Couple Timber Connection Questions 1

[Bammer25]

Hi again gents. My extent of timber post design has been limited mostly to decks, so I just use a basic simpson strong tie post base. No big deal. But what about when you have decent loads you want to spread out? I am not seeing a lot out there outside of me just designing a custom base plate with flaps that bolt up to the sides of the post.

Another one: what about a knee brace into a beam and/or column. Not seeing much out there other than a basic simpson piece that has very low capacity. I thought about using tension cables, but again, not entirely sure the best way to connect them.

Any tips from some of you more experienced wood guys?

 

[phamENG]

Knee braces are mostly the realm of heavy timber if you want to do them right. Unless you want some low capacity face nailed/bolted connections with a pair of 2x4s sandwiching a post and beam (probably with some shims somewhere), you'll be notching and bearing and through bolting at odd angles to the grain. Was there nothing the TFEC link I posted to your stilt cabin thread?

Tension cables can be problematic, especially if this is residential. You can spec pre-stretched all you want, but a residential contractor that doesn't know what a submittal review is will just buy the cheapest wire rope available. They'll pull it tight, all will be well, and then it'll relax and your building will get sloppy. And good luck getting them back out to adjust the cables. (If you do try it, you'll need an adjustable connection that can't come loose but can be tightened.)

As for 'spreading load out'...a steel bearing plate as you described is pretty typical. You could also look at using other species of wood with higher resistance to crushing.

 

[Bammer25]

Thanks for the reply. I guess what I meant on the base plate is (I haven’t ran the final numbers yet) I doubt I’m going to get enough shear and uplift capacity out of a basic Simpson timber base with a single anchor bolt hidden. Do you always go custom here?

Maybe I will go hybrid and design the lateral support out of steel angles. I doubt he will love the look.

 

[phamENG]

If Simpson doesn't work, I go custom. But that rarely happens. If the Simpson connector can't do it, the post and/or whatever connection is delivering the shear to the post will likely have trouble.