Post Anchor/Stirrup question

[reilly]

I am putting up a pergola made of old hardwood. Posts are approx 200x300x2700 (old pier pillons) and weigh about 60kgs each. There will be a deck around the pergola.

The pergola will be put up first then the deck built around it.

I will be using concrete stirrups to secure the posts to the ground. My problem is that the deck will be about 400mm above the ground level so the bottom of my post needs to be around 300mm above ground level. The longest stirrup I have found is only 600mm.

Does anyone have any suggestions/comments about sitting the stirrup in a 300x300x600 cement filled hole but only 300 of the stirrup is in the cement whilst 300 is sticking out of the top with the post on it.

[echnidna]

Build the deck frame on stumps first and then build the pergola on top of the deck frame.

[bitingmidge]

When a stirrup is 300 mm long, it's called a column!!

Why not form up the concrete to within a sensible distance of the timber?

I am assuming you are using nice structural steel purpose built to hold posts of that magnitude, not some off the shelf piece of sardine can??

Cheers,

P :D

[jaws]

When we have large timbers to go on supports or are near the coast we have them custom made and galvanised.
The ones you buy in the hardware are thin and and not well coated I have seen these post supports rust out in 4 years down the coast.
I'm sure you could find a local steel fabricator who would make what you need.
cheers
John

[reilly]

I had planned on using Pryda stirrups

http://www.pryda.com.au/catalog.php?sectionid=20&type=Post%20Anchors&conn=PAF65-90

Do you think that these will do the job ?

[jaws]

For posts the size you have I wouldn't personally use any premade post support.
I would have them custom made to suit.