How to repair path and lay decomposed granite?

[TimD]

Hi,

   Having installed Ag pipe down the side of my house, it is time to repair the path I dug up which is now quite uneven. It was covered with this decomposed granite by the previous owners so I want to use the same and top up existing undamaged path. The path has a small slope and I read I should use 4% off white cement to stabilise the granite  (I guess I just mix it in).

My question is how best to level out the path I've dug up? Please see pic. I was simply going to scrape up high points of the soil with a spade, spread some left over soil I dug up and level with a rake and tamper it down with a tamper. Then lay down about 5mm of the decomposed granite -  however I feel this is too simplistic and may end up creating more work for myself trying to get it level.

When I see other posts they use road base and paving sand etc, however they seem to be laying paths from scratch - but I just want to "repair" an existing path.

I estimate I have 35 square meters of path to repair and top up.

• What is the process to do this? 
• Should I be using some sort of sand or something else to get it level or can I just flatten it as best I can with left over soil and then top with the granite? 
  • If so, what should I use and how much?
• How much decomposed granite should I use assuming 5mm and is that deep enough?
• Do I just mix in the off-white cement with the granite? ie need for water?

Many Thanks

Tim

[JacobZ]

Hi @TimD,

You’re definitely on the right track, but a little extra preparation will help your decomposed granite path last much longer. 

Instead of levelling with leftover soil, it’s best to use a more stable material such as road base. Spread a layer of around 30–50mm where needed to bring the path back to level, then compact it firmly with a tamper or plate compactor. Soil tends to settle and wash away, which would leave the granite uneven again fairly quickly.

When it comes to resurfacing, 5mm of decomposed granite will be too thin to provide a durable surface. Aim for at least 20–30mm of depth across the whole area. Spread it evenly, rake it smooth, and then compact it down well. For your 35m² path, this means you’ll need roughly 0.7m³ for a 20mm layer or around 1.0m³ for a 30mm layer.

To strengthen the surface, mixing in about 4–5% cement with the decomposed granite before laying will make a big difference. Dry-mix the cement and granite thoroughly, spread it over the base, compact it, and then lightly mist with water to activate the cement. Avoid overwatering — you only need enough to bind the particles together. This process will help stabilise the path and prevent erosion.

By creating a solid base, applying enough granite, and stabilising it with cement, you’ll end up with a more durable, even path that should last for years with minimal maintenance.

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

Jacob

[TimD]

Thanks Jacob, 

   Yes I thought I was taking too many short cuts. Can I use this 20mm concrete aggregate as the base? I have quite a bit left over from the Ag pipe project or is 20mm too coarse?

Thanks

Tim

[JacobZ]

Hi @TimD,

20mm aggregate would be fine, just make sure to tamp it down so it is nice and solid.

Let me know if you have any further questions.

Jacob