Can I use ground screws for a fence post?

[hambly]

Hi All,

Just moved into a house that has an asbestos fence to the side boundaries. Removal and replacement looks like it's going to be a costly endeavour, and we don't think the neighbours are interested in sharing the load, so I'm looking at building a new fence/privacy screen in front of the existing fence, for both aesthetics and a bit of extra privacy (I'm planning on it being closer to 2m rather than the current 1.8m).

To maximise garden space I was hoping to build as close to the current asbestos fence as possible. I'm not keen on the idea of digging out holes for a fence post so close to the current asbestos fence. Just doesn't seem like a great idea to me to disturb the ground lots near the asbestos. Would ground screws, such as these https://www.bunnings.com.au/otter-690-x-90mm-ground-screw-stirrup_p0084143?store=2260&gad_source=1&g... provide a suitable alternative? Seems like it would disturb the ground less.

In my head though I'm struggling to see how a 1.8-2m fence post sits on there and feels stable in the same way concreting into the ground would? I'm planning on either having simple 1.8m wide composite panels between the posts, or installing a proper composite panel fence. I'm also not convinced I'd have the space needed to manoeuvre the screws if I'm installing them tight to the current fence.

Has anyone used ground screws for a similar project? Do they feel stable? Any tips on improving stability? Can the base be braced in any way? Any help would be greatly appreciated.

[MitchellMc]

Hi @hambly,

You are correct in your concerns about not wanting to disturb the fencing, and here is some information to read through.

Ground screws are great for four posted builds, like a pergola. When the four posts are connected together, the whole structure gains significant rigidity. This same principle can't be applied on the fence, and it will always be susceptible to wind shear load. The Otter 690 x 90mm Ground Screw Stirrups could be an option, but as you've observed, depending on the soil type in your area, they likely wouldn't have the same holding power as traditional concrete footers. You'll need to speak with the manufacturer of your chosen composite panel fence to determine the required footers. If this were one of our products and you have details, I'd be more than happy to track the specifications down for you.

Provided the ground screws are set out away from the fence at least 50mm, you'll have an arc of 180 degrees at the front to place a bar and twist them into the ground.

Your health and the health of those around you is the number one priority. The most concerning part of the project is likely digging holes near the existing fence and working near it. Perhaps you might like to outsource that part to a professional and have them dig the holes and concrete in posts. You could then fix the panels in place. Regardless of your choice, I urge you to wear appropriate PPE suitable for exposure to asbestos, including a respirator and disposable overalls. 

Please let me know if you have any questions.

Mitchell

[hambly]

Cheers @MitchellMc 

This is one of the products I was looking at https://www.bunnings.com.au/ekodeck-67-x-15mm-2-7m-leatherwood-designer-series-screening-composite_p...

Would be looking to install standard 100x100mm timber posts and then fixing this in a similar style to the features pictures, so stacked 3 panels high horizontally. 

Would ekodeck have suggested footings for this? Given its a multiuse product?

Thanks,

Harry

[MitchellMc]

Hi @hambly,

Thanks for clarifying, as there are composite fence panels out there. Just to clarify, the product you linked to is a single piece of 65 x 17mm composite screening at 2.7m long. So, there are no panels as such. In the images, 21 lengths are fixed to the posts to achieve that look and height.

You have the Ekodeck screening installation video. They've used timber posts concreted into the ground at 900mm spacings. The footers for these posts are 600mm deep and 300mm wide. Given the substantial nature of the footers in their guide, I recommend you consider going with a concrete footer instead of the screw-in.

Mitchell