glulam beam vs HEB-steel beam

[shelby67]

I am going to open a 360cm hole in the exterior wall of a 1.5-story house with a gabled roof for a glass section, and I need to install a horizontal beam. According to Moelven's program, it will be a 90x405 glulam beam with 9mm deflection. Is there anyone kind enough to help me with a suggestion for which HEA or HEB steel beam to use instead of glulam to save height?

Thanks

 

[mycke_nu]

The answer can be found in this thread: http://www.byggahus.se/forum/byggmaterial-byggteknik/81812-hea-220-balk.html

 

[shelby67]

I have read that thread, it makes me a bit confused by the responses in it, as some suggest that the attached table is not reliable. Anyway, I have an existing beam (HEB 160) which I can buy cheaply Is there anyone who can calculate whether it could work instead of the glulam beam at 90x405x3600mm?

 

[imported_Byggaren]

As I previously reported in the thread provided by mycke_nu, it is not so simple to directly translate wood to steel and vice versa. You simply have to start over with load calculation, etc., to be able to determine the maximum bending moment if you do not have access to it from the calculation of the original beam.
_________________________
Byggaren

 

[shelby67]

If I use Moelven's program and enter all the measurements, etc., I get this response:

Dimension Deflection Dim column load Beam weight

LT 90x405 9 mm (L/410) 74 mm 31.5 kN 62 kg

LT 115x405 7 mm (L/522) 58 mm 31.6 kN 79 kg

I don't know if it helps any

 

[shelby67]

Dimensions:
Roof slope of the building: 45°
Width of the house: 7970 mm
Span of the girder: 3600 mm
Center-to-center distance of trusses (c/c in figure): 1200 mm

Conditions:
Safety class: 2
Climate class: 0 - 2
Roof construction: Concrete roof tiles / insulation / interior cladding
Self-weight of roof construction: 0.90 kN/m²
Snow load Värmdö: 2.0 form factor 0.55

 

[shelby67]

Contacted a constructor, found out that I need a hea-160

 

[petersk]

Beijer has a fun text about glulam and I believe everything that is on the internet.....

"Glulam is a natural building material that has become immensely popular in recent years. And it's not surprising. Glulam has essentially the same load-bearing capacity as steel but weighs only half as much. It also withstands fires better than many comparable materials, which is often reflected in insurance premiums. The image shows examples of glulam beams and columns."
http://www.beijerbygg.se/templates/BB_ProduktListingFlera.aspx?id=44213

Maybe I should add that it's not the case at all. They have had the text for several years.

 

[Mäster]

A HEA can be bent before assembly, so it becomes straight under load..

 

[imported_Byggaren]

Beijer has a fun text about laminated timber and I believe everything that is on the internet.....

"Laminated timber is a natural building material that has become immensely popular in recent years. And it's no wonder. Laminated timber has essentially the same load-bearing capacity as steel but weighs only half as much. It also withstands fires better than many equivalent materials, which is often reflected in insurance premiums. The image shows examples of laminated timber beams and columns."
[link]

Maybe I should add that this is not true at all. They have had the text for several years

It's partially correct. A steel beam, unprotected against fire, loses all load-bearing capacity already at +620 degrees C. A laminated timber beam chars on the surface and can hold out long after a steel beam has given up for a long time. The same applies to solid wood. If you look at a house that has burned, it's often the roof trusses (of wood) that remain + the chimney, but if it's a steel construction, it twists like cooked macaroni on the ground.
_____________________
Byggaren

 

[shelby67]

That is partially correct. A steel beam, unprotected against fire, loses all load-bearing capacity already at +620 degrees C. A glulam beam chars on the surface layer and can withstand long after a steel beam has given up long ago. The same applies to solid wood. If you look at a house that has burned, it is often the roof trusses (made of wood) that remain + the chimney, but if it's a steel construction, it winds like cooked macaroni on the ground.
_____________________
Byggaren

Macaroni, you mean like with world trade center

 

[imported_Byggaren]

Macaroni, you mean like with the world trade center

Maybe I should have used cooked spaghetti as a comparison instead?
___________________
The Builder

 

[Mäster]

Even though the house has burned down, it feels like a smaller problem that the steel beam is destroyed...

 

[shelby67]

I am prepared to agree

 

[petersk]

Now, it wasn't fire that I had in mind regarding Beijer's text.

Steel must be fire-protected to the necessary extent. For small houses, 2 layers of 13 gypsum or 15mm Knauf fireboard are sufficient. It is usually calculated that wood burns away at 0.5mm/min. An ltb 90x405 after 30 minutes of fire with three-sided fire exposure would be 60x390. Which should handle the fire load scenario. However, this is usually not a problem.