New garage with more ceiling height, what about roof trusses?

[gotulwe]

Sketching a new garage and it's just as well to plan for a 2-post lift, making ceiling height important. W-trusses are naturally the best from a load-bearing perspective, but I looked at scissor trusses and modified a bit, of course making it weaker! The video makes it clear.... They span 8.4 m, thinking of a 12 m long garage. What does the knowledge here say about building a lightweight version, with plywood on both sides of the truss? And filling the truss with insulation??

 

[fribygg]

Do you have the knowledge to calculate strength or have you found any program that can calculate trusses with plywood webbing?

 

[gotulwe]

Hi Fribygg, I have some solid knowledge but in mechanics, not construction. The online program from Träguiden is good, but my idea here feels unconventional, while there are also masonite beams as lightweight alternatives which also work to reduce thermal bridges.
By the way, the video shows a tendency, material data and snow load are correct but the attachments are solid, I can't do nail/screw joints in that program. And the bending is scaled up 100 times so it's more visible 😆

 

[Karrock]

Gabbe's mountain cabin was indeed such trusses, there is a detailed construction thread somewhere around here.

 

[gotulwe]

Have continued with different roof trusses today, 3 is best and 2 is good enough, presses slightly on the walls. 1, 4, 5 no, not good. The image shows stress in the material.

 

[Unikt namn]

You don't "have" to have the same ceiling height everywhere. You can indeed have different rafters, or a ridge beam, precisely at the lifts.

 

[Karrock]

Constructors want a high utilization rate, over 90% when safety factors are included, anything else is wasteful.

 

[gotulwe]

You don't "have to" have the same ceiling height everywhere. You can have other roof trusses or a ridge beam right at the lift.

Yes, exactly, and you can combine that with the door so that the rails inward and motor opening work, so you don't have to have a folding door, for example. I don't know how to handle the ridge beam, do you have to have support columns in the middle as well? The online program protests.

 

[RoTe]

Designers want a high utilization rate, over 90% when safety factors are included, anything else is wasteful.

Exactly, it's not rocket science, many garages already exist and I haven't heard of any that have collapsed.