We're in the process of enclosing our veranda, which will result in the exterior wall that housed the front door being opened up from 1m to nearly 4m. How do I calculate the size of the beam? What information is needed?
What you need to know is the load per meter length that the beam needs to support. It can, however, be a bit complicated to determine that information. Important parameters are the construction of the house (year of construction can be important), size. Whether the opening is in a gable wall or a long side wall is usually very important. If you want help here on the forum, drawings are absolutely crucial. Plans and sections. A 4-meter opening will likely require a fairly substantial beam.
Year built 1944
Size 12.5x8.5m
1 ½ story split-level house with a hipped roof
The opening is in the middle of a long side wall
The trusses are 180x65mm and are spaced at cc850
There is a dormer directly above this wall so the trusses are about 160-170 cm from the sides of the door.
This is the white door at the top of the attached drawing.
More questions?
Size 12.5x8.5m
1 ½ story split-level house with a hipped roof
The opening is in the middle of a long side wall
The trusses are 180x65mm and are spaced at cc850
There is a dormer directly above this wall so the trusses are about 160-170 cm from the sides of the door.
This is the white door at the top of the attached drawing.
More questions?
Where is the house located? The information is needed to assess the size of the snow loads.
Southern ÖstergötlandJ justusandersson said:
I'll get back to you later during the day/evening. Typical 1940s functionalism. The framework could be from Svenska Trähus in Tranås. Wooden framework with plaster on the outside (at least from the beginning).
As far as I know, there has always been wood paneling on the house.
OK. No disadvantage in this case.
Roughly calculated, the beam needs to be around 90x495 mm. If you choose thicker beams, you can reduce the height. The minimum option is 215x360 mm. These are estimates based on certain assumptions. You need access to accurate drawings or (preferably) see the house in reality to make more precise calculations. You must engage a structural engineer for the task. The measure also requires a building notification.
So strong even though there are no roof trusses directly above?
As I wrote, it is an approximation. Probably a precise calculation will lead to a slightly smaller dimension. However, this requires data with significantly higher accuracy. Still, expect it to be a fairly substantial beam.
Does it matter, either way, that the veranda roof is supported by beams/studs of 75x230 resting on the same wall? The idea is to either place the beams on these beams or right next to them.
It certainly matters, but I need to see a section drawing to be able to say much more.
Unfortunately, there are no drawings.
I am convinced that there are blueprints for this house. Have you checked with the municipality? I suspect it is a form of standard house. It's just a matter of finding out who the manufacturer was.