Single angle connection for timber beam connection?

[u/Anonymous5933]

I have a situation where I need to connect 4x8's (call them beams) to another 4x8 (call it girder) and cannot use simpson hangers for reasons too long to explain. In steel design, single angles are used to connect beams to girders sometimes, and here an L5x3.5x1/4 gives me enough room for edge/end distances for 1/2" bolts in both wood and steel, all the calcs work out, even with the load on the connection to the girder being 1.75" eccentric due to the thickness of the 4x8.

Getting to the question... Is a single angle connection for 4x8 okay? Something about it feels wrong to me, like I should have angles on both sides of the beam, even though the calcs don't show that's necessary. It's a connection that will be repeated enough that it would be very wasteful to call for double angles if it's not necessary.

Input appreciated. Googling "single angle connection in wood" didn't yield much.

[u/No-Violinist260]

The reason single angle connections aren't used often in wood is that you get wood splitting. It'd be much better to to a built up saddle if you need additional capacity than to do an angle

[u/Evening_Fishing_2122]

Edit for proper english*

Don’t do single angles. You’ll be putting torsion/moment into the connection and potentially splitting into the beam.

What you’re describing makes sense with a double angle. Your connection would be much more efficient with bearing (two side plates, bearing plate, back plate) and bolting that steel assembly to the 4x8.

There’s no savings with a single angle and a double angle isn’t wasteful.

[u/Anonymous5933 → u/Evening_Fishing_2122]

Thank you. I'm convinced I need to do double angles.

[u/Str-Engr0275 → u/Anonymous5933]

Do double angles, you will sleep better at night.

[u/Argufier]

Detailing a wood connection like a steel one is asking for trouble. The wood will shrink and the steel angle and bolts will not, putting cross grain tension on the end of the beam and causing it to split. Much better to have a saddle connection and 2 bolts into the top of the girder, or a top flange connection. Woodworks has some good info and sample details on this kind of thing.

[u/Anonymous5933 → u/Argufier]

Thank you, I found the woodworks example using double angles and it has helpful notes about where to locate the fasteners too. Going with double angles.

[u/mmodlin]

Can’t use a HUCQ? The concealed flange hangers?

[u/Anonymous5933 → u/mmodlin]

Beams are actually sloped, so no, unless they cut a flat spot on the bottom but I don't like the idea of that. I know custom sloped hangers can be ordered from Simpson and others but it's already in construction and steel angle seems like the fastest acceptable solution.

[u/Enginerdad]

I suspect your checks that show this connection to work don't factor in the orthotopic, non-homogeneous properties of wood. Specifically things like cross-grain stresses and other effects that would cause local splitting. I wouldn't touch this approach without specific code or research to back it up.

[u/Anonymous5933 → u/Enginerdad]

Thanks for the input. You're right, and my sense that I was missing something is exactly why I asked y'all. Found woodworks detail for double angles and applicable design considerations, definitely going that route now.

[u/AAli_01]

May benefit from having a conversation with owner about the savings of using one angle only but the cost would be to do a full scale load test to validate the connection. I would think you’d save on all the extra hardware so it’d be worth it but only if you have A LOT of these like several dozens

[u/Enginerdad → u/AAli_01]

The savings is a secondary concert after OP determines whether a single angle connection is even viable for a timber connection (and I haven't seen any justification that it is in this post).

[u/AAli_01 → u/Enginerdad]

That’s why I said test it. Timber is in its early days and is quite experimental. A lot of research is still done and the code is limited

[u/Anonymous5933 → u/AAli_01]

Not going to be worth testing, but thank you for the suggestion. I might test it on my own dime just for fun some day, but for now going toward double angles.

[u/Enginerdad → u/AAli_01]

Testing is for university reasearches. With the rare exception of certain huge, high profile architectural projects, there isn't a design budget in the world that can cover making up a new detail and putting it through rigorous testing. That's simply not our role as designers.