Timber Drag Strut Tension Transferred around Pass Through Column 1

[KootK]

I find myself stymied by what must be a fairly common condition. There's gotta be something better than this. This is all concealed stuff so I really don't want to drift off into custom hardware etc. I guess I could try to spec a non-full height hanger to allow a side mounted strap to pass through I suppose. I don't love that though and I'm going to have to deal with straps running both directions at the same joint.

 

[jittles]

Generically speaking, I find that using back-to-back tension ties/hold-downs often helps in these situations. You can get yourself a bit of stand-off from the faces of the beams to allow a threaded rod to get drilled through the perpendicular beams. If that's not enough, you could add a short length of another LVL ply to build it out another 1-3/4" if you need to.

If you get too far off the center-line of the drag for comfort, you could plop another set of ties on the opposite face of the beam, making the drag load nearly concentric through the connection. I honestly rarely worry about that part of the equation in a typical wood structure.

 

[CANPRO]

Sounds like jittles has a better solution than my idea, but I’ll throw my idea out there anyway...

You could run your steel angle continuos past the column (angle fastened to drag beams and column), which would transfer your drag forces and then let the perpendicular beam bear on the horizontal leg of the angle. If you need to transfer drag forces in both directions this wouldn’t work...and re-reading your post it seems this might be the case.

 

[txeng91]

Are you using Simpson-type concealed flange hangers. If so, do you think there might be an issue with the fasteners in perpendicular beams interfering with each other?

 

[NorthCivil]

Not a fan of strapping to an L angle, screwed to dragstrut. its very "bitsy"

do like the hold down idea by jittles

 

[KootK]

Thanks for the advice gentlemen.

Generically speaking, I find that using back-to-back tension ties/hold-downs often helps in these situations.

That's an excellent idea. The trick will be getting enough standoff to clear the crossing hangers.

Not a fan of strapping to an L angle, screwed to dragstrut. its very "bitsy"

Thanks for the feedback. I can't say that I disagree, it does feel pretty cobbled.

You could run your steel angle continuos past the column (angle fastened to drag beams and column), which would transfer your drag forces and then let the perpendicular beam bear on the horizontal leg of the angle.

Creative. I don't like the angle as beam bearing though. Then I've got to design that and likely upsize it a fair bit for that function.

Are you using Simpson-type concealed flange hangers. If so, do you think there might be an issue with the fasteners in perpendicular beams interfering with each other

Yes and yes. I hadn't considered this previously though so thank you for pointing it out. Column is 5.5 x 5.5 to opposite side hangers shouldn't be a problem. How concerned out one be about interference from crossing nails? I almost feel as though they should kind of "find their way" around one another. I'm not sure if I could sort out hanger options that would intentionally not conflict. I'll try though. It also kind of makes me wonder if there are interaction affects in the column even if the nails don't conflict.

 

[Celt83]

something like a Simpson LTT/HTT and a Thru bolt may be an option, similar to Jittles approach.

Open Source Structural Applications:

https://github.com/buddyd16/Structural-Engineering

 

[dhengr]

Celt83:
Do you moonlight as a cleaning lady? Just wondered, because you sure can’t clean that detail up much better than you have. You might consider adding some heavy square stl. washers btwn. the bolts and the LTT’s/HTT’s just to help get the load from the bolt center line to the strap surface without bending/prying on the strap flange.

 

[txeng91]

Yes and yes. I hadn't considered this previously though so thank you for pointing it out. Column is 5.5 x 5.5 to opposite side hangers shouldn't be a problem. How concerned out one be about interference from crossing nails? I almost feel as though they should kind of "find their way" around one another. I'm not sure if I could sort out hanger options that would intentionally not conflict. I'll try though. It also kind of makes me wonder if there are interaction affects in the column even if the nails don't conflict.

Yeah I see what your saying with the nails being able to work their way around each other. Worth noting that with 4 beams your looking at upwards of 80 16d Nails all in that small space, so there could be some installation issues as well as nominal reduction in flexural capacity in the column. I think as long as you consider eccentricity from unbalanced loading and you have a little extra capacity to spare it should be fine. You may consider using HUCQ type with 2 1/2” SDS screws as it uses less fasteners and they are noted to be specifically designed for facemounting into columns and at ends of beams. In their catalog they have the HUCQ and LUC noted for this application where they don’t say anything on the HUC. Which from the looks of it the fasteners are closer to the edge of the hanger on the HUC and the detail they show with the HUC to column shows the flanges manufactured straight to attach into the side of the column.

 

[KootK]

You may consider using HUCQ type with 2 1/2” SDS screws as it uses less fasteners and they are noted to be specifically designed for facemounting into columns and at ends of beams.

Oh, I'll take that. And in the nick of time too. Drawing issue in the morning. Just let me know where to send the check.

@Celt: love it. the hardware may conflict with my the clerestory framing above I'm afraid. My bad for not mentioning that.

 

[jdgengineer]

Steel post with welded bent plates as beam hangers? Seems like this would avoid the crossing nail conflicts (which I don't love). And could also serve as the tension tie.

 

[txeng91]

Just let me know where to send the check

Normally I would let it slide since your posts have helped me broaden my knowledge on complicated structural issues (including your endless threads on trying to convince people that everything we know about hooked dowel anchorage is a lie). But I did see your sick brag on the high rise thread about having a $300k house so I’ll go ahead and send over an invoice.

 

[jayrod12]

...300k house..

Unfortunately I know where KootK presides, and 300k is a modest house in that market.

 

[KootK]

But I did see your sick brag on the high rise thread about having a $300k house so I’ll go ahead and send over an invoice.

Unfortunately I know where KootK presides, and 300k is a modest house in that market.

I employed some artistic license with the implied $300k number for the sake of smooth, non-offensive story telling. The unfortunate truth is that I do not own a $300K home. Rather, I rent a $850K home. I did a little hard living out of the gate. And one of the facts of life that I failed to appreciate is that, like a shitty credit card, there's a compound interest effect running on all of your early, bad life decisions. It takes a whole lot of future good decisions to tip the scales on a few bad ones made early. We'll get the home ownership thing sorted in the next couple of years but it will always be one of my major life regrets that my kids had to come of age without pets, without robust school district stability, and without the ability to put up boy band posters with impunity.