Retaining wallCategories Uncategorized
The day the water tank was installed I had also planned to dig the post holes for the retaining wall on the north side of the shed. This is a vehicle surcharge wall (fancy name for “I’m going to drive on the uphill side of it, so it needs to handle the weight of vehicles”) so there’s shorter panels and therefore more posts. In all I needed 22 post holes, 450mm wide and up to 1.2m deep.
Hired a 1.8t excavator, post holer attachment and a biiiig auger. Unfortunately all that gear ended up being almost entirely wasted due to multiple equipment failures. But I did get 3 holes dug, which was enough to prove a couple of things:
- There’s a lot of granite ~1m down, and
- The holes are so big, and close together, that the wall between them keeps collapsing.
So I went back to my engineer and asked if I could make footing one (hopefully shallower and narrower) long trench, position all the posts in it and fill the whole thing with concrete. Engineer came back and said yes, so I hired my favourite excavator (which is my favourite both because it works, and because it’s cheap 😉 ) and set to work digging the trench.
Still had the machine for a few more hours, so I got started scraping off the topsoil for the shed site. The only hard part of this was trying to do some sort of dust suppression without an extra set of hands to wield a hose – despite last night’s rain the ground here is absolutely bone dry, and the soil is a mixture of sand and desiccated clay which turns to dust as soon as you disturb it.
I’d tried to do a bit of this work when I had a bobcat on site, but the machine was too small to get through the hard soil. I’ve been using the exxy enough recently that my bucket control has progressed to the point where I can use it to scrap soil, rather than just making random holes. 🙂