Hello all-knowing forum,
It seems quite difficult to get hold of glulam at the moment, so I'm sketching alternatives for our extension. Therefore, I'm trying to find out what kind of steel beam I need instead of a 90x450 glulam beam at the ridge of an extension, 12 meters long. It spans freely 7.2 meters from one side before being supported by a column, and then it spans another 4 meters. According to the calculation tools by Svenskt Trä, the support reaction is 19kn on the outer wall and 48kn on the column. 24mm deformation. I would be enormously grateful for help!!
Best regards, Mikael
It seems quite difficult to get hold of glulam at the moment, so I'm sketching alternatives for our extension. Therefore, I'm trying to find out what kind of steel beam I need instead of a 90x450 glulam beam at the ridge of an extension, 12 meters long. It spans freely 7.2 meters from one side before being supported by a column, and then it spans another 4 meters. According to the calculation tools by Svenskt Trä, the support reaction is 19kn on the outer wall and 48kn on the column. 24mm deformation. I would be enormously grateful for help!!
Best regards, Mikael
Comparing the bending stiffness, it means at least an HEA220.
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· Västerbottens län
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Is it easier to get hold of an iron beam than wood?
There is a shortage of most things.
Protte
There is a shortage of most things.
Protte
A 12 m long HEA220 weighs about 600 kg and costs approximately 15000 SEK. A centrally placed support as eccentric as you are considering is not ideal. You might want to reconsider the design. If you share your drawings in the thread, you can surely receive valuable feedback.
I don't know if there are any specific fire protection requirements in your case, but glulam is often considered safer from a fire perspective since it chars on the surface but retains a load-bearing core when the steel beam has become soft and buckled in the heat. Otherwise, it might be possible to make a nailed truss beam out of wood or search online for information about so-called HB-beams (HB I believe stands for Hilding Brosenius).
The fire protection of the steel is easily resolved with panels or painting. Fire protection requirements are not difficult to meet in small houses.
Thank you all for your responses! Yes, it seems it will be a slightly larger piece, but depending on how the rest of this build goes, it might still be worth it. I will need help from a crane truck to assemble the house, so it won't make a huge difference to how it would otherwise have been. The glulam beam would have weighed about 300 kg and cost nearly the same as the steel beam because it seems that manufacturers have had difficulty delivering...
Bossespecial, I finally found a table of length between supports, load in kn/m, and deflection based on max load:
https://abrahamssonsjarn.se/app/upl...FjABegQIJBAC&usg=AOvVaw3R5YcZQiKIi3B6ciSuMj5Z
I think and hope that I understand correctly that an IPE 270 would also be sufficient. It’s also a sturdy piece but slightly lighter than HEA 220.
I will try to upload a picture of the floor plan later, justusandersson. I agree that it would be more sensible to place the central pillar in the middle, but the house was planned when glulam was readily available. Simply put, the pillar is hidden in a wall that from the gable view provides space for a room that has just the necessary dimensions to constitute an accessible double bedroom, which was a requirement. If you move the pillar towards the other gable, it ends up in the middle of a hallway. Not optimal. Initially, we had designed the room at the other end to be lowered by half a meter, and I had also designed it with a pillar standing precisely at the level difference, as part of the railing. It was rejected by the building permit officer for accessibility reasons.
Bossespecial, I finally found a table of length between supports, load in kn/m, and deflection based on max load:
https://abrahamssonsjarn.se/app/upl...FjABegQIJBAC&usg=AOvVaw3R5YcZQiKIi3B6ciSuMj5Z
I think and hope that I understand correctly that an IPE 270 would also be sufficient. It’s also a sturdy piece but slightly lighter than HEA 220.
I will try to upload a picture of the floor plan later, justusandersson. I agree that it would be more sensible to place the central pillar in the middle, but the house was planned when glulam was readily available. Simply put, the pillar is hidden in a wall that from the gable view provides space for a room that has just the necessary dimensions to constitute an accessible double bedroom, which was a requirement. If you move the pillar towards the other gable, it ends up in the middle of a hallway. Not optimal. Initially, we had designed the room at the other end to be lowered by half a meter, and I had also designed it with a pillar standing precisely at the level difference, as part of the railing. It was rejected by the building permit officer for accessibility reasons.
An IPE270 is as rigid as a HEA220, but with slightly lower bending resistance. The drawback of an IPE is that it is very prone to buckling, so one must choose solutions that can brace the beam. The placement of the column works, but it's on the borderline. If you have a continuous beam with one long and one short span, uplift forces may occur at the outer end of the short span. Truss work in wood as an alternative I do not find applicable in this case.
Thank you so much for the help! The beam will be stabilized with the roof purlins and anchored to the columns, it won't go anywhere... There will also be a tie beam that connects the roof purlins a bit further down. Letting go of the trussB bossespecial said:
Regards Mikael