Pergola dilemma

[JP_]

OK, as mentioned, building a pergola, of sorts, with purpose to provide shelter for dad's 80th.
So I have the timber. The posts are 2.7m.

Now, I was going to just build it freestanding, as might move it later, but at 2.7m it is bloody tall and just going to make it harder to build. So maybe I should bite the bullet and bury the posts in the ground about 40cm deep so it is a more sensible 2.3m tall. Or do I just build big as it is temporary and will come down anyway? I don't have the corner supports yet, so burying it is actually starting to look more like the only option.

Not sure where the posts will go at the moment ... got some concrete I don't plan to move in this heat, and need to keep the path clear ...

The width is 2.7m, I think I can have the posts set in 60cm from each end and have plenty of space for tables, paths, and avoid breaking concrete. It is "the wrong way round" for a pergola, in that I am having 2 2.7m widths across the posts, then 3.6m lengths on top, rather than the traditional shorter posts on top.

 

[JP_]

Might just cut 30cm off and have it free standing...

 

[JP_]

Well, that was not very hard. Those big cork screws really do work!

 

[JP_]

 

[JP_]

update

 

[sxturbo]

Looks good

 

[mynameistakenalready]

That looks great, would you recommend that cork screw auger over a traditional post digger?

 

[JP_]

Finished it. Dragon wind chime added, wife is out buying oriental style lanterns.
Actually, not completely finished, still need to fix the two outside rafters

 

[John D v2.0]

Looks good, and it's also good that you buried the posts as it would have been extremely rickety otherwise!

 

[JP_]

I was going to put in some corner braces if freestanding. A bit worried about long-term post rot, but they are pressure treated, so I should have a good 10 years out of them?
If they rot I will probably support the roof and cut the legs, then put in some steel post supports - already planning for failure!

 

[John D v2.0]

Thanks for the reply, I'm certainly no expert!
Corner braces can help especially if they're looking enough. Last weekend i built one out of 3mx70x45 in 500mm deep post holes, with 8 no 600mm corner braces.
It was all over the place when I'd only filled the holes around 200mm, but once I got them filled to the top it was ok. I think this is just because being braced at both ends is much better than one or the other.
Anyway yours looks nice, ours is just to hold up tomatoes and a grape vine so is not aesthetic at all!

 

[John D v2.0]

Sorry missed your rot question, they will rot quicker than that if they're on the ground, but apparently charring the outside at ground level with a blow lamp can extend the life a lot.

 

[JohnD]

I was going to put in some corner braces if freestanding. A bit worried about long-term post rot, but they are pressure treated, so I should have a good 10 years out of them?
If they rot I will probably support the roof and cut the legs, then put in some steel post supports - already planning for failure!

the roof provides a lot of stiffening so you should not need corner braces. unlike a fence, a pergola or shed is less inclined to blow over.

though a diagonal at the top quarter improves the appearance IMO and reduces stress on the corner fixings

Wood buried in the ground will rot quite quickly.

If you have not footed them in concrete, when they snap in high winds it will be fairly easy for you to cut them off ten inches above ground level and put in a concrete spur that you can bolt the remaining leg to.

though it would have been easier to do that in the first place.