Some time ago I made this bed for, and with my kids. The idea was to bring some nature into the Kid's room and for them to have a bunkbed that inspired them to climb on and in it. I also wanted them to experience that wood isn't a material that is made, but one that grows, that has a life in it, and so the idea came up to collect wood that had been cut to clear the forest. Even in a small forest in the middle of Berlin it took us only about five minutes to find a large amount of usable wood. Since it was such a fun project for the kids, because they simply love their beds, and because this is a cheap and very green way of making a bunkbed, here is an instructable of how to make one....
Ok, so the first thing you need to do is to find a place in your room for the bed and find out what size mattress. if you know the size of the mattress or two or three, start by making a simple support structure for the mattress (slatted frame). You can normally find loads of those in the streets.
Step 1: Finding and Cutting the Wood
To make the bed you need the wood. Find a forest and have a look around. Depending on where you are you might be lucky and a lot of wood that has been cut but is to small to be claimed by anybody is still lying around. If you find large bunks consider how long it has been laying there, because there might be animals living inside. If that is not the case go ahead. For a tough structure, depending on the wood of course, branches that have a diameter of about 5-10 cm are good. Make sure to take at least two straight pieces per bed in the length of the bed. Take enough wood to choose from later and look for interesting branches, V-shaped is very handy...
Collect smaller sized branches for the rails of the bed. Let the kids try and find the right wood, they will have a lot of fun doing this and will recognize "their" branches in the finished bed, which is a really nice thing.
Depending on the age and skill of the kids, let them do some of the sawing. I strongly recommend a Japanese saw for this. It is sharp and easy to handle even for the kids (because it cuts on the pull-stroke which is easy for them to do). Make sure to observe the kids while they cut and cut the bigger branches yourself! If the bark is loose take it off before taking it home. If not leave this for later, when you know which of pieces you actually use.
Step 2: Removing the Bark From the Wood
Removing the bark from the wood can be a most tedious job and it is a good idea to only do it with those pieces you actually use. So don't do this to all the wood, but do it every time you have chosen a piece for the bed.
I tried a couple of tools and can't really recommend any of them! A disc grinder is probably the nicest but makes a lot of dust. Scratching the bark of with hand tools takes longer but you can do it inside...
Step 3: Finding the Right Screws...
For the bed to look nice, you need nice screws. I took torx screws, because you can reuse them many times (we have moved with the bed actually, taking everything apart and putting it back together in the new flat). I also liked the look of stainless steel screws. Try to get screws in a variety of lengths, because it is hard to tell what you will need. If possible find screws with a neck. In some cases it was a good idea to shape the branches a bit so that they would better fit together but in most cases all I did was pre-drill a hole for the screw with a drill that has half or two-thirds of the diameter of the screw.
Step 4: Ataching Branches to the Mattress Support As a Frame
You obviously want your beds to be level, but the branches that will hold the frame are not completely straight. So what you will need to do is to first attach the branches that hold the mattress-support to it. Here you are looking for straight pieces of wood.
Once you have the mattress frame with strong branches attached, you have to find the right spot for the joist hangers on the wall. The cheapest option is to use these metal brackets/joist hangers. You could also build such support of wood.
Step 5: Ataching the Bed to the Wall
once you have the mattress support and sides ready it is time to attach it to the wall. You need another person to help or a lot of clamps and temporary support. Start with attaching one wall support to the wall. Then let the other person hold the mattress support so that it is level and mark the spots for the other wall supports on the wall. attach the other wall support and you have at least two, maybe three of the corners supported. Check if everything is level, you can still correct any errors by cutting a bit of the wood that is placed in the wall support. When it is ready attach two or one temporary support legs for the bed. Set up all the beds you are making.
Step 6: Making the Bed Strong
It is now time to give the bed the structural support it needs. The simplest solution is to put legs on the bed horizontally. To me this isn't a very elegant solution but depending on the room it can be the best option. What I did was to give support for each of the unsupported corners by diagonal branches fixed to the wall/floor. This made it possible to lay a large futon mattress on the floor under the beds for the kids to land on when climbing and jumping on the beds. It is also the place where we sit and read to the kids before sleeping. And it makes for a great hut under the beds covered with blankets!
After attaching the support, take off the temporary support and see if it can hold you! (it should hold a grown up person in my opinion, our bed can take it when an adult sits there with the kids). If you feel that the bed is not strong enough yet, add more support. A good way to increase the stability is by using V-shaped branches.
By the way, wood is strongest in its natural shape, so a 10cm diameter naturally grown is much much stronger than a 10cm diameter cut out of a larger log.
Step 7: Adding the Railing
A bunkbed needs a railing. My approach was to have places the kids can slide through the railing to get down, in the higher bed this is at the spot where the kid can get down on the lower bed. This works pretty good. The kids have NEVER fallen out of the beds in the last year and a half. The railing's height is determined by how active the kids are and how big of course. Mine (the railing, not the kids!) are approximately 30 cm and the the largest "holes" are not more than 10 cm in diameter.
A good way to make the railing is to find odd-shaped branches, put a couple of them together and that normally does the job. You can involve the kids again in this step, which is the part where you give the bed its look...
Step 8: Before You're Done- Test It!
This step might sound obvious, but I just would like to make sure I am not responsible for any broken arms or such things....
When the railing is ready have the kids test the stability of the bed while you are watching. Let them play around, find ways to climb up on the bed, see if there are spots in the railing that are too wide and if necessary add branches that close gaps or make it easier to get onto the bed. My experience is that the kids can climb a lot better than we would expect.
Ok, now all you need to do is send me a photo...