How to build a bi-fold side gate?

[nikkinik]

We are thinking of building a gate to close off access down the side of our house.  Because we purposely made this area wide we want to make sure that any gate we put in can open up so the whole width can be utilised when required.  (Photo is looking down the side of the house towards the street, the gate would be installed close to the front of the house)

The opening is roughly 2.45m and we will also require pedestrian access, so we thought of doing a double gate design with one 750mm wide single gate and the other side a bi-fold gate made up of 2x 750mm gates. Here is a rough sketch of what I have in mind (hinges are only drawn like that for ease of recognising them as hinges). Gate height 1.8m. 

 

We want to use these Gate Kits for this. 

 

as well as the ‘Rapid Fence 50x50 x1.8m flanged fence posts’ which would be secured to the concrete using chemset anchors. 

It can get quite gusty down that section (as seen this past week with the crazy wind we had!) and I’ve worked out that if the gate area was a solid (no slats or anything) it would need to withstand Wind Loads of 3.45kN and Dynamic Pressures of 0.798kPa.  Now that doesn’t mean much to me (I used an online calculator) and I have no idea how to this wind information affects my design choice.  Would bolting the posts to the concrete be sufficient? 

Also, Do I need to reinforce the hinges on the bi-fold side? The gate kit says they’re good for gates up to 1500mm which technically the two gates together would be.   I have drawn a spring loaded wheel into my design to help support the bifold - is this actually needed? 

And last question: I have searched the bunnings website high and low for a ‘thumb gate latch’ hut have found nothing.  There are some latches but they say no access from outside - that defeats the purpose of it being a pedestrian gate!

tl;dr

Questions I need answered:

1. will the rapid fence 50x50x1.8m flanged fence posts be fine to support the bi-fold design?

2. will bolting the posts to concrete be ok?

3. Will the gate kit be ok for a bi-fold design?

4. Do I need a spring load wheel for extra support?

5. Does bunnings sell pretty ‘thumb gate latches’?

Cheers!

Location: Geelong (VIC)

[Dave-1]

Afternoon @nikkinik 

I would go for a heavy duty one as it will be supporting your posts Pryda 100mm M12 Heavy Duty Bolt Down Post Anchor 

To get the gap at the bottom all I did was place a timber offcut (20mmm ish) on the base and rested my post on that. Once the post was bolted to the stirrup I tapped out the timber offcut.

Dave