How do I determine if I need a retaining wall or not?

Question

Hi all,

I’m preparing my front yard for turf and I’m a bit unsure about how to deal with the boundary fence side because my block sits higher than the neighbour’s side.

The existing timber fence runs fairly level, but my yard naturally grades up toward the house and driveway. In some sections the existing soil is already close to the lower part of the fence, and I’m concerned that once the yard is properly graded and I add lawn underlay + turf, the finished lawn level may end up higher than the lower fence/plinth area (this lower section can be covered correct?)

I’ve attached photos showing the current soil levels, driveway, fence and overall slope.

I’m mainly after advice on what the best solution would be here:

* Does it look like the yard can simply be graded/sloped down toward the fence and still end up with a sensible lawn surface?
* Or does it look like some form of retaining edge/wall is needed along the fence?
* If retaining is needed, what would you recommend using for a relatively small height difference that won’t look odd in a front yard?
* Would you remove some of the existing soil first, or retain the current higher level and build the lawn from there?
* Is there anything I should be careful of with the existing fence when setting the finished lawn height?
* Any other advice is appreciated as well!

I’m hoping to get the front yard rough-graded and ready for turf soon, so I’d really appreciate any suggestions on the simplest and most practical way to approach it while not upsetting my neighbours!

Thank you in advance,

Brad - new home owner

Dave-1 · Answer

Good Evening @bradh

I dont think you need a retaining wall (and I love retaining walls) Removing the stones and potentially some of the clay/rough soil to give some space to some decent soil and new grass will bring the lawns edge up to the base of that timber for the fence and not cover it. I dont have a high opinion of what is left on the ground after new installs, It generally seems to be the heavier side of soil/clay and builders refuse that is easier to be left behind.

Have a think about an automated sprinkler/drip feed before you lay down any soil as it would be far tidier to do before the grass is laid.

Congratulations on becoming a home owner :)

Dave

Nailbag · Answer

Hi @bradh

Because the fences plynth boards aren’t intended to retain virtually anything and to extend life, I would run a retaining wall directly in front and to a height slightly above your intended finish level of the front lawn.

Personally, I would then run 100mm x 5mm steel edging inline with the inside edge of the column on the far right window to boarder a fence line garden bed. Good landscaping supplies sell them in 6m lengths for around $100each and will last for decades.

You can easily curve and fix the edging into place with 300mm timber stakes and be cut to length with an angle grinder. You just use hex headed self-drilling 25mm screws to fix the edging to the stakes. Or drill pilot holes through the edging and use wood screws.

Nailbag

EricL · Answer

Hello @bradh

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your lawn and retaining wall.

Your garden is currently in its rawest form as the soil itself is not yet levelled and is still full of debris. The typical thickness of a roll of turf is around 40mm+. Therefore, if you were to install rolled turf you would need to take the thickness of the roll into account. Not only do you need to grade the surface, but you'll also need to take into account the addition of garden soil to prepare the surface for the turf.

Looking at the photos you've shared with the community, it appears that it has a lot of stones in it. But the soil itself looks to be in good condition. I would therefore suggest removing as much of the stones as possible so that you'll be left with good plain soil. This will save you from having to add a large amount of garden soil and you can get away by topping it up from 30 to 50mm.

Using your cement walkway as a reference at the front of your house, you would need to have a dug-out space of 90mm+ conservatively and base the slope on that going down to the cement public walkway. You should end up with a nice soft slope that is in theory in line with the bottom of your existing fence. It's important to take into account the materials you'll be adding to your garden so that it does not go higher than the bottom of the fence line or at least be in line with it.

If you were to grade the surface and provide a provision for the soil and turf, there would be no need for a retaining wall. The things to watch out for are your plumbing fittings a that may be running across your garden, so be careful where you start digging. My best advice is to plan it out carefully before you make any purchases. I've placed a sample image below using AI to give you an example of what it could look like.

Let me call on our experienced members @Dave-1, @Nailbag, @mich1972 and @ziyadali for their recommendations.

If you need further assistance, please let us know.

Eric