Building a raised gazebo?

[MushCreek]

I'm planning to build a free-standing porch in our back yard (like a gazebo). due to the lay of the land, I will be building it pretty high off the ground, about 10' off the ground on the low side. The question I have is- How do I attach the upper posts to the lower ones? I've always built free-standing structures with one piece posts that go all the way to the ground, but this building will be too high. I would need 20' 6X6's. Even if I could find them, they would be quite heavy. What I'd like to do is build the deck assembly, then build the screened-in porch on top of it, but I don't know how you fasten the posts. A regular framed wall has a bottom plate to attach it, but this is more post-and beam. I know both levels need good diagonal bracing to keep it solid. Any thoughts?

[flyingvan]

How about poles instead of 6x6's?

[Don_P]

Saw some 24' PT 8x8's come in the other day $175/ea.
I've installed a knife plate in the notch on the lower post, notch the decking to allow the knife plate to project up and then slot and inserted  the knife plate into the upper post. Bolt, or steel dowel pin and plug if it needs to be hidden.

[MushCreek]

Knife plate? Is that something they would sell with the other metal connectors, such as Simpson? I think I would cut away the decking so the upper posts sat directly on top of the lower posts. Otherwise, there would be heck to pay if I wanted to remove/replace that particular piece of decking at some point. I'd be OK with metal plates on the outside of the posts, if it would be strong enough and pass inspection. I like the look of painted metal plates with massive bolts. I'd like to avoid a solution that required engineering, though.

I'm afraid that full-length posts or 8X8's would require much more equipment to raise. It would take a big crane, since the porch is well behind the house, and they wouldn't be able to drive to it, so they'd have to reach over everything.

[Don_P]

A knife plate is a piece of steel or SS plate hidden in the posts but if you don't mind exposed connectors bolting a plate or even strap on the outside is fine. These are resisting uplift only, you are picking up lateral strength some other way. Technically you are already in an engineering situation so it is up to the building dept's discretion if or when to light up your life. I've lifted far heavier with a braced scaffold tower and some thinking so don't reject all options out of hand. Cathedrals were built without cranes