Replies

1. 
   G.LaLonde | Dec 22, 2000 05:56pm | #1

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   Gene, Looks much better! Don't really need to install the top pieces on a slant tho....And don't forget to consider where the joints on the roof and drywall sheets will fall when you install the ladder crosspieces. Would be rather embarassing to have to start scabbing pieces in between!! Do you REALLY need 2x8's on top?

1. 
   Mark_T. | Dec 22, 2000 06:02pm | #2

   *Gene:In my area all stick built "walk up" floor areas require 2x10 joists 16" O.C. Non walkup stick built storage requires 2x8 16" O.C. Here you are proposing 2x8 joists 24" O.C. Not sure how/if that pretains to walk-up i truss attics, as I've never built one. Ron: got any comments on that?PS: Why are you not using storage trusses, or why don't you just stick build it?

1. 
   GeneDavis | Dec 22, 2000 08:05pm | #3

   *Thanks for the comments thus far. By design, the space is a "meditation loft," an equilateral triangle in cross-section, with a floor space about 9 feet square. There is a 36-inch square awning window in the gable end. We will make certain to place enough floor joisting in place to handle the loads, and in locations to pick up edges of sheeting. We will have our local engineer advise on the sizing of the top "ladder rungs," but as a structural engineer myself, I'll prefer to slice that bevel and orient 'em upright.

1. 
   blue_eyed_devil_ | Dec 23, 2000 02:12am | #4

   *Gene, why wouldn't you just throw in a 2x10 rafter instead of all the blocking?I'm not too keen on the horizontal blocking because the orientation of the roof sheating will be worng when layed over that four foot section. It might not seem like a big deal, but there actually will be a lot more play in that section. It would not be unthinkable that lowend fiberglass shingles would crack under the weight of someone putting their foot exactly in the right place.I vote for a 2x12 ridge, with a single 2x 10 rafter. An intermediate support could be added to cut the effective span in half.It's a lot faster too!blueps We've done a lot of them like this. Usually it is because the truss company screwed up and shorted us a truss!

1. 
   tedd | Dec 23, 2000 06:10am | #5

   *I think its worth meditating on.

2. 
   Boss_Hog | Dec 23, 2000 03:28pm | #6

   *Mark - I think it's silly for a building code to require a minimum chord size without regard to it's span between bearings or intended load. If I understand you right, that's the case here. When we design attic trusses, I always limit the lenght over depth ratio to 20 to 1 to try to eliminate bounce. Then the truss has to be run through the design program to determine wether it will work or not and what plates to use. I generally over plate attic trusses to allow for some overloading, and possible loosening of the plates from the vibration of people walking in it. (But that's just personal preference)Gene - I'd say your sketch is quite well done. What program did you draw that in ? I only have one suggestion that I've seen others do. If you use a size smaller cross members and hold them down 1.5", you can then run a 2X4 flat on top of them. That way your plywood still breakes on the flat 2X4 and goes down much easier.

3. 
   blue_eyed_devil_ | Dec 23, 2000 05:21pm | #7

   *Good suggestion Ron, and good observation too on the drwaing program. I too was impressed.blue

2. 
   GeneDavis | Dec 23, 2000 05:21pm | #8

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   For the friendly framing consultants that commented on my "Cut that chord!" thread, the attached pic is awaiting your review and comments. The cut-chord truss is gone, the adjacent trusses, 4'0" spaced, are doubled, and the ladder rungs are all 2x8s. Along the tops, they are spaced at 2'0" ALONG the slope, oriented vertically, and I'll do the framers a favor and rip the bevels myself. The things we do to accommodate the hallucinations of architects!