Dimensioning glulam beam

[GDS Johan]

Hello
I am planning to extend the house at an angle and need to support the load-bearing wall with a glulam beam.

I am using the calculation program on Moelven's website, http://www.iat.inadire.se/WebLagerbalk/Lagerbalk.aspx

The problem is that I don't know what self-weight for the roof structure should be entered?
In the model, for example, there is 0.90 kN/m² for "Concrete roof tiles / insulation / interior lining"

We have a single-storey Älvsbyhus, does anyone know what the self-weight is for this type of roof construction?

Here's the plan
Hole in load-bearing long side: 5130 (hole in the middle of the long side at an angle)
House's short side: 8320 (load-bearing interior walls are missing)

Best regards
Johan

 

[GDS Johan]

Any general weight for single-story houses?

 

[anaitis]

0.90 kN/m² is an excellent value to work with.

 

[GDS Johan]

OK, that sounds good.
In the calculation tool, it says that I can choose a 140x405 beam, and that I would then get 19mm deflection under service load. Is 19mm OK for a free opening in the wall during an extension in an angle? Is it visible in practice?

Best regards,
Johan

 

[Enk Projektet]

Hi

Does the beam have to be visible? Otherwise, it might be cheaper and smaller with a steel beam like H.
Regarding visibility, it could be noticeable if it's not placed high up.

 

[MathiasS]

Everything has been discussed before on Byggahus....

http://www.byggahus.se/forum/byggmaterial-byggteknik/41757-balk-vilket-material.html

 

[GDS Johan]

Read that thread now, and steel seems interesting...
Can anyone link to a calculation model for steel beams?
Suitable place to buy steel beams?

Regards
Johan

 

[anaitis]

OK, that sounds good.
In the calculation spinner, it says I can select a 140x405 beam and that I will then get a 19mm deflection under service load. Is 19mm OK for a free opening in the wall for an extension at a right angle? Is it noticeable in practice?

Best regards,
Johan

Often it is considered a bit too much deflection. 1/400th of the length is a common measure.
In your case, that corresponds to 12 mm. I would go up a dimension.