How to Build a Halfpipe

Snowboarding, skateboarding, and BMX freestyle are just a few of the most popular extreme sports today. The exhilarating speed and spectacular stunts are trademarks of these sports that contributed to its popularity. All of its adrenaline-pumping stunts would not be possible without a halfpipe.

A halfpipe is essentially two concave ramps set facing each other. Between these ramps is a flat transition, while a deck sits at the top of each ramp. These structures are often constructed out of wood, although metal sheet is also sometimes used.

Building a basic halfpipe is pretty much a straight forward task. It simply requires a basic plan and materials combined with a little construction know-how.

Required Materials

100 8-foot pressure treated 2 x 4ï¿½s
6 ï¿½- inch 4 x 8 pressure treated plywood
20 sheets ï¿½-inch CDX pressure treated plywood
12 cinder blocks
two 16-foot and 2 3/8- inch OD black steel pipe
3-inch galvanized deck screws
four ï¿½- inch by 6-inch angle bolts
construction adhesive

Required Tools

circular saw
chop saw
jigsaw
framing square
hammer
drill with bits and long #2 bit
level
tape measure
extension cords
eye and ear protection

Preparation of the Materials

Cut 8 ï¿½ – inch plywood into radius of ramp of 61 ï¿½ inches.
Cut 4 ï¿½ – inch plywood into decks of 3 x 8.
Floor joists: cut 70-2 x 4 x 8’s into 94 ï¿½-inch lengths.
Deck joists: cut 16-2 x 4 x 33-inch pieces.
Vertical deck supports: cut 16-2 x 4 x 32 ï¿½ -inch pieces.

Steps to Assemble the Halfpipe

Layout the exact location of the halfpipe by marking each corner of its dimension with cinder blocks. These blocks will serve as support piers of the structure. Use a string line to ensure that the site is level. Dig a shallow hole to lower the blocks into and keep the site level. Place a cinder block every 8 feet until all the supports are in place.
Prepare twelve ï¿½-inch 2 X 4ï¿½s to use as joists for the ramp. Line two side pieces that were cut earlier in parallel.
Measure 8 inches down from the cut out for the coping pit or where the arch begins. Attach the first joists with 2ï¿½ to 3ï¿½ deck screws. Keep on adding joists every 8 inches and double the joists when you reach 48 inches. Connect two sheets of plywood at the 48-inch mark.
Attach joists at the front and rear of the top deck. The joists at the front corner of the deck functions as the back shelf for the coping pipe. The first joist at the top of the curve functions as the base for the shelf. Set these at a right angle as this is where the grinding pipe will be placed.
Install the 2 x 4 x 33 deck joists. Repeat the steps above for the other ramp.
Move the skeleton ramps to the selected area for the halfpipe. Set each ramp on the cinder blocks on both ends. Once the ramps have been positioned correctly, begin constructing the frame for the transition or flat section.
Use two 96-foot 2 x 4’s and nine 94ï¿½-foot joists for the outer frame of the 8- foot transition. Once the 8- foot 2 x 4’s is secure, measure 12 inches on center to connect the joists. Use galvanized deck screws to secure the joists in place.
Attach the coping pipe once the framing is complete. Run the coping pipe along the entire width of the ramp. Make sure that it is smooth and seamless. Use two 16-foot 1-ï¿½ inch steel pipes.
Cut the pipes to its appropriate length and drill holes that will hold it in place. Drill two holes on the pipes on the same side, 20 inches from the edge.
Begin with the ï¿½-foot pilot hole and a 5/8-foot hole. Screw the pipe in place and mark the site of the holes in the coping sill area. Drill two 5/8-foot holes on the 2 x 4 piece. Secure the coping with anchor bolts. Make sure that the piping is secure with washers and nuts.
Attach the mid and skating layers once the frame is complete. Use exterior grade ï¿½-inch plywood for the mid-layers. Bend it appropriately to conform to the curve of the ramp. Screw the sub-floor into the frame. Then lay the skating layer using ï¿½-inch Masonite or Skatelite.

How to Do These Things

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