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Discussion Starter #1
It wasn't until *after* my lumber was delivered that someone suggested ordering trusses. I am now staring at a bunch of lumber, trying to decide what is the easiest way to frame it. My plan calls for 2x6 rafters and 2x6 ceiling joists, and a 2x8 ridge beam. The building is 16'x16'. If I face nail the un-notched rafters to the ceiling joists and probably put a 2x4 across the top to make a trapezoid (and make it stable for moving), will that pass code? I was planning on notching the rafters where they rested on the cap plates, but would I still need to if I'm building trusses? Or am I better off notching and/or building trusses? :confused:

I guess I'm looking for the most efficient (and within code) way to do it. I want to do as much on the ground as possible before drafting cheap laborers to lift. I'm pretty sure one person can't do it by themself (correct me if I'm wrong).

Thanks.
 

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Let's start with terms so that we are on the same page. A roof frame (not trussed) looks like the letter A. At the top of the A is a ridge board, coming down from the ridge board are common rafters and at the bottom they are connected by rafter or collar ties. The notch that you are refering to is known as a 'birdsmouth', I don't use them much anymore preferring to anchor the collar tie to the top plate.
To materials; 2X6 is fine for the rafters. I always build on 16" centers and can get away with a 2X4 ridge board, notching the rafter tops is stronger construction. For the collar ties I would stick with joist dimensions which would be 2X8 for your size project. You WILL use the space for storage at some point, do it right now and avoid heartbreak later.
Assembly: Make your basic A frame; Make a full scale layout somewhere, a concrete driveway and chalk lines work well and go into mass production. Cut all of the rafter tops at once, then cut the bottoms. Do the same with the collar ties, I use bypass construction on these and glue AND through bolt. This is the major stress point of a roof and I don't fool around. I rip the appropriate bevel to the top of the ridge board. Lay the parts out on your marks and start gluin' and screwin'. I left out the ridge! I cut plywood triangles and glue and screw those to the ridge and make the cutout for the ridge beam later but before you are ready to raise them.
I'm 53 and bordering on decrepit, I built a shed of nearly the same dimensions solo last year and have another planned for this year. Drag it over, lift one end and slide it over. No big deal.
 

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Discussion Starter #3
Okay, I think we are on track with the terms. I do have a couple questions, though.

1. The collar tie *is* or *can be* the ceiling joist? When securing it to the cap plate, do you use a bracket or toe nail?

2. The 16x16 building is actually a 12x16 building with a 4' porch. Therefore the span for the collar ties or ceiling joists is 12' and 4'. Would that allow for 2x6 instead of 2x8? I kind of already have 2x6's.

3. Can/do you put a collar tie close to the top also?

4. How many bolts do you put through where the rafter crosses the collar tie at the cap plate?

I really like the idea of gluing and bolting, but more importantly the plywood triangle at the top, which would allow me to set all of the rafters before dropping the ridge beam in?

I haven't yet put my walls up, so I have a nice big and flat assembly area.

Thanks a bunch.
 

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Hi Neal,
In most municipalities it is not legal to build your own trusses unless you submit engineering to your building department. 2x6 rafters at 16"OC with a 2x8 ridge sounds good but you need a birds mouth cut at the top of the walls.
Next install a cieling joist of at least 2x8 and half way between the ridge and cieling a 2x4 collar tie. You then should install crossbracing mid span in the cieling joists.
 

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Discussion Starter #5
If I preassemble the rafters and collar ties before putting them up, then they are not actually trusses? :confused:
 

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One person should be able to stick rafters in a 6 foot (half the span) area period. Waste of time and money building trusses for a small job. Even at a 12/12 pitch this would be to easy. I have only had to go 16 center on rafters on one job in ten years. That is because the prints came from a magazine that was some midwest code. But the rafter were 2x8 or10 because of head height issues.
Even had to put in let in on a sheered wall. sheesh
 

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Couple things

"1. The collar tie *is* or *can be* the ceiling joist?"

No, no, no, no, no, no.... Trust me - don't go there. You start into this thinking and you'll make the mistake that some architects around here do - putting ceiling joists to far up the rise of the rafters. What does that cause? Roofs will start to splay out.

"When securing it to the cap plate, do you use a bracket or toe nail?"

You can secure the cj's with a toe nail.

"Would that allow for 2x6 instead of 2x8? I kind of already have 2x6's."

You really need to check your span tables for what your areas call for.

"Can/do you put a collar tie close to the top also?"

Yes, as long as your ceiling joists aren't above 1/3rd of the rise from the top plate.

"How many bolts do you put through where the rafter crosses the collar tie at the cap plate?"

You would be fine putting a couple nails in the collar tie.


Tim
 

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Glad that you asked that Joe.
A birdsmouth take a lot of time to cut, it also moves the apex of the angle between the rafter and the collartie further in over the top plate and leaves less area to be fastened with tiedowns.
In response to other questions; The collarties in smaller buildings are often used as joists which is why I prefer to oversize them. I always use brackets when installing the collarties and hurricane straps as well. Oversize the rafters and further reinforcement is unnecessary leaving an open attic.
I set 16"OC for three reasons; 1) I get more connections to the top plate, 2) even 5/8" ply on the roof eventually 'scallops' and looks dreadful when 24" OC and 3) if you want to use the collarties for joists this is the only way that anybody is going to allow it.
Titebond II, Gorilla Glue, epoxies and 2 3/8" bolts per connection have satisfied my building dept. You won't break these joints without destroying the wood.
It's Teetorbilt, 200 MPH shed.
 

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Teetorbuilt,

I've been a framer for 20 years and never heard of anyone not cutting a birdsmouth before until a couple weeks ago and that was because the framers screwed the job up and didn't know how to cut a birdsmouth but simpson supposidly makes a hanger for that but I've never seen one and framed every single house and addition using birdsmouths without any problems . Are you saying that you don't cut birdsmouth on your rafters and use some kind of ties to hold your rafters in place?

I know out in California they use ties all over the houses they frame I guess for earthquakes but they still cut birdsmouth in there rafters. If simpson does make a hanger for a rafter with no birdsmouth I think it would take longer to install the rafters. Your saying it takes to much time to cut a birdsmouth but it can't compare to how much time it would take to nail a simpson hanger on every single rafter mark on the top plate and then I'd love to see someone set a 24' 2x12 rafter in place because you would have to mark a line on every rafter where the H.A.P. cut would be so that you can nail the rafter in the right spot on the hanger and then you have to nail the hanger into the rafter where as with a birdsmouth you pull the rafter up until it hits the heel cut and nail it in your done. And I say it's stronger if the rafter is nailed into the top plate and along side the ceiling beams.



Joe Carola
 

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Joe Carola said:
Teetorbuilt,



I know out in California they use ties all over the houses they frame I guess for earthquakes but they still cut birdsmouth in there rafters. If simpson does make a hanger for a rafter with no birdsmouth I think it would take longer to install the rafters. Your saying it takes to much time to cut a birdsmouth but it can't compare to how much time it would take to nail a simpson hanger on every single rafter mark on the top plate and then I'd love to see someone set a 24' 2x12 rafter in place because you would have to mark a line on every rafter where the H.A.P. cut would be so that you can nail the rafter in the right spot on the hanger and then you have to nail the hanger into the rafter where as with a birdsmouth you pull the rafter up until it hits the heel cut and nail it in your done. And I say it's stronger if the rafter is nailed into the top plate and along side the ceiling beams.



Joe Carola
In Washington they make us put one on ever truss or rafter it either has to be a simpson h1 or h2 clip. Under UBC we had to put it on every other one. Now we have to put them on every one and on the outside before the bird block is put on. Makes block and roll production impossible. Oh and btw hitachi makes a positive placement nailer for metal fastening products. The nails for them are expensive (same paslode nails). But I have used a S-B one that has nails that are resonable priced. Makes hand nailing and the palm nailer obsolete. Thought the palm is still nice for place that are hard to get to.
 

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Yes. But if trusses can be used there used and the big truss factory competition there cheap. If rafters are used it's for the vaulted effect. Usually Hipped also. For r-value we use 2x12 with a min of 3 inch seat on the wall. Also because we have to match up our rafters with trusses alot of the time a birds mouth is required. These are usually small areas were nothing over a 2x6 is required and they can get the r value they need.
 

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Joe, Let's go back to the original structure which is a 16 X 16 shed. It does not even qualify as a garage as autos are catorgorized as having a length of 17 ft.
Sheds often utilize the collarties as joists for storage purposes, all of my designs do because I know that sooner or later somebody will store stuff there, possibly lots of stuff as I do.
Perhaps you can enlighten me as to the value of the birdsmouth as I see little value to it considering modern construction.
 

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"Perhaps you can enlighten me as to the value of the birdsmouth as I see little value to it considering modern construction."

Modern construction is still stick framing roofs and there's probably millions of houses with rafters that have birdsmouths. I'm not an engineer but your the only person who seems to think that rafters don't need birdsmouths. They must mean something if every stick framed house has birdsmouths in them and every architect draws plans with them. Can you tell me why every house has them and you think they don't need them. Are you an Engineer or an Architect or Builder and if so can you answer my question I asked before, do you cut birdsmouths in your rafters or do you design and draw plans without birdsmouths in the rafters? Forget about trusses we're talking stick framing roofs.

I'm framing an addition with a 2x8 front wall 16' high with 24' 2x12 rafters with a catheral ceiling. Are you telling me that you wouldn't cut a birdsmouth in those rafters and nail hangers in first and struggle to line up the H.A.P cut line and then nail the hanger into the rafters?


Joe Carola
 

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Joe, my profile is public, click on my name and you will have my credentials.
I am progressive and most of the people that you state just don't want to make waves or the specs are already in their software. I live in a dynamic area (hurricanes) and am always looking for better solutions after watching roofs being ripped off. My shed, built 2 yrs. ago was untouched by 2 hurricanes and my neighbors tree falling on it (large Maple).
I don't care how it has always been done, never have. I only go with what makes sense.
 

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"I don't care how it has always been done, never have. I only go with what makes sense."

You asked me a question and I gave you my best answer. I asked you a question twice and you didn't answer me. You don't care how it has always been done and you only go with what makes sense but your not telling me what makes sense and why. I'm all for doing what's right and if there's changes I will do them and in 20 years of framing there's been quite a few changes but never seen rafters with no birdsmouths.

So can you answer my question again so I can see if it makes sense since your a Remodeler of High end homes you must cut rafters, so do you cut birdsmouth in them and tell me if it's stronger and faster because you said it takes to much time to cut a birdsmouth?

Joe Carola
 

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I can see were a birdmouth has little value on rafters that are 2x6 or 8. You still put a seat in teh rafter right?
Any thing over needs one I thought. The building dept. don't like the back edge of the rafter hanging over the wall as it devalues the strenght of the rafter.

Also what stops the rafter slipping down off the wall? Not a simpon clip. But I live in a area that has high live and dead loads due to snow. Even thought it doesn't snow much any more.
 
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