Wanted a second opinion other than my own incompetent one!
I've a retaining wall that'll be 900mm above ground level, 10M wide, about 3M at the sides. Digging down with the JCB, which I'd not used before, I created a trench somewhere between 300 - 450mm wide. It's widest at the mid-point (5M) which I assume is good fortune. I was surprised how deep I had to go, I was at about 800mm in parts and still not really hitting what I'd consider hard ground, but I was also thinking about the level of work regarding the filling so didn't go much deeper. Also having no experience the depth became somewhat variable.
The foundation thus is 300-450mm wide and varies in depth between 150mm and 450mm deep (it took two long hard days of cement mixing to get it filled). There's about 300mm to get to ground level.
Being 900mm above ground level I read that I'd be stupid going for a 100mm thickness wall so am planning to go with 220mm blocks. The question is whether being the foundation is only 300mm in places and the height is only 900mm I'd be better going for the medium density 14kg (still 7n) blocks to give the foundation an easier life, but in-hope that the weight is still enough to hold back 90cm of soil. Dense blocks are 20kg.
Your expert advice is much appreciated.
I've a retaining wall that'll be 900mm above ground level, 10M wide, about 3M at the sides. Digging down with the JCB, which I'd not used before, I created a trench somewhere between 300 - 450mm wide. It's widest at the mid-point (5M) which I assume is good fortune. I was surprised how deep I had to go, I was at about 800mm in parts and still not really hitting what I'd consider hard ground, but I was also thinking about the level of work regarding the filling so didn't go much deeper. Also having no experience the depth became somewhat variable.
The foundation thus is 300-450mm wide and varies in depth between 150mm and 450mm deep (it took two long hard days of cement mixing to get it filled). There's about 300mm to get to ground level.
Being 900mm above ground level I read that I'd be stupid going for a 100mm thickness wall so am planning to go with 220mm blocks. The question is whether being the foundation is only 300mm in places and the height is only 900mm I'd be better going for the medium density 14kg (still 7n) blocks to give the foundation an easier life, but in-hope that the weight is still enough to hold back 90cm of soil. Dense blocks are 20kg.
Your expert advice is much appreciated.
