Fencing with rock close to surface

CowSniffer

Hi All,

I want to fence in a sizable part of my garden, nearly 120m from one end to the other. However, my entire garden has a rock layer under the surface anywhere from 3 inches to 20 inches down. I was hoping to put up posts that would give me 4 ft above but that means I have to 2 ft down at least, so would have to go through ALOT of rock.

Any suggestions of how to get through this rock, or a way to work around it?
Are my only options hiring someone with a rock breaker?

any suggestions or ideas appreciated

Reckless Abandonment

Do you mean small rocks or a layer of hard Rock?

49801

Is it accessible to a tractor. Some fencing contractor have post drivers that have a rock breaker spike to pre bore a hole.

Otherwise it’s a mini digger with rock breaker job.

gman2k

Sounds like a rock breaker is your only option. And it's going to be expensive, as these jobs are priced on time.

LaChatteGitane

Don't know if it's a possibility, but can you make concrete footings (in a mould of timber) for your posts en attach them to said footings ?

Hocus Focus

Assuming that the posts are standard (7omm x7mm, 90mm x90mm etc), where the soil is too shallow, you could dig holes , say 12" x 12" , pour concrete into them to surface level and when set, screw down the flanged fittings that are available for erecting fenceposts on paved surfaces:
https://www.diy.com/departments/outdoor-garden/fencing/fence-post-support/DIY585883.cat#icamp=SRD_Outdoor_FencePostSupport_L4

gman2k

Hocus Focus wrote: »

Assuming that the posts are standard (7omm x7mm, 90mm x90mm etc), where the soil is too shallow, you could dig holes , say 12" x 12" , pour concrete into them to surface level and when set, screw down the flanged fittings that are available for erecting fenceposts on paved surfaces:
https://www.diy.com/departments/outdoor-garden/fencing/fence-post-support/DIY585883.cat#icamp=SRD_Outdoor_FencePostSupport_L4

The likes of that and the post above wouldn't be suitable to take a horizontal wind load on the fence.

But you could perhaps bond a concrete pad to the exposed stone layer, by drilling down into the stone say 150mm, grout in 4no 10mm threaded bars and then pour the conc pad onto these and the cleaned off stone. Then you could attach a post support to the concrete.
You would have to know what you are doing, how to ensure the bars are correctly bonded into the stone layer below etc etc

CowSniffer

gman2k wrote: »

The likes of that and the post above wouldn't be suitable to take a horizontal wind load on the fence.

But you could perhaps bond a concrete pad to the exposed stone layer, by drilling down into the stone say 150mm, grout in 4no 10mm threaded bars and then pour the conc pad onto these and the cleaned off stone. Then you could attach a post support to the concrete.
You would have to know what you are doing, how to ensure the bars are correctly bonded into the stone layer below etc etc

Thanks everyone for all the feedback. Really appreciate it.

Above is a really good idea. I need to do some test holes along the edge and get a better idea what I'm dealing with underground so I'll know if this is workable.

I had a look online about it and came across U-B type post supports (Link below). Could try one hole straight down, epoxy it in and attach the post to that. My plan with the fence was that there would be a beams running between the tops of the fences anyway so that would give some extra support as well.

Thoughts?

https://www.post-anchors.com/postanchors/post-support.html

Hocus Focus

CowSniffer wrote: »

Thanks everyone for all the feedback. Really appreciate it.

Above is a really good idea. I need to do some test holes along the edge and get a better idea what I'm dealing with underground so I'll know if this is workable.

I had a look online about it and came across U-B type post supports (Link below). Could try one hole straight down, epoxy it in and attach the post to that. My plan with the fence was that there would be a beams running between the tops of the fences anyway so that would give some extra support as well.

Thoughts?

https://www.post-anchors.com/postanchors/post-support.html

A. The supports in the link are utilised by screwing them into soil. There are supports in B&Q, in the same range as I linked to above, which you hammer in, but the problem you have is that you need to attach your supports to bedrock, hence the method I mentioned above, using a concrete footings on the rock.

B. It says on that website that the minimum order is 1500 units, I don't think you need that many. Supporting local hardware outlets is more sustainable than bringing them halfway around the world.

C. Any side loads caused by wind can be avoided by building the fence in such a way as to allow the majority of the wind to blow through. Diagonal struts at intervals might also help in this regard.

Co11ins

Is it a stock-proof fence you're looking at?

We have used Clipex stakes to fence land in the Burren. Drilled a hole in to the limestone of a slightly smaller radius than the stake and bet it in to it, very sturdy and should be there for a long, long time.

Australian company but popular here in Ireland, with a base in Ennis.