I am going to build a mezzanine floor measuring 9x7 meters and plan to use a steel beam of 3.5 meters and then use "regular" timber for the rest. Who on this wonderful forum can help me determine the correct dimension of the beam?
-Is the joist 9 or 7m wide, i.e., what is the total span width? The length is not as interesting (since we already know the length of the beam).
-What does the construction of the intermediate floor look like, what is it made of (to estimate the dead weight)?
-Is there regular living space above, or should any extraordinary loads be considered?
-What is more important, to have a low-beam or a lightweight beam?
It is always best to have a sketch of the load case to avoid misunderstandings.
Read my question today and barely understood myself what I meant
Making a new attempt:
Above there will be a living room with a fireplace, but not a monster, rather quite simple and light. Bedroom, small toilet.
I just noticed in the picture that the beam isn't on the wall, but it will be later and will also rest on a standing beam and extra reinforcement in the slab.
The garage will be built in leca.
Hope this helps you understand.
I reserve the right for any misunderstandings.
The load case I calculated looks as follows:
Span: 9m, simply supported beam with evenly distributed load.
Load: 250kg/m2
Approved deflection at the center of the beam: 2cm
This results in a required moment of inertia of approximately 17500 cm4
Suggestions for beams, (weight):
HEA 300 (800kg)
HEB 280 (930kg)
IPE 400 (600kg)
Of the above, IPE 400 provides the least deflection.
Thanks Gabbe1, what do you think, will it sag or become bouncy? looking for a rigid floor. I have a friend who built with kerto and he has rattling in the fine glasses when he walks on the upper floor
Just don't forget that where the forces from the beam's support are to be absorbed, and pillars or similar that pass the forces downward, as well as how they are then managed by the foundation and ground, must also be given some consideration.
All this should withstand a few extra tons.
How many kN are there in support forces Gabbe1?
I calculate it to be around 80kN, that is approximately 8 tons.
The floor is 9x7m, the load is 250kg/m2, and half of the load is on the beam. If you disregard the weight of the beam itself and only consider the load on the floor joists, it amounts to 38.7 kN in each column (2 columns).
If TS is open to having an extra pillar in the middle of the beam (should be in the middle of the garage if I understood correctly), then you can significantly reduce the beam size and it provides less deflection in the floor structure.
If the original poster is willing to have an extra pillar in the middle of the beam (it should be in the middle of the garage if I understood correctly), then one can significantly reduce the beam size and there will be less deflection in the joist.
It's precisely that pillar I want to avoid, and I have room in the ceiling; 3m minus 400 gives me 260 as the minimum ceiling height I can manage with that.
Is the wall between the garage and the storage room load-bearing? If so, there will be significantly less load on the steel beam. On the other hand, if it is not load-bearing, it will be difficult to manage the floor joists in the section that becomes 5.5 m.
