glulam beam vs HEB-steel beam

[Stefan_E]

When comparing a HEA160 with a glulam beam 90*405, the HEA160 beam has greater moment capacity but lower bending stiffness. The designer might not have considered deflection, or they allowed for greater deflections?

 

[shelby67]

The constructor achieved a deflection of 7 mm under full snow load/loading.

 

[Mäster]

"Box" it with a flat bar, this will significantly stiffen it up, if needed..

"All weldable materials are preferable to wood"

 

[shelby67]

I will have a 20mm gap between the window and the lintel to accommodate a maximum deflection of 10mm, which will probably never happen in my case.

 

[imported_Byggaren]

I will have a 20mm gap between the window and the lintel to accommodate a maximum deflection of 10mm, which will probably never happen in my case.

Or you can go up a notch in size to HE180A to avoid deflection and if you don't have space in height for such, you can use HE160B which has roughly the same data.
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Byggaren

 

[shelby67]

You mean that if I take a hea 180 instead of a hea 160, I won't get any deflection at all?

 

[imported_Byggaren]

You mean that if I take an HEA 180 instead of an HEA 160, I get no deflection at all?

An HE180A has almost double the Ix (rigidity) compared to an HE-160A. So the answer is yes.
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Builder

 

[shelby67]

The sliding door supplier (hajom) recommends a 20mm gap at the top!

According to the engineer I've been in contact with, I will only utilize about 40% of the beam with my construction, and with an HEA-160 at 100% load, there would be a deflection of 7mm, leaving 13mm between the window frame and the lintel, and that's only under full snow load, which is not many days per year here in the Stockholm archipelago!

Is there any other specific reason why I should still overdimension to HEA-180?

 

[imported_Byggaren]

The sliding door supplier (hajom) recommends a 20mm gap at the top!

According to the engineer I have been in contact with, I will only utilize the beam to about 40% with my design, and with a hea-160 at 100% load, deflection would be 7mm, so 13mm left between the window frame and the beam, and then only at full snow load, not many days per year here in the Stockholm archipelago!

Is there any other specific reason why I should still oversize to hea-180

No. Not if the engineer has calculated correctly and you do not intend to change the loads on the 'loft' that it concerns.
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Byggaren

 

[shelby67]

Yes, like a true svennson! it's probably just as well to oversize.

 

[Mäster]

At the risk of sounding repetitive, I got a good price on a 160, even free? So I would have gone for it, in case of doubt I would have reinforced it. I replaced a glulam that was poorly installed and too short with a standing flat iron, 300x10? Firmly screwed to two pieces of 2x8. The span is just over three meters over a doorway, supporting a cutoff beam, which in turn supports the upper floor and the roof...

 

[imported_Byggaren]

With the risk of sounding repetitive, if I got a good price on a 160, even for free?
then I would go for it, in case of uncertainty I would reinforce it,
I replaced a glulam beam that was poorly installed and too short with a standing flat iron,
300x10? Screwed into 2 pieces of 2 by 8
The span is just over three meters over a gate, supporting a cut-off beam, which in turn supports the upper floor and the roof...

I assume you have put the flat iron on its edge?
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Byggaren

 

[Mäster]

Initially tried, but it was so troublesome to get it upright, so I put it lying down instead..

No, I meant upright where I wrote standing...

And by reinforcing the whole beam, I mean welding,
Messing with planks like I did in the garage was not what I meant, just that an extra life on the beam makes a difference..

 

[imported_Byggaren]

I first tried, but it was so difficult to get it upright, so I placed it horizontally instead..

No, I meant upright where I wrote standing...

And with reinforcing the whole beam, I'm thinking about welding,
Tinkering with boards like I did in the garage, wasn't what I meant, just that an extra life to the beam makes a difference..

Then maybe you should Google 'Steiner's theorem' and see what effect it had on the composite beam, consisting of two 2"x8" pieces and 'crazy screwed', as they say, with respect to an upright flat bar 300x10? (If I understood you correctly.)

Also, the bending resistance for a rectangular profile according to the formula: bxh^2/6 can be useful. All regardless of wood and steel having completely different E-moduli which makes the interaction of steel/wood not the easiest to calculate.

Additionally, you have to take into account that the shear in the materials differs (which also becomes apparent through a comparison of the E-moduli).

You further write that "...an extra life to the beam makes a difference." Think...I don't believe old man Hooke would agree with you there. On the contrary. He would probably turn over in his grave at that statement.
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Byggaren

 

[Mäster]

Now I didn't calculate my project, but out of habit, I roughly estimated and used what I had on hand, and it worked, and became stronger than the previous solution that was there.

Does that mean my years of professionally welding life reinforcements and welding beams from flat bar, when desired dimensions were not available, were in vain?
Maybe I should visit the old workplace and tell the engineer and the guys that they're struggling for nothing...

We were talking about a 3.6 m opening on a small villa, right?