Kenthurst site cut and two-tier sandstone retaining wall

Kenthurst is big-block country. Sheds, horses, long gravel driveways and clay sitting over sandstone. The owner of this property came to us with a clear brief: a car park around the shed that a truck could actually turn in, and the bank between the shed and the house held back properly, with a wall that looked like it belonged on the block.

We priced the whole job, site cut to turf, and booked it in as a three-week build.

Week one: the site cut

You can't build anything until the levels are right. The ground around the shed fell away in two directions, so the first week was a full site cut and prep. The 5-tonne Takeuchi did the bulk cut, the Bobcat trimmed and shaped, and the truck and dog ran spoil out and roadbase in. Every level was set off a laser so the finished car park drains away from the shed slab, not into it.

This car park is sized for a truck, not a hatchback. That means a wide apron right around the shed, a turning circle you can use with a trailer on, and a compacted base that carries a loaded truck and dog without rutting.

Week two: the wall

The wall is two tiers of 2-metre A-grade sandstone blocks. Each block is roughly 2 m long, 400 mm high and 400 mm deep and weighs around 1.4 tonnes, so every one goes in on the block grab. The rock saw on the excavator cuts the blocks on site for the curve, the corners and the steps, which is how you get tight joints and clean ends instead of chipped ones.

The footing is compacted roadbase, laser-levelled. Every course is string-lined. The wall follows the curve of the car park and steps up to the lawn, with a set of sandstone stairs built into it where the owner walks between the house and the shed.

Week three: drainage, gravel, turf and gardens

A wall only lasts if the water behind it has somewhere to go. Behind both tiers there is geofabric, aggregate backfill and a socked ag line run away to stormwater, so the clay never builds up pressure against the blocks. That is the difference between a wall that is still plumb in twenty years and one that is leaning in five.

With the wall in, we finished the car park and driveway in gravel, graded to the laser and rolled so it sits level to the millimetre. Then the terrace above the wall was turfed, the garden beds along the top course were built up and planted out, and the stone got a pressure wash. All rubbish left the site with us.

The kit on this job

• 5 t Takeuchi excavator with block grab and rock saw
• Bobcat for trimming, spreading and finishing
• Truck and dog for spoil out, roadbase and gravel in
• Laser level for the site cut, the wall footing and the gravel finish

If you're in Kenthurst

Most of Kenthurst sits on the same clay-over-sandstone as the rest of the Hills and the Hawkesbury. Walls fail here for two reasons: no drainage and no footing. This one has both done properly, and sandstone only gets better looking as it weathers in.

If you have a shed, a bank or a driveway in Kenthurst that needs the same treatment, Jesse will come out, measure it and put a fixed price in writing.