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Hi all,
I am putting stairs in instead of the stepping stones for our front yard and hoping to extend it to the door which means to change the current tiles to the same Travertine.
Would someone be able to assist in guiding me on the base work prior to and if it's best to lay timber sleepers as a base instead of concrete?
This is the inspiration
Hi All,
I have done a fair bit of excavation and with the recent heavy rainfall, it has created a saturated clay soil (very gooey like). This is 150mm below ground level.
Does this mean I need to dig deeper and reach a more solid base? Or can I just add 10mm bluemetal or natural roadbase and keep compacting it?
Hello @toffeeapple
Since you plan to use retaining wall blocks instead of a heavy concrete base over the saturated clay, the preparation remains crucial to ensure stability and prevent shifting or settling over time. The saturated clay can cause issues if not properly prepared, as it doesn’t compact well when wet.
To start, consider digging deeper if possible, to reach firmer ground. If that's not practical, focus on drainage and compaction. Begin by adding a thick layer of road base (100mm to 150mm), as it provides better stability than a thinner layer of blue metal. Compact this layer thoroughly with a plate compactor to create a solid foundation. If you’re concerned about moisture, incorporate a layer of coarse aggregate or gravel before the road base to aid in drainage and help prevent moisture buildup.
You may also want to lay a geotextile fabric between the clay and the base material to keep the road base from mixing with the clay and to ensure long-term stability. This fabric helps maintain drainage and prevents the foundation from shifting.
Once the base is prepared, you can start laying the retaining wall blocks. These blocks are designed to provide structural support but ensuring that the base is well-compacted and stable will help prevent any future movement. If drainage issues persist, installing a French drain or sub-surface drainage around the perimeter of the wall can direct water away and keep the base dry.
By properly preparing the foundation, you’ll ensure the retaining wall blocks remain stable and prevent settling or shifting as the weight of the wall and surrounding materials settles over time.
If you need further assistance, please let us know.
Eric
Thanks Eric.
I have excavated a bit more so it is now 200-250mm below ground level.
The ground is firm but can still be dug into (not easily).
I have placed a thin layer of blue metal 10mm and will be compacting it with a hand tamper.
Then I will put a non woven geotextile fabric on top and fill it with 100mm of roadbase and then 50mm depth of blue metal again as my bedding for the retaining wall block steps.
Question is, do I need drainage pipes? The land slopes away from the house but I don't want the water to pool on the first step.
I know I need to make a slight 1/8 inch on the steps to allow water to drain away but do I need a pipe below as well?
Hi @toffeeapple,
It sounds like you’ve got a solid base preparation plan in place. Given that the land slopes away from the house, drainage might not be strictly necessary, but no one ever finishes a project and regrets adding drainage. Installing a pipe now is a great preventative measure, ensuring water doesn’t pool on the first step or cause issues over time. If you do decide to include one, a perforated ag pipe wrapped in geotextile fabric and set in gravel would help direct any excess water away efficiently. It’s always better to overprepare than to deal with drainage problems later.
Mitchell
Hi Mitchell,
I just don't know where to attach the pipe as I cannot locate the storm water drain
Hi @toffeeapple,
Council keeps property plans which you can access. They'll likely show drainage lines through the property. Alternatively, you could try a service such as Before You Dig.
Mitchell
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