# Forum Home Renovation Sub Flooring  Setting posts on stirrups

## bitpimp

Hi all,  
I'm setting 2 100x100 treated pine posts on stirrups into concrete, but wondering if anyone can throw some advice to the first timer.  
The structure is going to be a fernery: _a mini pergola attached to the side of the house (_2 posts, 1 bearer and joists going to the house with a shade cloth on top).   
I used 450mm stirrups, concreted to about half way (height wise). It's been a few days now so I've placed the posts in the stirrups and bolted them when i noticed they have a bit of wobble in them if i wiggle the post with my hand.  
How much wobble is expected normally?  
Whilst posts aren't braced to the bearer yet and there is no attachment to the house should there be any wobble ? Surely some but i dont want to proceed if i goofed something up majorly.  :Doh:  
Right now im not sure if i should wait longer and then try put the bearer up and attach it to the house..  
I used premixed concrete mix but not rapid-set, however i mixed it in the hole by mistake so I'm sure the mix isn't uniform in terms of water vs the rest of the bag content (no idea what the implications are, take longer to set?).  
Next mistake was not getting enough concrete (hence concreted to half height) so basically it was done in multiple stages (i guess the possibility of a poorer bond between lower part of the concrete footing and higher part would arise).  
For concreting the top part i used formwork so i didnt need as much as i dug the holes a bit wide (shovel). Also i mixed in outside the hole this time.   
Are all these important factors that are against me and that i cant correct any more now or am i worrying needlessly ?

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## UteMad

Are you saying the stirrups are moving inside the footing????? or are you saying the posts are moving when bolted to the stirrup??? 
if the posts move thats normal you have heaps of leverage versus the amount bolted.. if its the stirrup moving in the concrete then the concrete wasn't packed tight around the stirrup or was moved to soon 
cheers utemad

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## bitpimp

Thanks for a quick response utemad! 
That's a good question, but now that you mention it im too afraid too give it too much leverage to find out if its the stirrups or posts, maybe i will give it a couple of days to be sure and give it a bit more force to see if the stirrup moves rather than the post...

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## chuth77

What size are your footings? 
When you say you put them in 1/2 way...What do you mean? 
Are they high winder stirrups or basic post stirrups? 
How far off finished ground level if the bottom of the stirrup?

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## bitpimp

Footings were roughly (pick & shovel dug) are around 300 or 400 wide or there about and 500 to 600 deep. 
Half way meant that the long 450mm stirrup was half way covered with concrete so there is a good 200-300mm from the concrete to the bottom of the stirrup. 
Stirrups are pryda 'full stirrup posts' http://www.pryda.com.au/catalog.php?...&conn=PAF65-90 
I'm hoping once the distance from top of the concrete to the bottom of the stirrup decreases to around 100mm it will feel more solid. 
ps. Went outside and had another feel without being too rough at this stage, the stirrup doesnt wobble unless force is applied to the post above it, 'feels' like the stirrup is flexing/bending though rather than just plain swinging in the concrete but its hard to say without getting rougher... the concrete around the stirrup which touches it doesn't move/form a larger openning so perhaps its just the perception due to leverage of the post as UteMad mentioned....

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## bitpimp

Looks like my reply didnt make it yet as i posted a link to pryda site ?
anyhow to cut to the chase... 
Using full stirrup, by half way i meant the concrete level to bottom of the stirrup is about half way of the 450mm stirrup (20-25cm) so a fair bit... 
As i said i topped the concrete off separately on another day after i got more concrete and now the distance is about 15cm between the stirrup and concrete... 
It's been a day since the 'top up' and if i push the stirrup itself it doesnt move, if i use even a little bit of the post to leverage it then the pole moves, and the stirrup feels like it's flexing (the leg) but it doesnt feel like its moving in the concrete. The concrete is right against the stirrup and i dont see any openings in around the leg of the stirrup... 
i think its like UteMad said just the posts moving... (hope im not wrong  :Sneaktongue: ) 
Just while we're on this...what's the recommended distance from stirrup to concrete? 10cm or there abouts? 
Also for the future... mixing cement (non rapid stuff) in a hole, is that a no no?  
I got a mixing tray from bunnings yesterday so i used that and it looked way better when i was topping up the footings...just looked like proper concrete when i was shovelling it in...  
Also make a formwork helped as its neat and i didnt need to use so much more concrete when filling a much wider hole.

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## chuth77

Your description is a little confusing.. Can you take a photo? 
The finished concrete level and base of the stirrup should be a minium of 50mm... The closer you are to the 50, the more of the stirrup is in concrete obviosuly, so it's nice and strong... 
By the sounds of it, you did the footing in two sections? How are they tied together? How thick was the top section?

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## bitpimp

Will see if i can organize a photo when the daylight's back... 
The footing is in two sections... Top section is concrete resting on the lower hardened concrete with a stirrup through both sections as initially half of stirrup was covered in concrete and now only about a quarter is sticking out (150mm or so). I can try and get the top of the concrete higher still so its closer to 50mm from there to stirrup base as you mention... 
Top section at the moment should be about 100-150 from memory...

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## 2x4

It's good fun building decks for your own use. Will be nice to kick back and have a beer when finished and admire your work. 
There is alot of info on footing sizes , timber sizes etc to use floating around on this forum, and the google thing is also very good 
Typically post hole depths vary between 600-900mm in depth, and 350-650mm in diameter. the stirrup should have a min. of 100mm of concrete underneath(to stop it punching through the bottom) and have 75mm clearannce to the timber post (termite inspection). 
Correct mixing of the concrete is an important factor. What hight will your deck be?
Deck size? 
The shade cloth will want to pull your posts around a bit in a strong wind.

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## UteMad

The only part that gets me lost is.. And i get the 400mm long leg half set in which is fine.. If you attach a post to the shoe and bolt it then the post will wobble due to its length and the amount of leverage the post has.. You cant reley on post shoes to brace a structure just control upload and download so if you structure is correctly built and braced then you have no wobble.. the way the pryda shoe you have is built is the non welded idea where the post is rolled onto the U bracket .. there will be flex in this too with a post as a lever.. 
have i got it or am i missing something?? 
cheers utemad

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## bitpimp

Here is some very average pictures... Sorry its wet and miserable in melbourne now and the photos ruined due to reflection but at least its an overview... 
This thing isn't a deck nor will it have sail shades which would be subject to strong up/down forces, it's more like a mini pergola (no roof) but it will have shade cloth material over it to provide partial sun protection to tree ferns below. So the top is hollow.
Basically 2 posts in stirrups and a bearer running parallel to the house with joists going to the the house and material (70% uv shade) on top. 
One thing i'm not sure about is the 'punching through' factor that 2x4 mentioned.. I was so paranoid about getting posts/stirrups level that i didnt pay too much attention to that, the stirrup has a plate at the bottom so hopefully that will help there... Yeah i know the stirrups dont need to be level as long as the tops even out but oh well.... You need to have a go at something before you can see how differently you can do it next time  :Roll Eyes (Sarcastic):

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## chuth77

Top of footing looks a bit small, but how deep are they, and what width are they?

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## bitpimp

Approximate schematic of the footing, its still pouring outside so i havent measured exactly.
The small looking footing at the top is concreted on top of larger (first phase) one, I was going to fill around the small one with soil once done...

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