How to calculate glulam load-bearing wall

[jonaslatt]

I am going to demolish a load-bearing wall in my house. The wall is perpendicular to the gable. The wall is about 3 meters long. And when I checked the attic, the glulam beam needs to be about 4 meters long.

I have a regular roof, not flat.

Is there any standard I can use for calculations?

 

[Janus82]

I think I might misunderstand you, but from your description, it sounds like the wall you want to tear down runs parallel to the gable, is that correct? Normally, such walls are not load-bearing; instead, load-bearing walls tend to run perpendicular to the gable (and the roof trusses).

Do you have any drawings or other images you can upload?

 

[jonaslatt]

Of course, it is as you describe. Thanks, I have changed the text now. It goes perpendicular to the gable.

 

[mdab]

How wide is the house?

 

[nimhed]

How wide is the house?

What are you going to do with that information?

 

[jonaslatt]

About 7-8 meters. Old wooden house with additional brick cladding if it matters.

 

[mdab]

You need the width to calculate what load the glulam beam will carry. I can look into this when I have a little free time.

 

[jonaslatt]

I was told today that it should be 10 cm wide, 25 cm high, and four meters long. Do these measurements seem correct? My wall that should come down is 10 cm wide.

 

[mdab]

Hello again, Glulam 90x315 or alternatively 115x270 I would choose
100x250 is a bit flimsy

 

[jonaslatt]

Oh, so the person who calculated for me had worked at Moelven Töreboda, which makes these beams. Is he off track?

 

[mdab]

I did calculate based on snow zone 2, and in some parts of Västra Götaland it's snow zone 1.5. So if you live in snow zone 1.5, then 100x250 is completely fine! You can check which zone you live in by looking at the table here: http://www.svedentra.se/Gismo/files/1289/snözoner.pdf However, isn't 100x250 a rather unusual dimension?

 

[jonaslatt]

I really know nothing about this and asked for help here but got no responses at first, so I talked to a friend whose father has worked there in Töreboda. And he said that I needed those measurements. I checked the table you attached and apparently, I'm in snow zone 2.5 living in Skövde. The roof has a slope of 27 degrees.

So I feel a bit lost now. The wall is 2800mm, but as mentioned, I need to have a beam of 4000mm to work with the trusses.

 

[mdab]

I'm not following why you need to have a beam that's much longer than your wall? It's usually done according to the image below. And if you only have a 2.8m span, then a 100x250 works even in snow zone 2.5, but with a 4-meter span it's too weak. If you're going to remove the entire wall and that's why you can't recess it according to the image, then you need a column to support instead...

 

[jonaslatt]

I will place the beam over the rafters in the attic. And therefore I will not have a vertical beam as you show in the picture.

 

[mdab]

Are you going to have columns at the ends of the beam then? Or what supports the beam? You can't just lay the beam over the rafters. That provides no load-bearing capacity at all, rather the opposite.