Backyard rink on a deck or patio: how heavy is the ice?
A small flat rink on a deck or raised patio is a tempting idea: no slope to measure and the surface is already level. The catch is weight. I did not find guidance on what a deck can carry under a rink, so this page does the one thing numbers can do: it works out how heavy your water is. This page gives weights only. It does not say any depth is safe. Only a deck builder or structural engineer who has inspected your deck can say what it holds. Age, rot, rusted fasteners and how the ledger is attached all matter.
Pounds per square foot
Water at 0.01 °C is 999.8 kg/m³, which is 62.42 lb/ft³ (Engineering ToolBox, converted by me). One inch of water over one square foot is a twelfth of a cubic foot, so about 5.20 lb. Freezing swells the volume but keeps the mass, so the ice on the deck weighs what the water weighed. The load per square foot does not depend on rink size, only on depth:
| Water depth | 2 in | 3 in | 4 in | 6 in | 8 in |
|---|---|---|---|---|---|
| Load, lb per sq ft | 10.4 | 15.6 | 20.8 | 31.2 | 41.6 |
Water only. Boards, liner, brackets, snow and the people on the ice come on top.
A rink stays loaded
A rink stays loaded all winter, with boards, liner, snow and skaters on top of the water weight in the tables. A party on a deck lasts an afternoon. A rink does not come off until spring.
Total weight for small rinks
Level rinks, water only, in pounds and US gallons. The gallons are what you would hose onto the deck.
| Rink | 2 in | 3 in | 4 in | 6 in | 8 in |
|---|---|---|---|---|---|
| 10 x 10 ft | 1,040 lb 125 gal |
1,561 lb 187 gal |
2,081 lb 249 gal |
3,121 lb 374 gal |
4,161 lb 499 gal |
| 12 x 16 ft | 1,997 lb 239 gal |
2,996 lb 359 gal |
3,995 lb 479 gal |
5,992 lb 718 gal |
7,990 lb 958 gal |
| 16 x 20 ft | 3,329 lb 399 gal |
4,994 lb 598 gal |
6,658 lb 798 gal |
9,987 lb 1,197 gal |
13,316 lb 1,596 gal |
| 20 x 30 ft | 6,242 lb 748 gal |
9,363 lb 1,122 gal |
12,484 lb 1,496 gal |
18,726 lb 2,244 gal |
24,968 lb 2,992 gal |
Take a 12 x 20 ft deck with 3 in of water: 3,745 lb, or about 1.9 tons, from 449 gallons. Open that deck in the calculator for the liner size and board height, then change the numbers to yours.
Things to settle before flooding
My suggestions, not sourced rules:
- Ask who built it. Joist size, spacing and span decide the answer, and the footings and the ledger matter as much as the boards you can see.
- Get the deck checked first. Fewer inches means less weight, but it does not make a deck safe. The ice thickness guide lists the 3, 4 and 6 in rules of thumb, so you know what depth you are asking the inspector about.
- Plan for a leak. A pinhole in a liner on a deck drips through the boards onto whatever is underneath. Use the full liner and check the seams, see liner size.
- Keep snow off. Snow adds weight on top of the ice. The snow guide covers clearing it.
- Think about the thaw. Draining a deck rink means pumping or siphoning off the edge, see draining a rink.
A patio on the ground
A slab or paver patio at ground level sits on soil, so the load goes into the ground. That puts it closer to the case in the concrete and driveway guide, which also covers holding boards without drilling. Check the pitch of the patio first: most are sloped slightly for drainage, which the slope measuring guide shows how to read.