I've been reading many "how to" articles online about dry stone wall construction and I'd like to give it a go! I'm constructing a new raised bed about 6' x 6' and have a considerably large pile of what I believe is blue slate near by. Any tips on using this type of stone or tips on dry stone construction in general would be greatly appreciated.
Slate's pretty brittle and unless you've got perfectly level slabs of it (which you most likely do not) it can also tip over or outwards under the pressure of the soils in the bed if you go with a strictly mortar-free construction. Personally, I'd use just the teensiest bit of mortar with it; if you place this carefully towards the back of your slabs (ie the inside of the bed), you can get the appearance of drystone but have the added stability that mortar gives you.
My father did a lot of dry stone walls for terraced gardens. From memory he always had the largest rocks at the bottom on a very level solid foundaton. By this I mean down to the base soil not the soft dug stuff. He also had the wall leaning slightly inwards to wards the backfill soil. As he worked the wall up he would fill it behind as he went. The walls would be about a foot wide at least and it was a real jigsaw of fitting rocks together sometimes using the hammer to shape a piece. He used mainly rock to do his work but I would suspect the solid base and tilt would also work for this slate if it is reasonably thick. Just read in an article below that they use cross tie stones to help with stability Canadian link http://www.jboyweb.com/drystonewall/ British http://handbooks.btcv.org.uk/handbooks/index/book/61 Australian garden drystone http://www.burkesbackyard.com.au/19...styles_and_features/building_a_dry_stone_wall Liz
Just wanted to throw in my vote for the bctv.org website in the post above. We bought a new home and ended up with lots of rocks from putting in an irrigation system; I now have a drystone wall about 60 feet long, ranging from 10" to 3' tall. It is mostly round fieldstone - what they tell you NOT to build with if at all possible. That website was THE website to read and learn from. I have NO experience with masonry, but that taught me all I needed to know for what I was doing. My hard-learned tip for you: Start with one section 2-4 metres long, and count on re-building it 2 or 3 times. You'll wake up in the morning and thing "what the #*% was I thinking?". But once you have the trick, it comes much easier. Read the instructions on rock placement well - 'breaking the joint' is harder than it sounds. At least with round fieldstone! Sounds like you have some good flat stuff- you'll be just fine. Good luck! P
