Screamo":in7vmt9s said:
I'll keep it short for yours and my sake. I plan on building a 10' planting trough. The issue I'm having is knowing the measurements I need. I already know I want it to be 10' in length, 2' in width and 2' in height. The issue I have is working out the thickness and height of the plank that I want. Because it's a custom build I can't compare it with something else. I have a visual image of what I want, I just don't know how to go about knowing the measurements of the wood that I've just mentioned. How do people work out what measurements of the wood they need if they are building something from visualisation? I'm not sure if what I have written makes sense, it makes sense in my head though I don't know if it will to you. I would really like some lessons from you guys and get an understanding and I do truly appreciate it, I posted a topic months ago and I still remember plenty that I was taught back then. It really does help. Thank you.
This is actually fairly easy. Timber is only supplied in a very few thicknesses, and you have to pick the nearest one. For a clue, a scaffold board is about 38mm (1-1/2") thick. Picture it mentally made of scaffold boards, and ask yourself if you saw it thicker or thinner than that, or is that about right. My experience is that this is a massive planter, and that you'll never shift it, so you'll have to build it in situ. (Why so deep, BTW? Most plants don't need anything like that depth of soil). If you were to make it out of 25mm timber (lots of people use decking, for instance) you would need intermediate cross members to prevent the weight of the soil (and water) bowing the sides out. However, when you design this, remember that most fixings are going to fail in the end, so a cross member screwed into end grain decking is going to be failing in a very short period.
The other approach to something like this is to build a strong frame, and then use less chunky timber to infill between the frame members. Given how imposing a 10' x 2' flat planter wall might look, this would be something worth considering.
There's a thread here somewhere of some planters I made 8 or 10 years ago of scaffold boards. I can't find it now, but if anyone can, these are probably only about 6 feet long (it's raining.......I'm not going out to measure them!). Imagine something nearly twice as long and 50% deeper and wider.