An unprotected stone building block in Rust decays from full health to nothing in 5 hours. Wood takes 3 hours, sheet metal 8, and armored 12 — the full set is in the table below.
Decay only runs on structures that are outside the range of a stocked Tool Cupboard. A block inside an upkept cupboard's radius does not decay at all, which is why the practical question is never "how long until my base decays" but "how long will the cupboard hold out".
Damage is applied gradually across the decay window rather than all at once, so a block found at half health has roughly half its decay time left.
Working out a specific case? Decay calculator →
Times are for a block at full health with no Tool Cupboard in range. Damage accrues linearly, so a block at half health has about half of this time remaining.
| Building tier | Block health | Full decay | HP lost per hour |
|---|---|---|---|
| Twig | 10 | 1 h | 10 |
| Wood | 250 | 3 h | 83 |
| Stone | 500 | 5 h | 100 |
| Metal | 1,000 | 8 h | 125 |
| Armored | 2,000 | 12 h | 167 |
5 hours from full health, if it is outside the range of a stocked Tool Cupboard. A stone block has 500 HP and loses it steadily across that window.
3 hours unprotected — the shortest of any real building tier. Twig is shorter still at 1 hour, which is why twig is never left in a finished base.
Yes, as long as it has resources in it. Building blocks inside a stocked Tool Cupboard's radius do not decay; the cupboard consumes upkeep resources over time instead. Once it runs empty, decay resumes from full health.
8 hours from its 1000 HP. Armored is the most durable at 12 hours and 2000 HP.
No. Decay is applied gradually over the tier's decay window, so a partially decayed block still stands and can be repaired. Entering the current health into the decay calculator gives the remaining time rather than the full-tier figure.
Decay rates and block health come from the RustTools decay data set. Values are read from the RustTools game data set, the same data the calculators run on. Data on this page was last verified against Rust in August 2026. Facepunch balance patches can change these values — see the changelog for what has been re-checked. RustTools is an unofficial fan project and is not affiliated with or endorsed by Facepunch Studios.