Hi people who know what they are talking about.I've been renovating my whole garden, and had an idea about building some concrete block planters to create something a bit like the image below.What i'm trying to doSo I've dug down, compacted some sub-base, laid a foundation (Hopefully deep/wide/strong enough) and have basically completed all my block-work to a sufficiently amateur standard. I've left the middle of the planters free of concrete so the water has somewhere to hopefully soak away rather than giving me a pond and knocking the wall down.I intend to render the boxes. And this is basically where i'm now stuck.Where i'm at nowBefore rendering do I need to waterproof the blocks so no water can seep in and potentially freeze/blow off the render? Would it be something that is painted on? Will render stick to whatever is painted on? Will I need to use a waterproof membrane?)Will I also need to add beading to render up to? Is there special render that is stronger or flexible to prevent cracking or would a general exterior render be ok?When it comes to actually filling up the planters for planting, would i use larger rocks initially, followed by smaller and finally a top soil/compost? Are there any plants to avoid that have large roots that also might blow open my hard work? I currently have no drain holes in the side as I guessed (hoped) that the void in the middle of the planters would be sufficient for drainage, I can obviously still add these at this stage if recommended.I'm in the UK by the way if that helps the answer, so there will be minus degrees C on the way. Any help at all would be appreciated. via /r/DIY http://ift.tt/2vTJmXM
