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  1. AaronMcD

    Wood beam, long main span very short end span

    Have a 16 ft heavily loaded PSL beam, simple span. Say I want to extend the beam a foot or two to simplify construction, and infill that foot or two. Will the moment cause by that cause excessive uplift or buckling of the trimmer studs? Or should deformation be low enough that it can be neglected?
  2. AaronMcD

    Snow fence needed?

    I don't usually work in freezing locations, but currently working on a house with a 45 degree metal roof, no drift or unbalanced load, just straight 30 psf sloped slippery roof snow load throughout. 1) Is a snow fence really needed on this roof? 2) If we use a snow fence at exit/entries (a...
  3. AaronMcD

    Wood biaxial bending NDS ambiguity

    Oh you're right. I hate how convoluted the NDS is when trying to figure out which factors to use on which properties. for which sizes. It's like a giant 3D matrix scattered around multiple chapters of multiple documents.
  4. AaronMcD

    Wood biaxial bending NDS ambiguity

    Where are you getting that?
  5. AaronMcD

    Wood biaxial bending NDS ambiguity

    A window header could be one. I mentioned a skewed purlin in my OP (ignoring diaphragm action to be conservative). 3.9.2 applies to bending and compression as well and looks a bit easier to plug into a spreadsheet than 15.4.1 Strong axis = fb1 And it would make sense to calculate F_be for...
  6. AaronMcD

    Wood biaxial bending NDS ambiguity

    Wondering if anyone has an answer to this. Biaxial bending is in chapter 3.9 of NDS. It has F_bE in the denominator of the last term. Go back to section 3.3.3 and this variable is a factor of some other variables: 1) It is a factor of the slenderness ratio, which is otherwise used to calculate...
  7. AaronMcD

    Holdown anchor through existing footing

    I glanced at a few but none long enough.
  8. AaronMcD

    Holdown anchor through existing footing

    That's an idea. There is a stem wall they would have to remove and replace. There is no push back to going underneath.
  9. AaronMcD

    Holdown anchor through existing footing

    There is enough thickness, it is a 16" wide by 20" thick footing. 10" is the maximum epoxy embedment and that is not strong enough for overstrength or ductility. Originally we assumed a 12" thick footing, and specified a new 16"x16" footing below with t&b rebar. Now that we know the existing...
  10. AaronMcD

    Holdown anchor through existing footing

    Wonder how you all detail a holdown anchor through an existing footing. Do you bolt it directly to the bottom of the concrete and allow deformation or crushing at the rough surface? Do you extend a distance below the footing and cast it in? Is there a need to use rebar or does a block of plain...
  11. AaronMcD

    Interior columns bearing on finished exposed slab

    The slab will be exposed as mentioned in the title. The anchor bolts have to be concealed. I suppose we could use leveling nuts and grout at the concealed steel columns. I was thinking it might be difficult to fit it within 5.5" stud width. Looking more into this, I am learning there are other...
  12. AaronMcD

    Interior columns bearing on finished exposed slab

    Designing a house. There are 8 concealed steel columns and 2 exposed wood columns at the interior slab. Many of the steel columns act as wood shear wall end chords as well as roof support (we have snow load at this location). Originally I have been designing this with continuous footings...
  13. AaronMcD

    Contractor will not provide rebar shop drawings?

    We always require rebar shop drawings, no matter the size of the project. On small projects, we often don't see any or expect to see any. Sometimes we don't even get steel fabrication/erection drawings. And sometimes when we do, the shop is so small that the "shop drawings" are just copies of...
  14. AaronMcD

    Buckling check needed for circular hole but not for square hole - ASCE spec for holes in webs

    I'm coming across this same issue as in this thread. Shear capacity with the hole is greater than 2/3Vp. https://www.eng-tips.com/viewthread.cfm?qid=454419 I'm wondering why this triggers a web buckling check, even if there is zero shear at the hole. I have a compact W8 and a 3 inch hole. It...
  15. AaronMcD

    Post-installed anchor edge distance in top of concrete on metal deck?

    Yes! Table 9, installed on top of concrete on metal deck, 1/2" anchor with 3" nominal embedment, 1 3/4" minimum edge distance. Interesting. The Hilti ESR has a note below the "top of concrete fill on metal deck" table, stating that for other diameters and embedment depths, refer to the other...
  16. AaronMcD

    Post-installed anchor edge distance in top of concrete on metal deck?

    The edge distance is 1 3/4" typically for Titen, but for some reason they list a much larger edge distance for the top side of concrete on metal deck. Absent an ESR, ACI uses 6d, and minimum edge distance can be reduced if designed for a reduced diameter complying with the smaller edge...
  17. AaronMcD

    Opinions on design

    Why not helical piles? The footing is wide enough to get staggered rows and they are very easy to batter.
  18. AaronMcD

    Post-installed anchor edge distance in top of concrete on metal deck?

    We are attempting to provide guidance for anchoring a manufacturer's skylight frame on concrete on metal deck. The manufacturer's frame has a flange that sits on the rough opening. The flange has holes for 1/2" anchors, 2 1/8" from the edge of shimmed opening. So ~ 1 3/4" from center of anchor...
  19. AaronMcD

    Diaphragm shear vs boundary nailing

    That's just the edge nails. I mean, look at case 3, if the framing is 24" o.c. you only have 5 nails along that side of the plywood. But the whole sheet has 27 nails - 27*1.6*1.1*95 = 4514 lbs = 564 plf. Only the 5 edge nails is 5*1.6*1.1*95/8 = 105 plf. Reality for a diaphragm is somewhere in...
  20. AaronMcD

    Trying to explain to non-engineers that it may be OVERKILL, but it is NECESSARY

    I had 2 projects recently that are relevant. Both on different mountaintops in NorCal. Both get strong winds. Both got extremely strong storms during construction. One huge covered outdoor patio with clerestory windows all around the top and a thin roof above that, cantilevered out 8 feet. A...
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