I want to create an opening in an exterior wall of a house with a flat roof. I want either folding doors or sliding doors. The house is built on a rock with a solid and extra-large concrete foundation (crawl space).
Area: Stockholm
Roof: Felt with a normal ceiling.
Roof slope: 0-1 degrees (flat)
There used to be a good tool to calculate glulam dimensions and specify flat roofs, but I can't find that tool anymore. Also, I remember that glulam probably wouldn't work since it required a height of over 60 cm.
I have a limited height to work with. The beam can be about 25-30 cm high.
Which steel beams (IPE, HEA, HEB, etc.) and dimensions can I use?
It would be so darn nice if someone could calculate or describe how I calculate.
At Byggbeskrivningar.se, I can calculate which glulam beams I need, but it's not possible to calculate for flat roofs or openings over m (max is 5m). Additionally, I don't know if I should use the size of the house body or the roof when calculating.
Self-weight of outer roof:
0.55 kN/m2 - Roof with felt, insulation, and internal cladding
Self-weight of inner roof:
0.45 kN/m2 - Normal inner roof (for example, with single/double gypsum board)
I would never use building scripts or any similar calculation app myself. You never know what assumptions are hidden. Are the trusses truss trusses without support in the middle?
If the beam cannot be higher than 300 mm, glulam will not work. The smallest glulam beam I can imagine is 215x450 mm. It will have to be steel instead, perhaps HEA 260. Considering how you plan to use the opening, the deflection should be limited more than usual, which leads to a somewhat stronger dimension.
I usually don't estimate in situations like these. I calculate it using elasticity theory. The dimensions become large because the roof loads are so big due to the span. If you want sliding doors, it requires a very low deflection. You can replace an HEA 260 with an IPE 330. If you reduce the opening size to 4.8 meters, an HEA 220 or IPE 270 will suffice.
