Step 6 - Plywood Surface
Materials required: 10 pieces of 3/8" plywood (untreated)
Now to start the halfpipe surface. You should use two layers of 3/8 inch plywood. Start by laying the first two sheets in the center like this
Dont lay them exactly in the center, but stagered by 8 inches, when you do the next layer, you will stagger the first two sheets 8 inches in the other direction, this is important to make sure the seems of the plywood do not line up. Notice how the edges of the plywood end up at a 2x6 support, this should be planned from the beginning.
Add the next pieces of plywood, laying them sideways on the halfpipe (opposite of how you just layed them), so it will look like this
again, each piece should have its edge on a 2x6 support
It will take two pieces of plywood on each side, the top piece will have extra, screw the top pieces in uncut, you can cut them later.
Leave the top pieces sticking out like this and start the second layer. This time for the first two sheets you cut one in half the long way (hot dog) and lay them like this. Again you do this so that the seems don't align. As I mentioned before for the first sheets of the second layer you stagger them 8" off center in the opposite direction that you placed the first layer, again this is so the seems do not line up. Like the first layer these sheets should end on a 2x6 support.
Screw in the rest of the second layer, again you will have extra plywood sticking out of the top. Now cut off the excess at the top.
You should cut the excess plywood off so the coping will fit perfectly, like this
Thats it, your mini pipe should now look something like this