I have two American porches on my house. One in front of the front of the house, and one in front of the extension. In front of the extension, the deck continues to a part that is not under the roof. Kind of like a sun deck. But we've realized that we'd love to build a cozy pergola here instead.
But I have some problems. The pergola width is 6000 mm, and I'd ideally like to only have two posts as shown in the drawing. The post on the right already exists and holds the roof over the porch. To clarify, everything already exists in the pictures except for the post on the left in the image, as well as all the timber in yellow wood color.
Design-wise, it would be best if I continued with the same type of laminated beam that is under the porch roof, which is 90x180. But the dimensioning programs I've tested online say I need at least 90x415, I believe it was.
1) So my question is simply this. Does anyone know if it would be possible to have a laminated beam that is 6 meters with a dimension like 90x180, or is that too weak? It would be a pergola, no roof, so no snow loads.
2) Does anyone know how I can get hold of the post to the left in the image? The other posts are 125x125, so it must be the same for design reasons. Do you think they are pressure treated? (they are painted right now)
3) I was thinking that the roof rafters should have a dimension like 45x170, yay or nay? bigger or smaller?
