The mini half pipe, generally defined as a half pipe measuring six feet high or under, is one of the most fun ramps to skateboard. Most skateboarders prefer to build mini half pipes, because larger ones are more difficult to skate and require more skill to master. Mini half pipes also require less materials, less space and labour to build and, therefore, cost less. Building a half pipe can be a daunting task, especially for someone who's never had any carpentry or construction experience. With the right plans, tools, materials and site, the endeavour behind building a half pipe will pale in comparison to the fun and exercise the finished ramp offers.
Find a good spot to build the half pipe. The ideal site for a half pipe is on level ground, in a dry, well-lit area with few trees. Once the ramp is built, it's impossible to move, so this will be the ramp's permanent site. Set your concrete markers at the four corners of the flat bottom, and make sure they are level. Cut four pieces of 2x6s to create a square frame following your plans. Cut more 2x6s, and place them every 18 inches on centre to support the frame.
Draw the sides using a piece of string anchored to a screw as a compass. The curve on the sides, called transitions, should be a continuous circle from the flat to the top of the ramp. This is true for whatever size of half pipe your're constructing. Cut the sides, and attach them to the flat bottom. Next, frame the sides with 2x6s that are 18 inches on centre following the curve up to the top. Cut out a small notch at the top for the coping. Frame out the boxes for the platforms on each side (carefully follow your plans), and make sure they're level and square.
Add the surfaces to the ramp and the platforms. Cut sheets of plywood to surface the flat and the curved transitions. Use wood screws to anchor the plywood sheets to the 2x6 framing. Add another layer of plywood to the flat bottom and transitions; make sure to lay them in the opposite direction as the previous layers. Avoid lining up seams from the two layers. Cut off the plywood at the notch for the coping. Some plans call for a layer of tar paper before adding the final layer of waterproof Skatelite on the bottom and the flat. Follow your set of plans to finish by surfacing the bottom and transitions with a layer of Skatelite. Now you're ready to surface the tops of the platforms. Some plans call for surfacing with 2x4s, others with plywood. Using 2x4s makes the surface much stronger and more durable. Add railings to the back and sides of the platform to make them a safer place to wait and watch when not skateboarding.
Finally, cut the metal pipe to fit the width of your half pipe, and place it in the cut-out notch where the platform and the transition meet. Use a metal drill bit to punch four holes in the pipe. Use screws to anchor the pipe to the 2x6 framing the notch. Use a broom to clear any debris that may have accumulated on the half pipe.
Always keep your work site uncluttered and clean of debris. Check with the local Homeowner Association (HOA) to ensure they allow skateboard ramps.
Half pipes are large, potentially dangerous structures. Always follow plans, and seek professional help when needed. Always wear protective gear when skateboarding.