Backyard rink ice problems and fixes
Bumpy, cracked or chipped ice usually traces back to how the water went on. The City of Toronto publishes a troubleshooting table in its natural ice rink operating guide (October 2024), written for volunteer-run neighborhood rinks. It is the most specific cause-and-fix list I found from an organization that runs rinks. The table below follows it, and the sections after it add water numbers from the calculator.
Problem, cause and fix
| Problem | Cause (Toronto) | Fix (Toronto) |
|---|---|---|
| Rough or pebble ice | Too much snow on the ice, flooding while it snows, dull scrapers, or too little or too much water per flood. | Clear all snow before flooding, keep scrapers flat and sharp, and use the right amount of water. |
| Shale ice | Heavy flooding leaves pools that freeze on top while the water drains away underneath, leaving air pockets. | Scrape away the top to expose the air pocket, fill it with wet snow slush, then build up gradually with water. |
| Cracked ice | Excessively cold temperatures. Elsewhere the guide says warmer flood water cracks the ice below on nights of -23 °C (-9 °F) or colder. | Fill the cracks with wet snow slush and flood to even the surface. |
| Chipped ice | Brittle ice from severe cold. | Flood with water. The guide says frost-free water sources usually give water at 4 °C (39 °F). |
| Low spots | Heavy use in one area. | Flood with a pail of water in the evening, when nobody skates for the next several hours. |
| Frost boils | Excess water in the soil freezes and expands, heaving and cracking the ice. Water boils out through the cracks and freezes. | Cut out and remove the affected area, then build up again gradually with water. |
Toronto describes ground-level natural rinks. On a liner rink the soil cannot take water in, so I expect frost boils to be mostly a no-liner problem. That is my reading, not Toronto's.
How much water is too much
Toronto's spraying advice for the first coats says that if the water takes more than 15 to 20 minutes to freeze, you have put too much water down and should use less on the next pass. To see the size of the gap, the table compares a thin 1/16 in flood with a heavy 1/4 in flood on a level rink. Hose minutes assume 5 US gallons a minute, which is a guess; time a bucket at your tap.
| Rink (ft) | 1/16 in flood | 1/4 in flood |
|---|---|---|
| 20 × 40 | 31 gal 6 min |
125 gal 25 min |
| 30 × 60 | 70 gal 14 min |
281 gal 56 min |
| 40 × 80 | 125 gal 25 min |
499 gal 1 h 40 min |
Worked example, 30 by 60 ft: a 1/4 in flood is four times the water of a 1/16 in one, 281 gallons against 70. All of that extra water has to freeze, so a night that sets the thin coat may leave the heavy one wet at sunrise. The calculator opens with that rink for the first fill, which is a different job from these top floods.
Patching a low spot
A pail is a small amount of water. Pour 1 US gallon over a 3 by 3 ft patch (9 sq ft) and the film is about 0.18 in thick if it stays put. That is thinner than the 1/4 in flood above, and I expect it to freeze in the hours between skating sessions (my estimate, not Toronto's). The pail size is my example, not Toronto's.
Related
- Flooding a backyard rink: first fill and top floods
- DIY resurfacer: water per pass and the steps
- Snow on a backyard rink: clearing before you flood
- A backyard rink without a liner