Fence post depth advice

17 Oct 2017
Reaction score
United Kingdom
I'm looking for advice please. I've done many fences over the years and never had a single problem. Until now.
For a standard fence panel of 5ft 10in high, you use a post of 7ft 10in, if no gravel board is used then the remaining 2ft of post goes in the ground. No problem there. But what about when you use a gravel board?

The industry standard for fence post depth varies between 1/3 of post or between 17in and 24in in the ground.
Posts are sold in 3m (9ft 10in), 2.4m (7ft 10in), 1.8m (5ft 10in).

Here is my issue with current fence.
the posts are 2.4m (7ft 10in)
The panels are 1.8m (5ft 10in)
The gravel board is 6in
So adding the panel and the gravel board together gives a total left to go in the ground of 1ft 6in. How can you possibly put minimum of 2ft in the ground? The only way I can see is if a 3m (9ft 10in) post was used. Meaning 3ft 4in in the ground. Am Iissimg something?
Sponsored Links
you can buy 9ft posts and normally a 12" gravel board would be used but in this instance you need to go a bit deeper on the post
I've spoken to my diy merchants and he has said that in all the people he knows who fit fencing, he's never sold a 9ft post. Always 7ft10. It's baffling me.
Sponsored Links
most people probably don't go over 6ft so either have a 6ft panel and no gravel board or a 5ft panel and 12" gravel board which is what I have at the front so as not to cause probs with neighbours

Cheap place that too
Ive always done 18 to 20in in the ground as that's what I was told when I first started out. Done many, many fences with wooden posts and gravelboards over the years and never had a problem. But this is the first time I've used concrete posts.
You haven't mentioned which types of post, but on the assumption that it's concrete, then they can be cut with an angle grinder if you don't want to dig the hole deeper. A stone blade will go through the metal as well as the concrete, but if you swap to a steel blade, then it'll cut through the rebar much quicker.
Thanks for that. It's a fence I put up about 2 months ago. Have had two major storms. Since then and both times. It's. Blown down in different parts. This last storm last week two of the posts actually broke. Steel bars ok but the concrete snapped all the way round 3 posts
That suggests cheap posts, so I'd find a better quality ones next time, or go for wooden slotted posts that will have a bit more flex. The winds are only going to get stronger in years to come, so I suspect there'll be a few rethinks on how we handle these situations. Jacksons do a a 120x124 slotted post, and that'd be easier to handle than a larger concrete post, and I haven't had any issues with those.
It's the first and last time I've used concrete posts. Never a single problem with wooden ones. And a lot easier to handle.

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links