I joist to steel beam

[Bammer25]

I have 16 inch I joists (framing package by local lumber yard) and I am designing steel beams to carry the loads. They don’t want the joists bearing on top. Trying to figure out the best method. I keep telling myself the beam needs to be as deep as the I joist, but a w16 will be borderline slender for what I need. Also if I pack out in between the flanges with wood, I’d have to use LVLs or not have the wood bearing on the bottom flange. That seems like an expensive way to block. I will bolt through the web, regardless. Top flange hangers are an option with a wood nailer on top, but would that still count as constant compression flange restraint?

What do you guys normally do?

 

[XR250]

but a w16 will be borderline slender for what I need.

What does this mean? Also, is the beam loaded from one side or two?

 

[EngDM]

They don’t want the joists bearing on top. Top flange hangers are an option with a wood nailer on top, but would that still count as constant compression flange restraint?

What do you guys normally do?

Top flange hangers. Still counts as lateral restraint so long as the hangers are installed correctly and the nailer is fastened adequately.

 

[jerseyshore]

I have 16 inch I joists (framing package by local lumber yard) and I am designing steel beams to carry the loads. They don’t want the joists bearing on top. Trying to figure out the best method. I keep telling myself the beam needs to be as deep as the I joist, but a w16 will be borderline slender for what I need. Also if I pack out in between the flanges with wood, I’d have to use LVLs or not have the wood bearing on the bottom flange. That seems like an expensive way to block. I will bolt through the web, regardless. Top flange hangers are an option with a wood nailer on top, but would that still count as constant compression flange restraint?

What do you guys normally do?

All the above depending on loading and sizes. Sometimes we weld the hangers on top. Sometimes directly attaching to top plate like in the Simpson book. Face mount hangers work as well. LVL packing is used all the time around here. The difference in cost seems like splitting hairs IMO. If the joists are flush framed from each side, where can the beam even go?

 

[Bammer25]

What does this mean? Also, is the beam loaded from one side or two?

Slender flanges. As in b/t ratio

One side in this case and a wall on top

 

[EngDM]

Slender flanges. As in b/t ratio

Could go with a heavier W16? Your beam depth also doesn't necessarily need to match joist depth.

 

[XR250]

Slender flanges. As in b/t ratio

How is this controlling?

 

[Bammer25]

How is this controlling?

It doesn’t control. It just seems weird going with a tiny w16 when a typical w10 works. Hence my whole creation of this thread asking others how they typically do this sort of thing. I can think of 3 or 4 ways. Just hoping for some revelation on what is the most common way.

 

[jerseyshore]

I just use what steel beam size works in this scenario since most of the time in new construction we'll have a 2x top plate and can use the top flange hangers. It's different in a retrofit type situation of course.

If you're worried about it being loaded only on one side just run a quick torsion calc. I doubt it will make much of a difference. Maybe bump it up a size or two.

 

[XR250]

It doesn’t control. It just seems weird going with a tiny w16 when a typical w10 works. Hence my whole creation of this thread asking others how they typically do this sort of thing. I can think of 3 or 4 ways. Just hoping for some revelation on what is the most common way.

I still don't understand. A W16 are not tiny. A typical W10 for me is a W10x15 which IS tiny in comparison.

 

[Bammer25]

I still don't understand. A W16 are not tiny. A typical W10 for me is a W10x15 which IS tiny in comparison.

Ok well I don’t know what else to say to you. Thanks

 

[Eng16080]

I keep telling myself the beam needs to be as deep as the I joist

Why? I would find a beam size that works, add a wood nailer on top, and use a top flange connector for the joists. As mentioned by jerseyshore, run a torsion check if necessary.

 

[Bammer25]

Why? I would find a beam size that works, add a wood nailer on top, and use a top flange connector for the joists. As mentioned by jerseyshore, run a torsion check if necessary.

Thanks. That’s what I’m doing. I guess my first option in my head was to fill the flanges with a nailer and I didn’t want the bottom of the hanger below the beam

 

[XR250]

Honestly, you typically want a slender beam in this case as it helps mitigate torsion due to less eccentricity. I would not bother doing a torsion check unless you have torsional restrain at the support - which you typically do not in residential (at least I don't)
I am not a fan of top flange hangers on one sided loading conditions as there is little to resist the torsion. Really depends on where the wall is located on the beam and if that can be made to offset the joist load eccentricity.
This is what i have done in some cases to save money on padding out with an LVL so face mount hangers could be used. Don't know if it actually saved money though. It is a W16x26. Can also use 2 layers or plywood for the padding.

 

[Eng16080]

The detail above is also a good one, and one which I've used many times. I personally wouldn't sweat using a 16" LVL web filler, but multiple pieces of dimension lumber works well if that is a problem. If the difference between the two is needing another row of bolts, that might offset any cost difference between the dimension lumber and LVL.

I'd consider the face mount connection as providing some degree of torsional restraint for the beam.

One small downside is that with the wall above, you'll also need a top flange nailer, and bolting that will cause some congestion with the web nailer.