what I might find, and found this.

My shed has super powers. It can store a sunrise.

[Jeff]

Looks like everything is goong well with the new building. Even the tarps are still in place and there has been some ferocious wind up there.


 

[doc henderson]

Even your Kansas state flowers are still standing.  

[Jeff]

They sure are. Moose high!!

[thecfarm]

Looks like as much snow as I have. Maybe a foot.

[Jeff]

That's what I'd guess Ray, storm coming tonight, but it could be rain os snow or ice.

[Magicman]

That's a purdy sight.  8)

[Jeff]

Last couple weeks I've been working on getting my building closed in. Last year I tarped it in, in the cold. Thiss year, I set my priorities wonky, and here I am again, pushing it. That's ok, I love it.

My end wall is going to be double doors, with a door in a door for winter, then swung open and left open durring poor sledding seasons. I'm looking for a couple old window panes to put in this end as it faces south, keeping the roof thawed off.

Tammy and I Got rained off this afternoon.


 

 

 

[Jeff]

Winter door in the summer door. The inner door will open to a post in the summer, in the winter itll lock down in the center leaving me an access door to lock everything down for the winter. Its raised off the ground to help keep any snow out until its all locked down.