Concrete post depth advice

[chris29]

Hi all,

I'm looking to replace my rotten timber fence with concrete posts/gravel boards + some close board/feather edge panels.

I'm looking to put in a 6' total height fence, and I've found this site which has 7'9" posts, https://www.garden-fence-panels.co....-length-7ft-9-for-overall-fence-height-6-foot

Their site is suggesting 1' 9" is enough of a depth to set the posts in. Other places I've read around online seem to suggest 2' for a 6' height fence is better. I won't be able to get 2' depth for all posts due to some drains running beneath the areas I'll be digging, but I wanted to get some thoughts from more experienced people. I've put plenty of timber fence posts up in the past, but I'm slightly concerned about concrete + the weight of them as I've not installed any before. it's a 23m length - and some parts of it are fairly exposed - around feb we do get some fairly strong gusts of wind where I live.

Similarly, this site sells some post mix (which seems to be for metal/timber posts, rather than concrete) - are the various postcrete / post fix bags good enough for concrete posts? I was thinking of using 2 bags per post, ideally.

Thanks for any thoughts/advice in advance!

 

[jj4091]

Did ours recently with similar dimensions. All OK, would recommend using Postcrete though it makes the job so much easier

 

[HERTS P&D]

I used 9' post on our fence, neighbours fences fell down in high winds. They all asked me why mind didn't, I told them that was because I fitted it.

Andy

 

[aveatry]

If you are digging out the old concrete from the wooden posts then you may end up with a bigger hole than you think and so perhaps need more than two bags of postcrete per post. See what others think

 

[cdbe]

You need to dig your holes and assess the ground before you decide.

 

[freddiemercurystwin]

Yep surprising sometimes how much post holes require, you can always return any unused bags.

 

[chris29]

Thanks all

I will only have to dig one post foundation out, the rest are on different centres (thankfully). The ground is easily accessible apart from 2 (one near drain services, so I think I'll only be able to get about a foot and a half - I plan to increase the diameter of the hole I dig and pour in plenty of concrete/postcrete for this post.


am I right in thinking that 2' would be the recommended approach rather than 1' 9" that the above website recommends then?

 

[JohnD]

Ordinary concrete is cheaper and stronger (though not so fast to set).

If you are using concrete gravel boards, you can sink them into the ground a little, and the concrete at the post, and they can add rigidity and wind resistance. The 12" boards are better for this (though I find them very heavy)

You will need to provide separate hedgehog highways.