Making a dry rubble wall
I’ve recently turned most of the rubble in my garden in to a dry rubble wall seat, complete with wildlife hotels. Making a wall without knowing whether you’ll have enough of the right materials is pretty hairy but having sorted most of the rubble through two or three times I was pretty clued up about what I could use and whether there would be enough of it. Here’s the steps I went through to make my wall.
Step One – I sorted the rubble into three piles according to material – concrete block type rubble, brick type rubble and slate type rubble. Then I ordered the separate piles according to size – big, smaller and even smaller. This took up a lot of time initially but speeded up the wall building process and made it easy to grab the piece of material I wanted when I wanted it.
Step Two – I then prepared the soil around the area I wanted to wall. I cut away the bank behind the wall to a vertical plane, allowing enough space between it and the front of the wall for the stone plus a bit extra to back fill with soil. I did this because I want to plant up the area behind the wall and also put fence posts in to the soil. I then made a flat level base where the wall was to stand using a spirit level, a spade and a big pair of feet, or girt dabs as my granddad used to call them. I still don’t know what a girt is!
Step Three – Dry stone walling is a gravity based system so always use your large stones at the bottom and at the corners to provide stability. Your wall will have two parts – a very tidy front wall and a secondary messy supporting wall. This messy behind will be made up of all the rough bits of rubble and stone that didn’t make the grade for the front wall. In a way my rubble was quite convenient in that I had some old concrete block for the bottom layer.
Step Four –
As you place each layer of stones on your front wall make sure they are balanced in favour of gravity by placing the stone so it runs from front to back with some of the stone hanging over the back. These overhangs can then be supported with the ugly stones in your behind the scenes wall. This allows for the weight of the wall to be spread along many points and for the whole thing to feel very stable and unlikely to shift, even if the area behind the wall gets flooded out. Plenty of rubble also helps drainage. I used a variety of pieces of concrete block and good slate for the higher levels and I placed them carefully so neither material dominated the skyline, as it were. Some of the concrete block I had to adjust with a sledge hammer, knocking angular bits of to make a flat worthwhile stone. The odd pieces I knocked off were then used at the back of the wall. Nothing has been wasted.
Step Five – Remove any wobbles at the front of the wall with smaller pieces of slate or stone. This is a bit fiddly because no one piece of slate is the same as another and you have to hunt around for exactly the right thin piece to make for a snug fit. Its also quite rewarding because as you progress your skill improves and you find yourself working more successfully with the materials. Once you are happy you’re stones are strong and wobble free back fill the area behind the wall with soil and stamp on it with your feet till the soil feels solid under foot. I put all my rubbley soil in here so the other areas contain the best soil for growing veg. This area behind the wall will be planted up with plants that don’t mind poorer soil. Actually I dug most of the rubble out of this part of the garden and there were nice low lying plants growing on top of them.
Step Six – Proceed on to the next level making sure the stones you use are not bigger than the ones beneath. Try and overlap stones to make a rough – but not exact as this is impossible – brick formation. And remember to keep on removing the wobbles. After completing another layer back fill the area behind the wall with more soil and stamp down until firm.
Step Eight – Carry on building, repeating the process of wobble removal as you go along until you’re ready to put your large flat bottom friendly stones on the top. Finally back fill the remaining area behind the wall with more soil.
Step Nine – The holes in the bottom of the wall can be used to make little hotels for insects. They love having hiding places to hang out in. Tubular materials like bamboo are good so if you’ve got any canes looking a bit worse for ware cut them to the right length and lay them in the hole. I also used bits of old crock and small pieces of slate, as well as other random bits of junk.
Step Ten – Sit down and enjoy the view. Making a wall seat is much better fun than just making a wall because as you slave away in the soil you’ve got something to look forward to. Another word of advice – don’t try this on a really cold day. Although some parts – like the digging – warm you up there’s a lot of careful and slow stone selection and placement. In my frosty old garden I could feel my frosty old bones aching by the end of the day.
Dry Stone Walling by Brooks, Adcock and Agate. Published by BTCV. Available at http://handbooks.btcv.org.uk/handbooks/index/book/61