Building alone – roof advice needed
workalone
| Posted in Construction Techniques on
I’m planning a house 18′ inside diameter wall to wall, 50′ long. I’ll be working alone, so the roof trusses can be a problem. I’m thinking of a flat shed roof (20′ with the overhangs) because the trusses will be rectangular rather than triangular, and therefore should be easier to place. On 24″ centers, any idea how deep the trusses need to be? Is there a truss calculator on on the web?
Worse comes to worse, I’d settle for 16′ inside diameter.
Thanks
Paul
Replies
Well.....
More info is needed and you should probably hire an engineer.
I presume you mean 18' width (not diameter)
Depending on load factors for your area (fill in your profile so we know where you are) the size and spacing of your trusses will vary. Most truss manufacturers can manage this. You may be able to stick frame this as well... again depending on your loads.
Bruce
workalone,
You hopefully mean 18' dimension or span , or inside width of building.
18' diameter and 50 length doesn't compute very well.
That said, one person can stand 18' + wall widths long (span) trusses fairly easily as long as the pitch of the roof isn't too great.
Even an 8/12 pitch is going to net a truss that is just over 6' tall at the peak.
Start at one end of the building with a "post" attached to the outside of the building at center of the span that will be tall enough to reach above the peak of the truss. Have some 1 x 4 or 1 x 3 handy and cut into 1- 2' length plus a number 6' lengths.
Take the first truss, stand it against the post and tack it to it. Now nail the 2' piece of the 1x to the top of the truss , drag your next truss over and stand it, tacking the 2' piece of 1x stock to the top of it.
Now go to the ends and nail them off (after making sure you have the truss centered)
Go back to the center and nail a 6' piece across both trusses you have standing, this will leave a 4' piece of 1x hanging out towards where the next truss goes.
Drag another truss over , stand it , tack the 1x down on it , nail off the ends .
Repeat for all 50'.
yes there a truss calculator on the web , it called Bosshog
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BOB is always right, ALL HAIL BOB
Paul,
Since you will be working alone, why would you use trusses and kill yourself lifting up 20' trusses by yourself?
Stick frame this and it would be so much easier by yourself. It's only a shed roof and you wont kill yourself since your by yourself.
Framer, I don't think that since I came to this forum I have ever found reason to disagree with you but this time I do. An 18" (make it 22" with 2' overhangs) in my experience is lighter and easier to put up by myself than a lot of rafters I have set. Build a "cat walk", have the trusses set on the walls and go to it. Guess that is why we all come here, to hear the different opinions. They can't get your Goat if you don't tell them where it is hidden.
Edited 10/8/2007 6:39 pm by dovetail97128
He said that it's a rectangular truss, I take it. that means that it's the rafter and the ceiling joist all in one. How can that be lighter than single ceiling joist or a single rafter?Joe Carola
Framer,
You are correct in what you state. I read (and just now reread)the OP's post and took his statement to mean that he would be using the flat truss or shed truss as his choice because he was concerned about the weight of a gable truss. So I will go with your assessment , at least up to the point that the roof design is a very low slope roof requiring a shallow truss. I do wonder what a "I" floor truss TJI or similar would stack up against the stick frame.
They can't get your Goat if you don't tell them where it is hidden.
I'm going to say the stick built would be easier in this case, too. Getting the trusses up to the top plates to start the placement would be a PITA as well as the extra bracing required to keep the walls stable during the process. I do a lot solo and can't really think of a way to do even small trusses such as this solo and be comfortable with the process.
Maybe I'm missing something?
John,
Probably not you who's missing something, must be me. I have done a lot of framing of roofs using both trusses or rafters and joists over the years so I understand the work involved in both scenarios. I just shudder anymore at the thought of dragging green framing lumber up to the top of the walls and man handling it by myself. Old age must be setting in .
They can't get your Goat if you don't tell them where it is hidden.
Dovetail gave the down and dirty of standing trusses.
It helps to have your first truss standing securely against bracing that is as plumb and as solid as you can make it. Then standing up the rest of your trusses is a matter of accurate top plate markings and story pole like spacers at the peak and at other points on the slope as needed.
View Image
These are 30' 4/12 trusses. Drag 'em upside down, push one end up first and then push the other end up. Use a 2x with a crutch nailed to the end to push up the peak and toe nail another 2x to the botom chord to keep it from bending as you push the peak. Let the peak fall against the previous truss and under the story pole spacer.
Climb to the peak, push the truss away to the spacer mark and nail it off.
Repeat.
Edited 10/8/2007 8:15 pm ET by RalphWicklund
An 18" (make it 22" with 2' overhangs) in my experience is lighter and easier to put up by myself than a lot of rafters I have set.
Ok, I'm gonna go with Dovetail on this one. An eighteen inch truss should certainly be easy to set by one's self. Even if its 22 inches, I still think I could handle it alone.
=)View Image “Good work costs much more than poor imitation or factory product” – Charles GreeneCaliforniaRemodelingContractor.com
I'm STILL wondering how he gets those 2 foot overhangs with 18" to 22" trusses...
Yeh... That'll work.
Call Boeing,... they'll explain it
Luka, It is all in the illusion , watch my hands carefully now.
;-)
They can't get your Goat if you don't tell them where it is hidden.
Luka , A good truss supporter helps as well.
They can't get your Goat if you don't tell them where it is hidden.
<An eighteen inch truss should certainly be easy to set by one's self>
Remember in This is Spinal Tap, when the prop shop made the Druid / Stonehenge models 18" rather than 18' tall, and they had to have dwarves dancing around them?
Forrest
DUH!! .. Caught me again!
They can't get your Goat if you don't tell them where it is hidden.
There is a new metal product called "Stabilizer 24" that I have a sample of from the JLC show. Basicly you stand you truss up, place this spacer in the gap, and pound it in. Very easy to do one man, with perfect spacing every time.
If you space it right, you won't have to use H clips between your sheathing... well at least not where these bars land anyways.
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
If your hair looks funny, it's because God likes to scratch his nuts. You nut, you.
I typically stick frame and that is my choice.
But I have set trusses 24' long with a 3/12 pitch all alone. it is no fun, but doable.
of course, framing ANY roof all alone is no fun.
Get some help for one day and have some fun.
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
Workalone, if it were me i'd stick with a gable. I wouldnt design my roof dependant on how much help I had on truss day.
Trusses are surprisingly simple to set. I dont mean to say its easy but itsa not as hard as it looks. Everyone has given great directions on standing trusses give it a shot.
Also remember, help is usually only a 12 pack away. Call a friend for one day.
"I wouldn't design my roof dependent on how much help I had on truss day."Absolutely!
I was shocked to even read somebody thinking like that.Upside down, inside out and backazzwards thinking that one was.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I would much prefer to set a "normal" pitched roof truss of 18', than the flat top. I'm an old, weak and slow man and I could still set those trusses with little problem.
The 2' overhang would actually be a nice benefit because it would provide a rather wide margin of safety as I set the trusses upside down on the wall and swung them into place.
Actually, you will get a lot of good exercise setting that run of trusses.
My program would run something like this:
The gables would be built as one unit on the endwall, sheathed, papered and the overhang installed. I'd crank it up with two wall jacks, each set about 4' from the end.
So, when I started installing the trusses, I would have the gables up, braced and be able to swing the truss up and slap it against the gable as I rolled it.
The procedure to set the trusses are: 1) hang upside down. 2)Stand on the wall with one foot on the overhang. Grab the top chord and simultaneously pull up and push down with foot. The momentum of the peak will easily roll that truss upright. An 18' span is nothing and the leverage provided by the 24" overhang makes this a cinch.
After the truss rolls up, it will either bang against the gable, or the previously set truss and you set the truss for "endo", then walk out there and anchor the top with a lacer. I use studs for lacers. Studs are best because they store easily in the bottom chords. "Endo" means setting the heel at the outside of the wall.
After anchoring the top, I'd walk back to my ladder, put the truss on layout and put a couple of nails in it. I'd then go down the ladder and repeat.
The only variation would be the last two trusses which would have to be stacked before they are set. If you don't stack the last two, the last truss won't roll up because you'd be too close to the gable wall. It's not fun trying to balance a truss with the peak up while you walk up a ladder.
I would find conventional to be significantly harder and more time consuming.
Thats my story and I'm sticking to it.
jim
After
fka (formerly known as) blue
BTW welcome to breaktime.
I set 18' trusses with 2' overhangs on the doghouse last fall. I set them by myself.
Others gave you the routine to use, so I have little to add there. I did find that having a rolling bakers scaffold made the process easier. On an 8' wall a 6' ladder at each wall and the scaffold in the middle of the floor make the lift at any point a simple one man operation.
After hanging the truss upside down from the wall, you lift the peak up onto the scaffold. My scaffold is 6' high with the walkboard onthe top rungs. Climb up an lift the truss to the waitingspacer board nailed to the top cord of the previous truss.
It is a lot of climbing up and down ladders and scaffolds all day long, but very doable.
An 18' truss with a 4/12 pitch can be carried through a 3068 rough door opening easily enough and if they are 2x4 top and bottom cord, they are light enough for one man to handle alone.
I 60 years old, 6' 1" tall and only weigh about 155-160 lbs.
If I can do it alone, so can you.
Dave