Terrace Project : The Bamboo Containers Strike Back

Since my lovely neighbor decided to cut down all the trees that made my place a small green haven, ("because it looks cleaner this way!... Don't get me started 'bout it), I've had to build another pair of bamboo containers, to add another hedge to my terrace an regain some much needed privacy (not that I don't like my building-across-the-street-neighbors, but you know).

As the containers I built back in 2009 aged pretty well, I'll use basically the same plan.
Sorry, you'll get less pictures this time, the build method is the same ; and the picture quality is average, I only had my dying smartphone at hand,

I begin with a good Sketchup session to get the dimensions right, and find out precisely the materials I need to buy... You can download the sketchup file here if need be. Looking back, I was only half convinced by my choice of using OSB as a bottom board when I built my first set of containers (even though it's still holding 8 years later). Instead, I'll use this time a 20mm thick solid pine wood board, that look much tougher to me. And affordable, at 12.20€ the 200x60cm board ; I cut them down to the final 138x51cm by clamping the 2 boards together and cut both at the same time with a circular saw. Just like the first time, I use 20mm thick weathering boards on the sides. Everything's glued together with PU glue, then screw with stainless, deck screws.
Actually, I changed my mind at the last minute and decided to make the containers 5 boards high instead of 4... So I went back to get some more, but unfortunately they didn't have the same model available, only another slightly wider one... So I had to adapt a bit for my second container, meaning the two of them aren't exctly identical. My OCD self will have to live with that! Four layers of mahogany tainted wood surface coating (inside and outside), to protect and finish it ; I used a product from the "Syntilor" brand, it's advertised as holding 10 years, we'll see about that. I perfect the water tightness with some silicon caulk, to prevent the wood rotting from water infiltrations on the long term. I won't use a tarpaulin inside this time, contrary to what I did on the first containers I built. I'm not convinced about how it handled humidity and roots ; Instead, I brushed two thick layers of tar (from tarp to tar... basically got rid of 1 letter). I stop a few inches below the top of the container for aesthetics reasons...
The product smells really bad, make sure you use a prooer filtering face mask, as well as gloves, security glasses and long sleeves...
Once dry (well, it actually never completely dries), it becomes inert and doesn't smell at all, and provides a watertight layer between the soil and the wood.

The bottom water outlets are, just like last time, plastic air venting grills, caulked to the bottom. Well, bad idea, should have done that before the tar, the silicon reacts badly to the tar, turns yellowish and cracks... Well, it wasn't critical, it'll do.

To enhance visual privacy (especially while the bamboos are growing), I install a reed screen above the containers :

• on the right hand side, a metal post is screwed to the container, with an additional diagonal support to help handle the cables tension.
• on the left hand side, I directly drive 3 stainless, heavy-duty screw-eyes in the last post of my wooden fence.

Finally, I put 3 steel cables in between them posts, and I attach the reed screen on them. Ok, now comes the time to fill'em up!

I first put a terracotta tile above each grill to protect them from the weight of the soil above.
Then, I add a 6-7cm layer of small stones, to keep a draining layer, which I perfect with a bag of gardening pozzolan I had laying around.
Then I put a double layer of geotextile over the whole thing, to prevent soil and roots from clogging the drain too quickly. I finally add some soil (a bit over 5 bags of 60L in each container), plant 6 bamboos, taaa-daaaa!

I install four 12V LED waterproof spot lamps, to blend in with the other 2 containers... And I'm done, just have to wait for the bamboos to grow a bit, and I'm done with the bloody neighbors-across-the-street hassle!