How to close gap under fence?

[Basher123]

Hello,
I have roughly a 500 mm gap between the concrete slab and the back fence, and I’m unsure how best to make this area neat and functional.
We recently concreted around the house as we are on H2 soil, and we’ve noticed water buildup under the soil after every rainfall. The concrete is graded toward the fence, so I’m considering digging a shallow swale drain, lining it with builder’s plastic, and directing the water into a shallow pit.
I already have pebbles that I plan to place over the plastic.
The property behind us sits about 500 mm higher than ours, and some landscaping material is coming onto our side. What would be the cheapest and most efficient way to close off this gap? I mainly want to tidy the area without having to pay for material removal.

 

 

 

[JacobZ]

Hi @Basher123,

Thank you for your question about how to address some soil subsidence under your fence.

The simplest solution would be to install a basic retaining wall against the line of the fence. This will help to hold back the soil from the other side of the fence. Check out How To Build A Timber Retaining Wall for some guidance on this process.

You could then install a swale, or a french drain, along your side of the fence. A swale would look nice, but it would drastically limit your ability to have anything on top. If you instead used a french drain, like the one shown in How to install garden drainage, you could then build up the soil above it and put some plants or planter boxes on top.

Allow me to tag our helpful members @AlanM52, @Noyade and @JDE to see if they have any thoughts about the best approach.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob

[AlanM52]

Hi @Basher123,

With regard to the landscaping material have you checked the situation over the other side of the fence and if not I suggest you do that.

Doing so will establish a baseline reference (add diary entry) to what might pop-up down the track.

I am leaning heavily towards a 'open' french drain because you end up a with a 'instant' garden bed (with the right plants).

I only know that because our younger daughter is a qualified horticulturist and I have randomly picked up info like the tips & tricks thing.

I mentioned about checking over the fence because IMO there is a obligation that everyone ensures their fence plinth boards are clear of everything.

I suggest installing something like 200 x 50mm (2.4M) treated pine sleepers along the plinth boards.

That's about it...

Cheers

[Basher123]

On the other side there is retaining wall, and between the retaining wall and fence the have filled up with soil and sand and rocks..

I think installing a 200 x 50 treated pine sleeper should work. 

Not planning to plant anything in the area.

I don't want to install a french drain as it seems more practical to deal with surface water on the surface.

Thank you.