I am going to build a carport with a lean-to roof, area approx. 6m x 6m. The question concerns the dimensioning of the roof, the number of load-bearing beams needed, and whether roof beams will suffice, or if trusses are preferable. Snow zone 2.
One of the load-bearing beams will be attached to a storage wall. The beams will span just under 6m each and will be in laminated timber 90x405.
All dimensioning programs say that roof beams of about 6m must also be made of laminated timber, and as we know, costs can quickly escalate then.
The question is whether it is possible to use construction timber beams 45x220, if I relieve the load with a beam in the middle (so that there are 3 beams in total)?
Or would it work with lean-to roof trusses in 45x220 with a span of about 6m? It would be nice to skip the beam in the middle...
So, are trusses a stronger construction that can handle a larger span than simple lean-to roof beams?
Thank you in advance for your opinions & advice.
One of the load-bearing beams will be attached to a storage wall. The beams will span just under 6m each and will be in laminated timber 90x405.
All dimensioning programs say that roof beams of about 6m must also be made of laminated timber, and as we know, costs can quickly escalate then.
The question is whether it is possible to use construction timber beams 45x220, if I relieve the load with a beam in the middle (so that there are 3 beams in total)?
Or would it work with lean-to roof trusses in 45x220 with a span of about 6m? It would be nice to skip the beam in the middle...
So, are trusses a stronger construction that can handle a larger span than simple lean-to roof beams?
Thank you in advance for your opinions & advice.
Roof trusses are usually made without glulam for much longer spans than 6m. So it should be possible. But exactly how they should be designed needs to be calculated by an engineer. Alternatively, you can buy them ready-made from a truss factory, which also performs the calculations.
With a central support beam, you only have a 3 m span. Regular K-grade timber handles that just fine.
(I have a woodshed with a sloped roof, about 10 degrees, 6 m span, and 7 m long. It has 45x195 cc 120 cm. It has survived somewhere between 25-35 years now. Of course, it's probably not entirely safe to go in there during winter when there's a lot of wet snow on the roof, but it gives some perspective on structural design.)
(I have a woodshed with a sloped roof, about 10 degrees, 6 m span, and 7 m long. It has 45x195 cc 120 cm. It has survived somewhere between 25-35 years now. Of course, it's probably not entirely safe to go in there during winter when there's a lot of wet snow on the roof, but it gives some perspective on structural design.)
Many thanks for all the responses.
I have now measured more accurately - the span (roof beams) will be 5.3 m, the width (support beams) 5.8 m.
What do you think about having closer roof beams (cc 60), in k-virke dimension 45x220? Wouldn't that result in a stronger construction than the same beams with cc 120?
I can check roof trusses with an engineer, but the roof slope will be just under 10 degrees, I believe no one will want to calculate on a roof with a pitch under 14 degrees..?
I have now measured more accurately - the span (roof beams) will be 5.3 m, the width (support beams) 5.8 m.
What do you think about having closer roof beams (cc 60), in k-virke dimension 45x220? Wouldn't that result in a stronger construction than the same beams with cc 120?
I can check roof trusses with an engineer, but the roof slope will be just under 10 degrees, I believe no one will want to calculate on a roof with a pitch under 14 degrees..?
Roof beams in one bay.
Roof beams in two bays.
Maybe if you screw-glue 45x70 on top of 45x220 and use cc60 it might work, but it's just my guess. I haven’t calculated anything...
Note, the links from Träguiden apply to lightweight roofs, i.e., metal/plastic.
Roof beams in two bays.
Maybe if you screw-glue 45x70 on top of 45x220 and use cc60 it might work, but it's just my guess. I haven’t calculated anything...
Note, the links from Träguiden apply to lightweight roofs, i.e., metal/plastic.