I need some help. I’m trying to lay down some roof sheahing. I have a 40 by 28 foot , foot print. My rafter tails (our over hang) are 12 inches. On my gable end trusses, I have to notch for look outs or eves. My rafter lenght is 16 feet 3 inches. My first question is where do I notch my look outs? 4 foot on center. I looked in a roof framing book and they suggest 32 inch on . If you use a heavy shingle. Such as tile. Which I’m going to use. My next question is. When I put down my first piece of sheathing. How do I support the out side corner. Do I nail a fashica board down the side of my look outs. And then nail on a fly rafter or rake board on the front. And butt joint the two. My rafters(or trusses) are 24 inch on centers. My last question is when I’m laying out my sheathing for my roof. And I’m using 4×8 5/8’s osb. How do I lay it out. I will be 6 inches short if I lay them out end to end on the 4 foot end. If I lay them out at the gable edge. I will be 6 inches short on both ends. Or for my first piece do I use a 9 foot sheet and cut it 8 feet 6 inches to allow for the look out. Thanks Hat
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Wow!
Sounds like you need the whole book, not just chapter and verse!
Let me condense - and this is just one way to deal with it.
I don't notch flying lookuts often but when I do It is at 24"oc. What I do more often is to buld a ladder eave on the ground or deck and carry it up to install after the ply- oops -osb is on and overhanging. I plop it tight under, nailing it to the end gable wall and the sheathing down to it. Cut the final sheathing after it is on. I use subfascia along the eaves and all this is in before starting fascia.
You can start the sheathing to break on any truss along the way. Whatever is waste on first row tells you where to start on second course.
Now - was this sheathing and truss package engineered for the weight of the tile and the live load? I've got prejudices for sure and I'm sceptical about tile on OSB over 24"oc. Sound like you might be in the deep south.
Excellence is its own reward!
piffin,
could you elaborate a little on why you build the ladder r/t build in place. I think I see advantages in getting a better (straight) line for your barge board. Is this faster too?
we use trusses a lot too, for example current job is 24" OC and typically notch the gable for lookouts 24" OC (overhang usually two feet+ here in Seattle), attach a 2x4 sub-barge and then a 2x10 barge and 1x2 shadow
best, GO
Main reason is because anytime you can build something on the deck and handle it into place for fastening, you are working faster and safer, IMO.
Also, If it is a short overhang, up to 12" and a short span, up to maybe 12' or so, you can support the barge rafter wwith just a subfascia and a structural ridge extending with the bottom notched. No need for fly rafters notcheed out..
Excellence is its own reward!
Piffin,
I mostly stick frame. When we do fly rafters I always extend the ridge out and notch the bottom.
The fly rafter is also the same size as the common rafter. On a 12" fly I notch every 4', something bigger I go 3'.
I always make sure the first sheat is as as big as we can get and the second sheat is whatever it works out to be as close as you can get to 1/2 of the first sheat.
I 've framed alot of contemporary homes where the fly rafter was the same size as the commons 2x8 or 2x10.
In that situation I would extend the ridge out as usual. Then I would extend the top plate out and just make an extra rafter and nail it. After that the sub fascia and fascia will help to hold it up + the 2x4 outriggers.
Let's say the fly was a 2x8, I would then nail 2x8 blocks sqare off the 2x4 outriggers in between the back of the 2x8 fly and the sheathing.
I've also done fly rafters where the top is for ex,; 2' and the bottom is 1'. In that case we used 2x6 outriggers and notched every 3', with 2x's sqare off the outriggers.
I've also built fly rafters on the ground and put the soffit on first whether it was AC plywood or 1x pine. Brought it up and nailed it in. No scaffold work ;-).
Joe Carola
Well, Joe, if you're making a list of ways to do it, don't forget building the barge rafter, fascia, and soffit as part of the wall on the deck before raising it...
Whew!, let me get my breathe, that was a heavy lift!.
Excellence is its own reward!
Adding to Piffin's post - Trusses do not get notched, although you can probably get an engineering workaround from the truss company (See Boss Hog). I normally order a drop gable truss which allows the 2x4 lookout, on edge, to pass over that truss and die into the next truss over. Some locales require a metal hanger at that connection point, some don't. Add an H2, H2.5 or H3 strap to the lookout where it passes over the gable and you're good to go. Fill in between the lookouts on top of the drop gable. Add the sub fascia to the lookouts and tie it to the eave sub fascia extension. Apply the finished fascia and a 1x2 PT at the top face to space out the drip edge from the fascia (that may be a local option) and then run your sheathing all the way to that edge. You will have some cutoff waste unless your framing and fascia measurements are acurate enough to allow everything to be on the 2' spacing of your trusses.
As for the lookout spacing, I use 24" oc and the starting point is determined by what you plan to use for your sheathing pattern. It's a good practice to have the joint fall on the lookout so you can securely nail the edges. Not all sheathing starts with a full 4 feet and where the joint falls depends on your overhang.
Some framing I have seen uses a single barge rafter from ridge to eave subfascia and a finished fascia on top or that. Cheapo, but still done. The theory is that the sheathing that overhangs the gable will be stiff enough to hold up that rafter but, guess what, it does sag. Build the ladder that Piffin mentioned if you can't do it otherwise.
Notching gables that sit on bearing wals is common practice around here. Doesn't really affect the truss, as long as it's fully supoported. But some building inspectors get sticky about ANY truss that's cut, so check first if you have a building department/inspector.
Personally, I like to cut a 1.5" deep by 3.5" wide notch at 4'O.C. up the rake from the subfascia. Then I run a 2X4 flat from the first truss out to the fly rafter. Gives you something to nail the edges of the plywood to.
I start the first sheet of plywood at the third truss in, and cut it to 7' long. (I'm assuming a 1' wide overhang at the rake) The next sheet I cut 3' long, so the joints are staggered.
As for "supporting the outside corner" - If the fly rafter and sun fascia are in place, it's supported. Not sure exactly what you're asking.
BTW - Are you pulling our legs about the 9' sheets of plywood? I've never seen anything in 9', except for 7/16 OSB. And there's no way you should be using that for a roof on 2' centers, especially with tile.
Lord, grant me the serenity to accept the things I cannot change, the courage to change those I can, and the wisdom to hide the bodies of those I had to kill.
Nope around here you can get osb and plywood 9' 10' in stock and 12' but you have to order the 12'. As a matter a fact I have a piece of 4x 10 15/32's or 1/2 inch sitting in my back yard now.
Did the long ply cost a premium?Jon Blakemore
With a 28x40 footprint you should be happy because you can lay out your plywood from either end each way. With a one foot overhang then the layout should still be 2 foot increments. The first piece will have to be cut at one foot increments so you will have a little waste no matter what. Layout should be pretty easy. Stagger your joints and use the waste as you go and you should be OK. Be sure not to break the plywood at the eave or overhang and apply the prescribed edge nailing into your frieze blocks for shear transfer..
Here at Lake Tahoe with heavy considerations for snow loads and earthquakes, the standard for 2x6 lookouts is at 16" centers notched into the gable truss. It is a big no no to notch a truss except for the gable truss where I come from. Underneath the flat lookout block is another 2x6 block perpendicular to the verge each side of the gable truss for that extra fortress like structure.
I prefer to stack the roof myself and forego the convenience of trusses. I use a ridge beam and lookout beams at the eaves and then you don't need those ugly lookout blocks. Add a few corbels down the rake as needed to support the verge rafter and you have a house you can look at and not wince. Maybe I am a purist but I think trusses are for amateurs. I am sorry, but on my crew if you use trusses or plywood siding, you go to jail and you do not collect 200 dollars.
Here in San Francisco you have to use engineered trusses. Earth quake contry. And you do have to pay more for the longer ply. But not a premium.
"......trusses are for amateurs."
Them's fightin' words around here, sonny.
Let's me and you out back of the tavern and I'm gonna open up a can of something on you. (see attachment).
If I'm not there in 5 minutes, start without me.
Boss, where's the censor? I think you're on to something here. Trying to #### with brian?__________________________________________
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Not trying to mess with Brian - Just poking fun.............After all, what is your hosts' purpose in having a party? Surely not for you to enjoy yourself; if that were their sole purpose, they'd have simply sent champagne and women over to your place by taxi. [P. J. O'Rourke]
Hey Boss top of the morning to you........I am interested in opinion of a couple of things about truss's on the job . If truss's come to the job on a roll off what kind of tension is put on the truss sideways and doesit have any effect on thier integrity. Have you ever heard of any problems with useing the boom truck to lift 10 to 20 sheets and set them on temporary brace's on top of the truss,s? From the how come dept ...wonder why there isn't a tag{label or marking } on the truss to show where to properly hook up the boom lines ,you ought to see some of the things framers can do to your truss's on the job. While I am at it some of the boom truck drivers are a lot smarter than they look tell them thanks for me and thank you.
Yo nails -
You're covering a lot of ground here, but...........
On rolling off trusses - Kinda depends on the situation, the site, the trailer, and how many trusses are stacked up on the load. Take a simple set of 40' trusses, a level site, and a good driver and they shouldn't be put under any stress at all. But take a big set of nasty trusses with too many on the load, and just about anything can happen. I don't see much problem with bending the trusses. It's generally a web gets caught in one of the rollers and breaks a bunch of them.
If you see a set that you think are damaged, the easiest thing I know to do is try to slide a dime under the edge of the plates. If the dime goes in, the plates are pulled loose. If not, they're most likely O.K.
Next thing you brought up was stacking plywood on the trusses. I know a lot of guys do that, but it can be dangerous. I was once involved in a job where a "pickup" contractor had a crane swing a bunch of plywood onto a set of large poorly braced piggybacked trusses. (Had a nice flat area on top) The trusses came down along with the 9 guys that were working on the roof. Some of them were hurt seriously. I call the guy a "pickup contractor" because all he had was a pickup - No insurance. The church ended up taking a big hit.
I've also seen roof and floor trusses damaged from setting too much plywood on them. There are guidelines for this in the following publication:
http://www.woodtruss.com/images/publication_images/ttbconstload.pdf
As for crane setting the trusses, and handling them - Each load of trusses you get probably has a copy of the HIB-91 summary sheet in it. Most of the time they get thrown away without anyone looking at it. You can see an online version of it at:http://www.eckmanbc.com/trusstech/tpi1.htm
That document provides guidelines for lifting trusses with a crane. But even the crane drivers employed by the truss companies largely ignore it and just use a strap.
Maybe I should have just made this a whole new thread............(-:The dead fish goes with the flow.
Back in the days when I was a framer, we woud lay out out trusses on 24" centers and make the over hang 12" on the gable end.
Thusly done you can cut a sheet to five feet and start the first course with 5' and the next with 3'.
No waste at that end.
some here will tell you that 2' is not sufficient staggering of seams.
they can all bite me! :)
but seriously, it worked fine and saved some ply.
you can spend alot of cipherin' time here and still waste plywood.
my 19.2 cents worth
Mr T
Do not try this at home!
I am a trained professional!
Hey it's nice to see theres an old production framer out there. Running 3s and 5s starting with an 8ft sheet gains alot of time eespecialy if the sheeting {or is it sheathing, never new what was correct term}is on the truss's and is gang cut and handed down. By the way do you know any tech. reason's for even having a gable overhang?
Reason for gable over hang is same as for eave overhang. It keeps water off the windows and siding better..
Excellence is its own reward!
There's got to ber a joke in this title someplace about a she thong laying out on the roof.
;).
Excellence is its own reward!
Thats why you can't figure the layout ....
The ultimate distraction.....
The "Y"
T
Do not try this at home!
I am a trained professional!
Edited 10/9/2002 7:55:03 PM ET by Mr T
Piffin ... hump day , I mean half the weeks over . Gable overhangs me thinks are one of those things that we do build or design because it's allways been done . I understand the obivious of keeping water off windows and siding but if the overhang is 1 1/2" or up to 2 or 3 ft what good does it really do on a 2 story house ? Seems like we should build a second over hang above the first level? Did you ever notice a lot of water problems in basements start from gable ends or corners usually because of back fill grade dropping as the fill settles over time?
Well, my house is a two story with about a fourteen inch gable overhang. I know that the end wall gets rain when the wind is blowing like in a Noreaster but in an average snow or rain, I can stand right outside that door and watch the dog do her busines while I wait for her with hardly a drop hitting me. That's fairly effective for 18 feet up to the overhang. I know that two inches wouldn't serve me as well.
In summer, the more shade it provides , the less R my insulation has to do also..
Excellence is its own reward!
Isn't that your nineteen and three sixteenths worth?
LOL.
Excellence is its own reward!