Posted: 03/05/2014 at 13:32
Hi Everyone, However, the builders dumped a load of soil and rubble on it from making a new patio and in my madness I decided to try and turn it into a sort of raised bed. I laid more soil - 4 tons of it in fact - on top of the builders mess and then shaped it so that there was a bank of earth in the middle and a flatish bit around the outside. I had planned to put in wooden borders where it sloped away ( to stop the gravel slipping down ) and then after planting up with wildlife friendly plants I was going to cover it all with gravel and rocks and driftwood, etc. Its difficult to describe it all, pictures would be far better, but I don't know how to add them here.
Well, it sounds like a s***-heap ... but the pictures don't look so bad. I thought you had a big round heap in the middle of a square lawn.
There's a steep earth bank by the canal near here that's been slowly creeping downhill for years. The towpath's getting slightly narrower every year, but it's a very slow process. You should be alright with ground cover stabilising it, but if it flows down against that wall on the right side you'll get damp issues there. You could just shovel it all back to the top in five years' time, I suppose.
Looking at the nice view, I can believe you when you say digging beyond a certain depth is hard. I've tried digging in the Dales and been tampted to put the spade away and make some dynamite. If you don't want to go to the trouble (and rubble) of making holes in bedrock, there is still a way to concrete in a post. You need to build forms for the concrete first, out of cheap MDF board and 2"x2" pine. Put all the pine and screws on the outside so the inside's nice and smooth, sit the thing on bare bedrock, shave bits off the underside until it sits level, stand the post in the middle of it, pour in the wet concrete mix, make sure the post's upright and leave it to set. Once it's done you can dismantle the form and use it for the next one or you can do them all at once, toss the MDF in the bin and use the pine for kindling.
A fence built this way won't have the stability to stop horses or stay upright in a wind with those lap panels on it (I swear they're modelled on windmill sails) but if you're only putting in 2' posts and the bottom 9" of each are in the concrete you'll have some pretty stable things.
Then you put rails across the posts on the uphill side so the weight of the soil is pushing wood against wood, not pulling all your nails out. Then you can put your chemical-soaked rot-resistant retaining wall on the uphill side of the rails. Make sure there's soil (or the builders' waste material from under your mound) packed in downhill of the fence bases to stop them sledging away.
The fence will slowly get toppled by slumping soil, but it'll be something your grandchildren have to fix one day.
Just kidding about the dynamite. Too risky. I'd use TNT.