Building a backyard rink on a slope
The water in a rink is flat, the yard under it usually is not. Whatever the ground drops from one end to the other gets added to the water depth at the low end, and to the board height there. That one fact decides the boards, the liner and the water bill.
Board height for each drop
A 30 by 60 ft rink with an even slope along its length, 3 in of water at the high end and 2 in of board above the water line. Worked out by the calculator.
| Drop over 60 ft | Deep-end water | Deep-end board, lumber | Water (US gal) |
|---|---|---|---|
| 0 in | 3 in | 5 in 2x6 |
3,366 |
| 2 in | 5 in | 7 in 2x8 |
4,488 +33% |
| 4 in | 7 in | 9 in 2x10 |
5,610 +67% |
| 6 in | 9 in | 11 in 2x12 |
6,732 +100% |
| 8 in | 11 in | 13 in over a 2x12 |
7,855 +133% |
| 10 in | 13 in | 15 in over a 2x12 |
8,977 +167% |
| 12 in | 15 in | 17 in over a 2x12 |
10,099 +200% |
Lumber is the smallest common board whose actual height covers the deep end (2x8 is 7.25 in, 2x10 is 9.25 in, 2x12 is 11.25 in). The percentage under the gallons is the extra water compared with level ground.
Measure before you buy boards
For how tall a board has to be before a slope is even a problem, see backyard rink board height.
Stake the four corners, run a level string between them and measure down to the grass at each stake. Enter the four numbers in the calculator to get the height for each side. The full steps are in how to measure slope for a backyard rink.
Measure in fall, before the snow. A yard that looks flat can still drop a few inches over 40 ft, and a drop like that can be the difference between a 2x6 and a 2x10 on the low side.
The deep-end problem
Deep water at the low end brings three things. It takes much longer to freeze all the way through, so the top can skin over while liquid water sits underneath. It pushes harder on the boards, and that push grows with depth. And it uses a lot of water: in the table, an 8 in drop more than doubles the fill.
Pwice, a rink kit maker, says a slope of more than 6–8 in causes uneven ice depth, so keep the drop small where you can. The calculator warns when the deep end needs more than a 2x12, the tallest single board it assumes.
Ways to handle a slope
- Turn the rink across the slope. Running the long side along the contour cuts the drop. The same yard that drops 8 in over 60 ft drops 4 in over 30 ft. Turned that way, the deep end gets 7 in of water instead of 11 in, and the fill goes from 7,855 to 5,610 gallons.
- Step the boards. Board height only needs to match the water at each point. Use taller boards on the low end and shorter ones near the high end, and let the sides step up or taper between them.
- Build up the low end. Some people pack snow or slush into the low end, wet it and let it freeze before laying the liner. It needs cold weather and patience, and it brings the floor closer to level so the water is shallower.
- Make it shorter. The drop scales with length. A rink that is 20% shorter along the slope has a 20% smaller drop.
- Shim and stake the boards. On a slope the boards want to slide downhill. Brackets or stakes on the outside, and shims under board ends where the ground dips, keep the frame square.
A deeper rink also needs a bigger liner, because it has to climb the taller boards. The liner size guide covers that.