Small Arched,steel Shed. Moveable/Transportable. Possible Uses: Car Port for Small Cars or Motorbikes, Garden Shed or Workshop.

I am building small relocatable sheds from recycled materials. This one is made from two 8-foot trampoline frames clad with fencing panel sheet steel and sits on top of three farm gates.

Supplies

A couple of decades ago trampoline designs moved away from rectangles and became circular. Many used trampolines are discarded when the mat sustains damage but the frame is usualy in good condition. They can be bought for next to nothing or even obtained for free. The curved steel is hollow but quite thick and suitable for a number of different construction projects. Although galvanised the steel eventually develops rust so it is probably a good idea to paint or treat them for rust prevention.

For cladding I used 2nd hand fence panel sheet steel and leftovers, although roofing sheet steel is practically the same product. I bought 16 sheets for between five and ten dollars each. Usually sheet steel is utilised in one plane, i.e. flat, but of course it can wrap around curved surfaces perfectly.

Step 1: Assemble the Frame

Assemble two trampoline frames into four semi circles. Then stand them such that the T-pieces which normally point to the ground face each other. Connect these T-Piece junctions to each other with the straight poles which normal connect the trampoline to its feet. The length of the poles is determined by the lengh of the sheet steel, in this case two lengths with just over a centimeter of overlap.

On some frames the T-Piece junction part is removable and can be turned around to face the other way. More can be added as fencing suppliers and hardware stores sell them as "Downee" junctions/connectors". Most trampoline manufacturers use the same diameter poles, however the lengths differ as does the method of joining. Usually the poles are thinner at one end enabling them to be easily joined to each other. Usually the T-Pieces are large and the small end of the pole fits inside but some are small and the end of the pole fits over it.

Some trampolines have poles which are not narrower at one end but none have poles which are narrower at both ends. You can make such a pole though by joining two end to end with a short, slightly smaller pole inside and secured with a couple of screws.

Ideally you should be able to avoid cutting by buying a few fittings but if you do need to cut the narrow ends off some of the poles I suggest using a hacksaw and not an angel grinder for safety's sake.

Step 2: Attach Roof Sheets

While it is still on the ground attach the sheet steel and make any necessary adjustments before securing the poles in place with screws or pop rivets. This can be done by cutting the poles to length and fine tuned by how far the poles push into the T-Pieces.

Step 3: Stem Wall(raise on Top of Farm Gates)

As luck would have it the length of two sheets of steel was about 3.6 metres, a length which is commonly used for farm gates, and the width of the trampoline was almost 2.4 metres, another common farm gate size. I bought the three second hand farm gates for less than two hundred dollars.

Turn the farm gate upside down, as this will allow the shed to be easily moved by sliding and allows for easy connection to the already assembled roof. Lift the side of the shed roof up and insert slightly narrower poles inside of both the farm gate and trampoline frame and lower it down. These can be short sections of water pipes or some of the smaller diameter poles that come with trampolines and are used to hold up the safety netting around them.

Adding the second farm gate is the potentially dangerous part, as the full weight of the construction thus far must be held high enough in the air to insert these poles/pipes in the other side before lowering the roof down. What I did is ran two ropes over the roof to either side of the frame on the other side and used my car to slowly pull and carefully balance the structure at which point I applied the hand brake. It might also be possible to rest it on a step ladder or some lengths of timber but this must not be in the way of the gate.

Step 4: Brace With Back Wall

Next add the shorter farm gate to brace the structure. I used the U-Bolts that come with the trampolines to secure the safety netting, but you could easily drill through both tubes and bolt them together.

At this point I decided to see how well it would fit my micro car. It only just fits, but as the shed is only 2.4 metres wide I would have to let passengers on the left side out and park close to the that side to comfortably get out of the right hand side.

Step 5: Attach Sides

Now it's time to add the sheet steel by either screwing or pop riveting it to the frame. As the width was longer than one length sheet steel I had to cut and join it. I decided to make three segments out of the two colours. The 2nd hand fencing steel came with posts and rails made of rolled sheet steel. Notice how one of them fits nicely over the back gate.

Step 6: Add Window(s)

To make the window I used translucent corrugated plastic sheeting scavenged from kerbside cleanups. This should also be available at tip shops and demolition markets or from online 2nd hand marketplaces. The frame is a much narrower steel tube I found without knowing it's original purpose. It might be from a tramploine where the safety netting curves upward. It almost had the right curvature but I had to squeeze it a bit. I expect a suitable alternative would be plastic pipes/tubing such as electrical conduit or irrigation/waste water hose. Bear in mind that these kinds of hoses can be made more rigid by inserting a smaller hose within a larger one.

I used plastic elbows from the plumbing section of the hardware and some screws to secure a straight pole of similar thickness along the bottom. I ran steel strapping across it and riveted the plastic sheet to it. The window is hinged by some threaded rod such that there is still room to walk under it. It can be partially opened for ventilation or raised to horizontal by means of a strut either at the bottom or at the top from the inside. Another one of the rolled steel fence posts snaps over it at the bottom and it swings nicely in the breeze.

Step 7: Make and Hang Doors

For the front doors I have used the feet of the trampoline, two on each side, inserted into a short length of steel pipe which is secured to the shed frame. This functions as a hinge.

By cutting another one of the rolled steel fence posts close to the middle at 45 degrees I was able to fit it over the top of the doors.

Step 8: Add Trim

Although not finished the shed is already usable. Soon I will add a front window(identical to the back) such that it is raised as part of opening the shed. It will be high enough to walk under and to allow a car to drive in. The shed also needs to be braced at the front with a water pipe or flat bar across the entire width on the ground. The plastic drainage hose pictured in the "attach sides" step is cut along its length such that it snaps over the arch. I will continue to update this post with more photos and descriptions until the project is completed to my satisfaction.

Note that the width of this shed is less than two and a half metres which means it can be moved with a wide trailer or tilt tray by simply dragging it along with the farm gates functioning as skids.

This is my first post on Instructables but I have many more construction projects to add once this one is finished.